MadModder
Gallery, Projects and General => Project Logs => Topic started by: S. Heslop on May 28, 2014, 02:48:14 PM
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I'm trying to build an electric bike. It's hard to find information about directly that on the internet since most people like to call installing an overpriced kit as 'diy/ homemade'.
One thing giving me alot of trouble is sourcing a suitable motor. On ebay looking for scooter motors and DC motors I can't find any over 350w, and searching on google just gives me a load of shady Chinese websites.
Are there any good websites/ catalogues for buying spare and surplus motors in the UK? Or could I maybe try looking for something else. I think I once heard a thing about using car alternators as motors for kiddie cars.
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Older brushed generators would probably work.
I know it sounds weird but what about a brushless R/C motor and ESC?
Raynerd could probably help out there, since he built a CNC motorized mill spindle with one.
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How about this one:
http://www.giantshark.co.uk/product/169401/xyh63-54-250kv-65a-outrunner
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I don't know your price range Steve, but if you only want to get 500 watts out of it, the above would be nicely overbuilt, yet have the advantage of a low kV (meaning revolutions per volt) which will reduce your gearing down requirements.
If you limit it to 500 watts, you might be able to get by with an ESC of say 60 amps (rather than the more expensive recommended 100a ESC). You would need a slip clutch or some means of preventing over current/stalling, but probably would for a 100 amp ESC as well. Also, of course a throttle stop.
The lower the voltage the easier the gearing is going to be. 4 Lipos appears to be the minimum recommended for this motor, which is about 15 volts -- that would still yield about 600 watts @ 40 amps. Motor RPM would be about 15V x 250 kV = 3750 RPM
If you went to 5 lipos, that's about 19 volts and you would run a max of about 25-30 amps to get you in the 500 watt range. Even a smaller ESC, but gearing ratio would need to be higher. Motor RPM would be about 19 V x 250 kV = 4750 RPM
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Thanks for the reply.
Yeah that looks like a good motor. It's much smaller than the scooter motors I was looking at too, and about the same price (if not cheaper!). I guess the brushless controllers bring the price up though but it's still within what i'm happy to pay.
I guess the next problem is figuring out how to gear the motor down with the tools I have.
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Steve also for a controller for the ESC (ie throttle), you can use what's called an R/C "servo tester" -- they are very cheap from some sources. They generate the pwm signal the ESC needs to set the motor RPM.
That motor listed by the way, has probably only limited availability. Looks like greatshark has sold out of that brand for most of the other motors in the line. Though they say " by special order" for availability on the others, I doubt it.
I've used those same red motors branded as "EMP" and have had good luck with them.
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When it says outrunner does that mean the outer casing of the motor is the part that spins?
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The outer case is fixed to the spindle so that they both turn at the same time. From what I can gather they have more torque than the in-runner configuration.
Regards, Matthew
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An outrunner has an outer ring that contains the magnets, and spins and is usually connected to the prop shaft. The coils and armature are stationary. Efficiencies can be up as high as the 90+% range. Higher than inrunners. Cooling is usually easier also.
One consideration would be to support the shaft outside of the motor (add a pillow block) in a geared, or chain drive for a bicycle configuration. An airplane loads the motor axially in thrust. Gearing will load it radially,
But it's not hard to add an external bearing. If needed also, the motor shaft can be replaced with a longer one fairly easily. Typically in a mill adaptation, an ER collet arbor is substituted for the original motor shaft. I think Reynard's forum thread on his CNC mill conversion goes into this.
Here are examples of servo testers that would provide the throttle potentiometer and control circuit for the ESC. (ESC stands for Electronic Speed Controller):
http://www.ebay.co.uk/sch/i.html?_nkw=servo+tester
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Thanks again.
I'll order that motor and a controller tomorrow most likely. Still gotta think about it for a bit for £90.
All this motor stuff is really making me feel like a dunce though. Hopefully I don't cock it up!
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Yes, thinking it over is good. It does mount up. And maybe someone else will have a lead on a less expensive way -- I'm going to look into that mention of an alternator conversion for a kiddie car. Sounds interesting.
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Coming at it from the opposite direction, it looks like R/C modelers have been using ESC's to power auto alternators as motors. Here's a really extensive thread on the topic:
http://www.rcgroups.com/forums/showthread.php?t=905411
also, large ESC's can be had for considerably less than the place I linked to, if you are willing to purchase direct from China.
http://www.ebay.co.uk/itm/RC-Model-Airplane-Helicopter-60A-Brushless-Motor-Speed-Controller-ESC-SL025-/251528990050?pt=UK_ToysGames_RadioControlled_JN&hash=item3a904bcd62
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Alright, ordered the motor, speed controller, and servo tester. Thanks for the help.
Y'know I'm always amazed that you can order things for as little as £2 from China and still have free delivery.
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Well I hope your order is fulfilled.... :scratch:
Giant shark use to be Giantcod, run by Rob Carpenter until he sold up...
Gs is now owned by the same outfit that publishes ME MEW mags.... They've been transferring stock ready to hike up prices in line with other retailers....So our cheap products from China are drying up.....sadly....
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Well I assumed a UK outfit would be more reliable than an overseas one, and more easily accountable if not. Apologies if that is a questionable seller. They list the part in stock and I don't see why they wouldn't ship it. But I don't know local sellers there like I do here.
If there are any problems, similar motors are available from Chinese sources, and I think HobbyKing UK, (though I'm no fan of HK and would likely recommend others if ordering direct from China).
I'm guessing Steve paid by PayPal, or credit card, so if it isn't shipped within a week he can speak to them locally, or cancel and purchase elsewhere.
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They shipped very quickly. The motor arrived this morning!
And it looks good. Even came with a mounting plate and an attachment/ nose cone for a RC propellor. Can't test it until the speed controller arrives from Hong Kong though. The servo tester also arrived and I bought a free wheel from halfrauds. It's exciting when things start to come together, but there's still a ways to go.
Thanks once again for the help.
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Hey Steve great!! :thumbup:
Steve -- just a suggestion -- don't over-rev it testing -- I'd put a load on it like a dummy propeller -- just a good straight grained piece of hardwood, balanced, roughly the size of a propeller to suit.
Don't stand in line with it, and be sure to bolt that motor down solidly before applying juice to it -- they can really torque around.
Be cautious!
Also, those bolt-on prop shafts are usually aluminum -- the loads on a plane motor are primarily axial, and not radial, so be cautious with that setup if trying out something other than a propeller.
You'll probably want to replace the steel motor shaft -- I think it's 10 mm -- with a longer steel shaft to take radial loads, and also support the longer shaft in an external bearing.
Well, exciting that you're on your way!! :dremel:
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That's a good suggestion. Also supporting the shaft with another bearing wont be a problem now that the original gear plan isn't going to work.
I might have to bite the bullet and spend £30 or more on gears. I'm still really surprised by how expensive gears are! The two auctions for lathe change gears I was keeping an eye on ended up reaching nearly £50 so there goes that option too. Maybe i'll get implausibly lucky at the boot sale tomorrow, or at least pick up some cheap power tools to take apart (although I think the motor shaft having a gear milled into the end is pretty standard with them).
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What about chain drive? Sprockets and chains are available from tractor/farming supply companies.
Have you worked out your wheel size and some idea of what kind of reduction ratio you want to try?
The larger the wheel size the greater the reduction needed.
Also, how many volts and what type of battery will you be trying?
It might be economical for testing and ballpark estimating to just find a used 12V car battery and make a wooden kart and see what that will do, then move on to whatever else you have in mind once you've established a baseline for components.
Also, aren't there motorized bicycles that use friction drive against the wheel rim? A clutch and reduction rolled into one, and a pretty big reduction ratio.
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Yeah i've tried a few. I think I might have it sorted though.
Placed an order for 2 sets of these.
http://www.amazon.co.uk/Repair-Spiral-Pinion-Makita-4100NH/dp/B00EZCQO7W/ref=lh_ni_t?ie=UTF8&psc=1&smid=A50DZI580G3JX
If it works out it'll be very cheap! Although the ratio is a bit low, the rear wheel will be turning at about 370rpm if the motor is going at 6000rpm. That'd be close to 30mph and might not give me alot of torque, but i've really got no frame of reference on how much is required and how much the motor supplies.
Here's the plan so far though.
(http://i.snag.gy/3ONMI.jpg)
There'll be a chain connecting the gearbox to the wheel's sprocket. It's a bit of a crazy plan, gripping a sprocket to the center hub (opposite to the existing sprockets) of the rear wheel via an aluminium block.
The things I'm concerned about is if the gearbox and motor will fit well in that small space between the frame and the wheel (I don't want to put it too far forwards in case it hits my legs as I pedal) and if there'll actually be enough of a gap to feed the chain through. I might need to make some kind of idler to push it down and out of the way maybe.
If it works out it should be a pretty good system though. The two main types of DIY electric bikes i've seen either turn the rear wheel via friction on the outside (which seems like it would have alot of problems), or turn the pedals (which would be tiring to keep up with, but I guess that's more of a power assist for steep hills). The free wheel I bought should ratchet if I pedal without the motor, so I won't be fighting against a gearbox and motor when purely peddling.
Boy i'm really using alot of weasel words. I'll honestly be surprised if this works out first try, but i'm having fun non the less!
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What about chain drive? Sprockets and chains are available from tractor/farming supply companies.
Have you worked out your wheel size and some idea of what kind of reduction ratio you want to try?
The larger the wheel size the greater the reduction needed.
Also, how many volts and what type of battery will you be trying?
It might be economical for testing and ballpark estimating to just find a used 12V car battery and make a wooden kart and see what that will do, then move on to whatever else you have in mind once you've established a baseline for components.
Also, aren't there motorized bicycles that use friction drive against the wheel rim? A clutch and reduction rolled into one, and a pretty big reduction ratio.
I'm aiming for 24 volts. I've got a whole bunch of old RC car NiCd packs I thought I could rewire to test it, and if it works out I'll go hog wild and build a gigantic lithium battery. I was thinking of using 12v sealed lead acid batteries, but i've been reading that they can't really supply enough current to keep up with brushless outrunners.
I live in an ex industrial area, all centered around the long gone Connsett iron works. But that means there's a whole load of disused railway cycle paths (complete with viaducts!) that go all over, and one goes right by house. It's a silly idea but I thought I could ride the bike up to my grandparents. I visit weekly and the bus fare costs £7 just to get there. My grandad usually drives me back home but he really doesn't feel comfortable leaving my grandma alone for too long in case she injures herself when he's not around. And I sure as heck can't afford my own car on a student loan.
But yeah i'd be surprised if I could produce anything rugged enough to survive long weekly trips, but at least it's all downhill back home if something breaks!
Y'know I never thought about running a motor on the wheel's rim. I'd only seen photos of people running them against the tyre. If I had a bike with disc breaks that might work well, but with the rim breaks on this bike I can't think of anywhere I could easily attach it.
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Steve I just looked up figures for that motor and them ran them through Motocalc as a fictitious airplane to try to get some figures out of it.
As an estimate at 5700 rpm and 24 V and a 7 cell lipo pack you should be hitting it just about at your target power -- 485 watts output from the motor with an additional waste wattage of 66 watts, estimated motor efficiency 88%, current 23 amps.
Hypothetical, and based on assumptions and mfr's figures for idle current and resistance , but I'm pretty good at monkeying motocalc and I tend to get good results.
Will 500 watts motor output push you an your stuff at 30 mph? Dunno that part. But I'm rooting for ya!
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Yeah i'd be surprised if 500w reached 30 mph but it should be enough to push me along under its own power at a lower speed. I kinda wish I ordered 3 sets of gears now! Although with a bigger gear box I won't be able to fit in the space i've got...
I guess I could always go for a bigger motor if needs be. I wonder how the tiny gears would hold up too. And i'm also wondering how speed controllers designed for RC planes would hold up. I guess you only learn by making mistakes~
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A very interesting project.
Unless I'm missing something obvious I don't think your Halfords freewheel is going to work on the left hand side of the bike (unless you try to ride it on battery power backwards)!
Going out on my bike now - 80 plus miles into Cheshire. I may be wishing I'd got electrical assistance for the big hill a mile from home.
Cheers.
Phil.
Edit: I've just been thinking about this on my ride and of course you can fit a single speed freewheel either way round but you will need a left hand threaded lock ring to stop the freewheel unscrewing. You can buy hubs which are designed for fixed on one side and free on the other which would do the job.
Just sat in a cafe waiting for my cheese and onion toastie.
Phil
Last Edit: It looks like not all single speed freewheels will fit the wrong way round. Phil.
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I'm watching with great interest!
You will need to think about cooling for this motor. In an RC plane, it has the propeller wash cooling it - on your bike it has the draft from going forward when you do - up to about 30mph in your estimate. That's nothing like enough I believe. So you need to moount a little blower and shroud on the shaft as well.
Looking forward to your results and reports - good or bad!
Cheers,
Joe
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Here is a great place for dc motors. http://www.robotmarketplace.com/products/npc_ungeared_motors.html
I have been running the black maxx on my bike for the last 6 years.
http://ivanbennett.com/e-cycle.html
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The heat load if the above calculation is correct will be ~60 watts at full power. So think of a 60-75 watt light bulb.
On the plus side for cooling this is a relatively open frame motor made largely of aluminum with an outrunner spinning around, and the bike is traveling, so in early tests just put a hand on the motor perodically -- the best temperature gauge for this kind of thing. And if it feels hot, add a fan.
Steve you mentioned questions about motor torque. Given the RPM and assumed power, seems it should be possible to solve for torque. Looking it up on the internet I found the equation:
power = torque x 2pi x rotational speed
so
torque = power(watts)/ (revs per sec * 2pi)
so
torque = 500/ (5700/60 * 6.28)
torque = .84 Newton meters (or .62 foot pounds)
A 26" wheel at 30 mph is doing 388 rpm (if I also got that right --- better check that, too) so your final reduction is maybe 5700/388 or 14.7 to 1.
If you had a 3 to 1 sprocket ratio on the chain drive, your gearbox ratio would be 14.7 / 3 or about 5 to 1.
So torque out of the gear box would be about 5 x .84 = 4.2 Nm or 3.1 ft lbs at that speed.
Could be a lot of incorrect assumptions or outright units blunders here..... take with a grain of salt! :doh:
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Here is a great place for dc motors. http://www.robotmarketplace.com/products/npc_ungeared_motors.html
I have been running the black maxx on my bike for the last 6 years.
http://ivanbennett.com/e-cycle.html
Hey I remember finding that website when looking electric bike stuff up. It looks cool as heck but i'm not sure on the legality of a purely motor powered bike in the UK. In the UK Segways are illegal to ride on both paths and roads (not that i'd ever want a segway).
I was looking at youtube again last night and found this (https://www.youtube.com/watch?v=0AVaR7jzYjo) video. He doesn't show much but it looks awfully similar to what i'm planning. I did think about mounting the motor there originally, but I didn't like the look of the motor being so exposed.
Looking a bit further this website looks like it could have some good information on it: http://endless-sphere.com/forums/viewtopic.php?f=28&t=29531
Keeping the motor cool was something I was concerned about. Another thing that bothers me is maybe getting my parachute pants tangled around the spinning outer case, so maybe a shroud around the motor won't be a bad idea.
If I figured it out correctly the free wheel should work with it the right way round. It still shouldn't be too much of a problem to flip it though, i'd just need to cut grooves to help tighten it.
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The heat load if the above calculation is correct will be ~60 watts at full power. So think of a 60-75 watt light bulb.
On the plus side for cooling this is a relatively open frame motor made largely of aluminum with an outrunner spinning around, and the bike is traveling, so in early tests just put a hand on the motor perodically -- the best temperature gauge for this kind of thing. And if it feels hot, add a fan.
Steve you mentioned questions about motor torque. Given the RPM and assumed power, seems it should be possible to solve for torque. Looking it up on the internet I found the equation:
power = torque x 2pi x rotational speed
so
torque = power(watts)/ (revs per sec * 2pi)
so
torque = 500/ (5700/60 * 6.28)
torque = .84 Newton meters (or .62 foot pounds)
A 26" wheel at 30 mph is doing 388 rpm (if I also got that right --- better check that, too) so your final reduction is maybe 5700/388 or 14.7 to 1.
If you had a 3 to 1 sprocket ratio on the chain drive, your gearbox ratio would be 14.7 / 3 or about 5 to 1.
So torque out of the gear box would be about 5 x .84 = 4.2 Nm or 3.1 ft lbs at that speed.
Could be a lot of incorrect assumptions or outright units blunders here..... take with a grain of salt! :doh:
Thanks for doing the calculations. To be honest though i've got no real frame of reference for those values, and Google isn't giving me any useful information. Yeah though with this gear reduction, and the motor running at 6000rpm, I got about 370 rpm on the 26 inch wheel.
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I mocked up the placement of the motor today with a block of wood, and it turns out it was in the way of my legs. So i'll have to mount the whole thing elsewhere.
Eventually I came up with this over complicated monstrosity.
(http://i.snag.gy/rO9Yl.jpg)
It has a v-belt that might serve as a clutch and reduces the rpm of the wheel down to 250, but it might not be so efficient.
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Could you make a expandable pulley to vary the ratio? that way you would not need a transmision.
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Could you make a expandable pulley to vary the ratio? that way you would not need a transmision.
They're too expensive but it's just made me wonder why I don't just replace the sprocket on the rear wheel with a huge pulley so I won't have to bother with gears.
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Belts waste a lot of power, and there isn't a lot to spare. Chain and sprocket would be better.
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But if clutching is a necessity, I also think that the friction drive against tire or hub has got to be the simplest of all, with a really good reduction ratio -- probably a 2" dia drive would get you in the ballpark, but easily changed-- maybe from a boat rubber trailer roller.
And this has been done on bicycles a lot -- I think I remember them in France. Aftermarket adaptations of standard bicycles I believe.
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I also remembered why I gave up on pulleys earlier. I don't have the space between the wheel and frame! Or anywhere good to mount the motor.
Found this from googling a bit. I didn't think about using a motor on each side but that seems expensive. Although maybe not much more than spending a fortune on metal...
Can't find any videos of the thing actually pulling a person though.
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Steve, what about an idler on the other side? You'd still get the pinch action....
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Steve, what about an idler on the other side? You'd still get the pinch action....
I feel silly for not thinking of that myself.
Yeah this seems like a better idea now. It's gotta be easier to build than the whole stupid system I came up with.
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This looks like maybe a tire drive:
(http://www.flmotorbikes.com/photos/SDC10977.JPG)
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A little more searching -- this is what I remember (and from the pic, looks about the right time, too:
(http://www.velosolex.co.uk/Solex8.jpg)
Velosolex
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Looking on youtube it looks like people even produce and sell kits to turn chainsaw motors into tyre drives. Seems like it'd be noisy to ride with though.
Just measured the front forks of my bike. The second-hand bike I bought has some real huge aftermarket forks.
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Here's walkaround and a ride on a Solex.
I detect a reluctance to stop for any reason once moving.....
Does look like fun though!
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Here's walkaround and a ride on a Solex.
I detect a reluctance to stop for any reason once moving.....
.
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Does look like fun though!
Steve
I think the only reason he ever slowed down was to prevent a "T" Bone. :lol: :lol:
I am enjoying following along on this one. :D :D
Cheers :beer:
Don
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I think the driving friction would wear out the sidewall too fast it's better to have it ride on the tread, depending on what tire you use some have fairly deep distinct treads offering possible tire/drive roller engagement. A buddy at work had a weedwacker motor on his bike and drove it from Calgary through the mountains to Vancouver bc from there he started heading north up into the Charlotes. It would be a hell of a holiday!
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Well it looks fun but I was waiting for a car door to open :D he was cutting it close to most vehicles or so it seemed but could just be the camera. Might be a candidate for the Darwin award! One thing to remember is they were not designed to stop at any great speed!
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Yes Tom, Don, reminded me of of The French Connection in a sort of 20 mph bicycle way, if I can put those two things together....!
I kept pulling my right leg in to prevent hitting a parked video car!
Definitely not sidewall drive as a possibility vs tread, Tom -- I was thinking of the metal rim and a rubber drive.
Steve, Just as a gut feeling I think 500 watts isn't going to do 30 mph, and so the ratio should be aimed at slower speeds w/ motor running ~ 6000 rpm. If you optimized for say 15 mph @ 6000 rpm, you could run a killowatt for higher speeds without changing ESC or motor at your projected 24 V batt supply. That would be about 40 amps x 24 V. Your ESC is a 60 amp controller.
So say bike wheel is turning somewhere around 185 RPM and motor 6000 rpm, and work out the ratio from that, or even lower speed.
I think if you do wheel drive the rubber driver is going to end up somewhere closer to an inch plus in diameter then -- but I haven't done the math.
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I bought a 100A controller but i'd still like to keep the amps as low as possible, with it being designed for RC planes most likely. So yeah 15mph might be a good bet.
A nice thing about this drive idea is that I can easily just switch the contact wheel out for something smaller if needs be. To reach 185 rpm on the outer wheel the contact wheel would be 40mm diameter. Although at that size the motor would be getting uncomfortably close to the spokes so i'm going to try 50mm, giving the bike wheel an rpm of 230.
One thing i'm wondering is how do things work in terms of using the speed controller to run the motor slower than 6000rpm? As in, would it put more or less strain on the controller/ motor?
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Steve, the ESC does run the motor slower than 6000 RPM when the throttle is reduced -- the ESC changes its timing to create the reduction in speed.
The main strain on the ESC is if the amperage exceeds its rating.
It takes about 24 volts to turn this motor at 6000 RPM.
How much current it takes depends on the load at a specific RPM
It might never reach 6000 RPM if the load is too great before that point.
An ammeter and a fuse are important to have in line while testing. Check your current draw with the particular setup as you test. Gradually increase throttle while watching the ammeter. Stop when you get to 20 amps (or whatever you decide) This will give you a maximum operating speed for the current limit that you want to specify.
Optimizing your setup by test would would mean that, if the maximum safe operating speed of the motor, by your specified current limit, is considerably below your 6000 RPM target, your gear ratio should be increased until they correspond. This will reduce the top speed of your bike until it matches your power specifications (500 watts @ 24 volts).
Any further speed increase will require more power.
If you are running under 6000 RPM at spec'd amps you are not sending effective full battery voltage to the motor, and are therefore running less than 500 watts. You are running at whatever amperage you show times the effective voltage.
ps. that's my understanding -- could be a mistake in it -- others chime in, please!
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Let me just simplify that:
Under test with typical load on the bike with a 24V system, approx 500 watt desired, 24 amp spec limit on a 250 kV motor:
Test 1: Ammeter reaches 24 amps at 2000 rpm. Servo controller knob (throttle) is not at max.
Conclusion: gear ratio too low, wattage less than 500 watts
Solution: reduce diameter of rubber spindle on wheel. Bike speed should actually increase (even though gear ratio is increased) because you are absorbing more power.
Test2: Ammeter reaches 24 amps at 6000 rpm. Servo controller knob is at max (full throttle).
Conclusion: gear ratio correct for wattage. Full 500 watts available. But bike is still too slow for satisfactory performance.
Solution: Increase spec for amperage and wattage. Since ESC servo controller is dialed all the way up in this case and you have no more throttle range, you will need to decrease the gear ratio.
If you do that, 6000 RPM (and full throttle on servo controller) will then be reached at a higher figure than 24 amps.
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Ah, thanks for clearing that up. Shame the speed controller is coming all the way from Hong Kong, that could take a good while yet.
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I have a pair of motorcycle sprockets here if you want them, not new but good, 420 chain size.
Lyn.
PS: may even have a new DID chain as well..
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Great Steve! :smart:
I've had some things from HK arrive in 3 weeks and some in 5 days even without extra postage.
One more point about load and power -- hills will obviously make a difference to amp draw. I'm guessing you'll have to keep an eye on your ammeter on a hill, and slow down until amperage is in the comfortable range again.
Not entirely sure how this is all going to work out -- as I'm really used to airplanes -- it will be really an interesting thread to see how it all works out in practice instead of theory. :coffee: :coffee: :coffee:
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I have a pair of motorcycle sprockets here if you want them, not new but good, 420 chain size.
Lyn.
PS: may even have a new DID chain as well..
Thanks for the offer but I don't think I really need a chain and sprockets any more with the friction drive.
Not entirely sure how this is all going to work out -- as I'm really used to airplanes -- it will be really an interesting thread to see how it all works out in practice instead of theory. :coffee: :coffee: :coffee:
Yeah i'm excited to see how it works out too. It's kind of been a lifelong dream to stick a motor on a bike, but I never really knew enough to manage it. I still don't know enough, but having the internet helps!
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The gears just arrived in the post this morning, they're really not bad for £5 a pair, and that's everything now delivered.
(http://iforce.co.nz/i/4jwafij1.wlb.jpg)
As for the plan, I spent a while fussing and figured the best way to go about it would be to build a sturdy carrying rack on the rear of the bike for the motor/ idler to pivot on. It's a bit of a clumsy looking design but it's the best I could come up with! A spring on the lower of the 3 bars on the arms will hold the rollers against the rim, and the top most bar will hopefully act kind of like a caliper brake (controlled by cable) to release the rollers from contacting the rim if I want to pedal.
(http://iforce.co.nz/i/dmq05gzm.cof.jpg)
Here's a still from some video I took. I made the punch from a motor shaft, and it's the first piece of steel i've ever successfully hardened thanks to John Doubleboost's video. Heating it till it stopped being magnetic and then quenching in oil did the trick.
(I just noticed that they kinda look like the British Isles. It might be sub-conscious since it's all britain this britain that on the tv at the moment!)
(http://iforce.co.nz/i/rq4svarv.vx4.jpg)
I went to the boot sale today to buy a better jigsaw. I was surprised to see so many people at a Wednesday boot sale. I guess i'm not the only person unemployed in the north east! I also picked up a nice new bench grinder and wrecked arms carrying it home on the bus.
In other news, I've been trying to buy batteries off of ebay. I guess the word got around that laptop batteries were a good source of cheap lithium ion cells. At 8am yesterday morning I decided to try bid on an auction that was at £12 for 20 used batteries, but in the last 5 seconds it jumped up twice to £50! I suppose even at that price it'd still be cheaper than the £500+ they charge for dedicated eBike packs.
I've got a bunch of mismatching NiCd RC car packs I might try rewire to test the motor, but first I want to get some of the metalwork done.
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Wow, great drawings Steve!
Would laptop batteries have a high enough C rating for the motor? They should be able to deliver close to 100 amps. Seems like R/C batt packs would be the cheapest and most suitable -- even the low cost ones are 20-30 C. Probably cheaper to put together multiple smaller packs than buy a larger pack. 3S and 2S packs are often the lowest cost per watt hour.
At 20 C and the minimum possible capacity you'd need a 7S 5000 mah pack.
You could make up that from a series hookup of (for example):
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=31952
http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=32119
You might want bigger capacity than that, which is fine if you can afford it. But it may be more cost efficient then to start paralleling packs -- you'd have to work it out.
A word of warning about HobbyKing which I just used as an example. Never order batteries from them overseas -- ONLY buy from the UK warehouse, and ONLY if the item is listed in stock. Their customer service and honesty are not beyond question in my experience, and you could wait months to receive an order -- or even never receive it. Generally orders from the local country HK warehouse are reliable, but sometimes they gouge you on postage. If you use another source for batts that you know well, that's a good option.
I use Zippy brand batteries in my planes and they are a good low cost reliable batt.
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I should mention, of course, and probably you already know that Li-ion cells like laptop batts are safer than Li-poly batts like R/C batteries. But both need special chargers, or you run a real risk of fire and explosion. Nothing to fool around with.
In my opinion the best Li-poly chargers are the ones that charge each individual cell through the balance plug, rather than the type that charge across the whole pack and require that you periodically discharge and balance individual cells. The former is simpler, faster, cheaper (for the charger) and foolproof.
There are other cells which are safer -- A123's or LiFe I believe, but they are a different voltage per cell and more expensive so the number of cells etc. would all be different.
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I found this real jumble of a thread on endless sphere. Any decent information on how to do anything is hard to find. I'm not a fan of the ES forums in general.
http://endless-sphere.com/forums/viewtopic.php?f=14&t=26383&sid=a0ae404381381478ccb07127d6820426
I'd assume laptop batteries are adequate because a fair few people seem to be using them for electric bikes.
But everyone seems to be using them now so the price of second hand batteries has really gone high. Looking at those hobbyking batteries linked, at 5Ah and £15 each, £60 worth (not far off what people are paying for the old laptop batteries) would make a 20Ah cell, which is pretty adequate. Plus it probably won't require all the fiddling to sort and test the cells.
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Sorry Steve, but that's 10AH for that money.
You need one each of the 4S and a 3S (S stands for cells in series) to make up the 7S you need for the voltage your system was spec'd at (if I remember correctly). That's why I gave two listings -- one for 3S and one for 4S packs.
In other words you connect a 4S and a 3S in series to make the equivalent of a 7S. It is still 5 AH total.
You could hook two of those sets together in parallel to get 10ah -- so that's 4 batts together and your 60 quid.
Used laptop cells might not have a full life or capacity left -- usually they don't, in my experience.
1 Lipo cell = 3.7 V nominal
so
3S = 11.1 V nominal
4S = 14.8 V nominal
7S = 26 V nominal
10Ah still seems like a usable amount if your target consumption is 500 watts:
10 Ah * 26V = .26 kWh
.26 kWh / 500 W = ~ half hour duration at full design power
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One caution, remember you now have a 2.6kW capable motor system, not just 500 watts. If you (well, I mean not you but uhh, somebody else...) starts hot-rodding around you could conceivably get a 6 minute duration at max throttle before you wrecked your batts.
Absolutely essential to have a voltmeter on board as well as an ammeter. You would want to switch off and start pedaling at a red line minimum battery voltage. And always keep throttle below your 100 amp max ESC rating. 500 watts is going to be more like 20 amps.
And a 100 amp fuse, and box of spare fuses as well.
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One of each of those batteries costs £35 (although maybe they'll rob me with delivery charges). I suppose it's not too much to take a risk on, and if it works out I can buy maybe a couple more packs to get more range.
I also need a balance charger. I see this (http://www.ebay.co.uk/itm/IMax-B6-Digital-LCD-Lipo-NiMh-battery-Balance-Charger-UK-Delivery-/351012088107?pt=UK_Sound_Vision_Battery_Chargers&hash=item51b9f3692b) one in alot of videos and the price doesn't seem so bad.
I guess I should buy a better multimeter too since my current very cheap one isn't that reliable.
The costs add up! Usually I try not to think too much about the price of things and get surprised when I suddenly run out of money, but for this project i'm keeping a log of everything I spend. I'm curious to see how much I spend in total (tools n all) so I can compare it to just buying an electric bike. I also suspect if I make a video it'll be the first thing people will want to know.
eBike videos on youtube tend to have real bitter comments. People getting upset that it was based upon a cheap bike, people getting upset that it's cheating and an affront to the purity of cycling, people getting upset that it's too complicated for them to bother building, etc. So i'll be interested to see how a video I'd make would fare.
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Well the secret delivery cost and paypal's own currency conversion being off by a few pounds bumped the price up to £43.54 for the batteries.
And just like that i've almost spent almost £100. It's frightening how quickly you can buy stuff online. I had a friend who spent something like 150 USD on useless mobile phone software when he was drunk one night. He had that one click purchase so there was really nothing stopping him from going hog wild.
So far i've spent about £150 on materials for the bike, including the bike itself. I'll probably spend another £50 on metal and bearings this weekend and that should be everything excluding extra batteries (or extra speed controllers if i bugger this one up). With the cheapest eBikes costing £500 new it's still cheaper, but not amazingly so.
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One of each of those batteries costs £35 (although maybe they'll rob me with delivery charges). I suppose it's not too much to take a risk on, and if it works out I can buy maybe a couple more packs to get more range.
I also need a balance charger. I see this (http://www.ebay.co.uk/itm/IMax-B6-Digital-LCD-Lipo-NiMh-battery-Balance-Charger-UK-Delivery-/351012088107?pt=UK_Sound_Vision_Battery_Chargers&hash=item51b9f3692b) one in alot of videos and the price doesn't seem so bad.
I guess I should buy a better multimeter too since my current very cheap one isn't that reliable.
The costs add up! Usually I try not to think too much about the price of things and get surprised when I suddenly run out of money, but for this project i'm keeping a log of everything I spend. I'm curious to see how much I spend in total (tools n all) so I can compare it to just buying an electric bike. I also suspect if I make a video it'll be the first thing people will want to know.
Stan
I guarantee it will cost you more to build than to buy. It will be more fun to build and you will learn more so that is a big plus.
eBike videos on youtube tend to have real bitter comments. People getting upset that it was based upon a cheap bike, people getting upset that it's cheating and an affront to the purity of cycling, people getting upset that it's too complicated for them to bother building, etc. So i'll be interested to see how a video I'd make would fare.
I wouldn't worry about most of the comments on youtube. When you read them they appear to be coming from kids that aren't even potty trained yet so how can you expect anything better.
Carry on with your build here, I'm going to be sitting by watching. Thanks for showing what you have done to date. :D :D
Cheers :beer:
Don
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Steve that charger you linked to will only charge 6 cells at a time, and charges a whole pack across the output leads (all in series). Your proposed system has 7 cells so it wouldn't work unless you charged the 3 and 4 cell packs individually. That's possible as long as your packs are removable -- in other words each pack attaches individually to your bike with connectors.
The charge rate is 5 amps max, which means with 5000 mah packs they would each take an hour to charge from full discharge. That would mean for your proposed 10 Ah pack, 4 hours to charge (theoretically) by shifting and monitoring the 4 packs around during that time.
The further disadvantage is that this charger doesn't charge each cell in the pack individually. That means you have to balance individual cells periodically, by discharging and recharging them on a special balance connector board -- a pain in the neck. And waste of electricity and time.
Also sometimes these "smart" chargers have a cutoff minimum voltage and will refuse to charge a whole pack if an individual cell gets too low. The pack may not be bad if that one low cell could be charged individually, but the charger is not capable of recognizing this, and can't charge cells individually. People throw away perfectly good battery packs with these types of chargers as a result.
The type of charger I use charges each cell individually. That keeps them balanced automatically without the need to discharge and recharge them periodically. It also can't fail a pack for overall low voltage -- it treats each cell individually.
This type tends to be a "dumb" charger -- without a microprocessor and little or no readout (other than an LED showing when each cell is charged). In other words -- fewer "features" but they do the job better.
I don't know how electronics oriented you are but I can contrast the two types of chargers as:
Type 1 has a single voltage regulator attached to a single microprocessor. It charges across the whole pack. It needs a complex internal program for guessing the state of cells in a battery pack. It needs multiple adapter connectors and leads for attaching to different brands and sizes of manufacturer's connectors used on the main battery pack power lead. It also needs a balancing connector board. All these advertised leads and boards look like added features -- but they're really just unfortunate needed complexity due to the way it charges.
Type 2 has multiple voltage regulator circuits -- one for each battery cell -- each one is treated individually. It's dumb It doesn't guess anything. It also charges across a different battery connector, called the "balance connector" which is standardized across almost all battery manufacturers. It therefore doesn't come with a bunch of adapter battery leads or a balance board. It doesn't need them.
I'll look into chargers tonight and see if I can find something reasonable that would work better -- bottom line is, yes you can use that charger you linked to, but you will need to spend a lot of time and attention shifting and monitoring battery packs, and it may refuse to charge a good pack at some point.
re. meters: For a bike I would personally be tempted to just use cheap universal automotive type analog meters.
However there are now some nice Chinese LED digital readouts for V and A -- I got one recently. And with a 100A shunt resistor (usually purchased separately) they would work in the range you will be using. These are really components, not cased meters.
Personally I find digital readouts less good as a warning device than an analog pointer, and the automotive type are cased and ready to go.
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I guarantee it will cost you more to build than to buy. It will be more fun to build and you will learn more so that is a big plus.
Oh yeah i'm definitely enjoying myself and learning stuff - but I also enjoy totally over-thinking videos!
I'm mostly copying Matthias Wandel's style of videos, but I find the types of comments I get pretty interesting. Especially the ones that get upset about the price or effort it takes to build a thing compared to buying it. So I thought I might try pre-emptively address that kind of response in an electric bike video and see how (or if) people react.
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Steve that charger you linked to will only charge 6 cells at a time, and charges a whole pack across the output leads (all in series). Your proposed system has 7 cells so it wouldn't work unless you charged the 3 and 4 cell packs individually. That's possible as long as your packs are removable -- in other words each pack attaches individually to your bike with connectors.
That's a shame. It'll hopefully get me started for testing the motor though.
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Hmm after looking at specs of about 5 different chargers, it looks like the one you linked is a sheep in wolf's clothing.
The digital display and bunch of cords makes it look like the "smart" type 1, but I think it may actually combine type 1 and 2.
I think it can charge individual cells through the balance connectors on the side of the main unit, but includes cords to charge across the pack, and cords to use an auto battery for charging Lipos as a power source.
If so that's a good deal. The only drawback is that it doesn't charge 7 cells. So you will have to charge your 4 battery packs individually.
If this is a combo type 1 and 2 charger -- I don't see anything better for the price range.
There might a way to charge the two 3S packs together (using a made up wiring harness) reducing charge time by an hour.
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Hi
Just reading this thread and noticed the picture of the motor working on the side of the wheel. When I was in holland I noticed some bikes with a small IC engine which was driving the top of the wheel (front wheel). These appear to be sprung loaded to bear vertically down on the tyre which gives a high friction drive. This all but eliminates any problem of rim misalignment. Just a thought if you haven't considered it.
Best Regards
picclock
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Hi
Just reading this thread and noticed the picture of the motor working on the side of the wheel. When I was in holland I noticed some bikes with a small IC engine which was driving the top of the wheel (front wheel). These appear to be sprung loaded to bear vertically down on the tyre which gives a high friction drive. This all but eliminates any problem of rim misalignment. Just a thought if you haven't considered it.
Best Regards
picclock
Thanks for the suggestion. I've seen a few of that type around but I don't really like the look of them. Some people have used sandpaper to try and get a grip and it just seems like it'd cause alot of wear to the tyre, and wreck them if the wheel ever stalled and the motor kept spinning.
Plus, secretly, I also want to try doing something that I haven't seen done before (even if there's a good reason why nobody's tried it this way before!).
As an update, the batteries and other stuff all arrived. I'm now ordering some new connectors (EC3) for the battery since the ones that come with them from hobbyking are some weird genderless ones, and i'm having visions of accidentally plugging them together when fumbling with 12 or more identical connectors. So i'm holding off testing the motor and controller for now. I also need to buy an ammeter and volt meter, or at least read up on how shunts actually work so I can use the multimeter I bought outside of its 10 amps max.
So i've been doing some more metal work and I'm caught in one of those... chains. Where I want to turn down some forstner bits to drill press fit holes for the bearings in aluminium (forstner bits drill aluminium surprisingly well, although i'm making sure to hold it down securely since there's probably a big risk of them grabbing the work piece). But my lathe cant produce a finish worth a damn any more, and I don't want to risk trying to turn the relatively tough forstner bit steel with it as is. So i've decided to give it a long overdue tune up. But that's requiring the delivery of some shim stock. It's a chain of jobs I can't get started on until that one delivery arrives.
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Steve, I know just how you feel!
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Well, forstner bits can drill aluminium it's tough going.
I'd also made the 19mm drill and hole about a quarter millimeter too small. And while the 24mm bearing did press in (using a bench vise) it ended up seizing up despite machining a pressing die to only push the outer race. It's gonna be tough getting that back out.
I think i'm gonna have to approach this different. I might try using my duff 4 jaw chuck as a face plate, the chuck jaw channels would probably work as T slots.
Alternately I could order some reamers of the right size. How do reamers fare with loose setups, like a drill press with a millimeters play?
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I don't really know what you're trying to do, Steve. Any pictures to make it clearer? How thick material, how large the piece, how big the hole?
To speak just generally, for close and/or odd sizes, boring is my favored method for large enough holes in thick enough material to be held in the lathe.
I have made odd size special purpose drills upon occasion, and have also made simple reamers using drill rod (silver steel) with a flat ground at an angle diagonally at one end. But again, hard to tell what you're doing.
Usually boring works best.
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Here's the plate with the stuck bearing. I did think a little ahead and drilled two small holes into the step so I'd hopefully have an easier time trying to get the bearing back out. It's just very tight! I'm thinking about removing the inner race and trying to crack the outer one, but i'm a little worried about messing up the soft metal surrounding.
(http://iforce.co.nz/i/f4w0xlvb.stt.jpg)
Here's the chuck. It's far out of square unfortunately, and I don't know if I could be bothered to spend time carefully shimming the plate if I held it in the jaws, so I figured it'd be easier to just turn it into a real fat faceplate. M8 nuts would fit alright down the channel if not for the scrolls.
(http://iforce.co.nz/i/20ljpsk4.xe1.jpg)
The scrolls are held in by pressed in yokes, which is apparently a common design for 4 jaw chucks and they're supposed to press back out. But I figured it'd be easier to drill and tape a hole in the backs of them, and use a screw to pull them out. Unless they're made from some super hard steel, in which case I'll have to make some sort of forked punch to get them out.
(http://iforce.co.nz/i/oentgz0l.5jv.jpg)
I was really thinking about boring the plates on the lathe to begin with, but I was curious to see if the forstner bit idea would work (which it almost did! I guess I just overdid it shaving the forstner bits down on the lathe).
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For removing the bearing, you might try putting the plate in the freezer overnight, then using a propane torch to heat the aluminum plate around the bearing while pressing it out.
Steve I don't know how much material you have available, and I know money is tight, but if you could hold something else in the chuck, with holes tapped into it to match holes in the part you want to bore, you could first mount that piece and face it square, then bolt your part to it -- it is now square, and then bore your holes. Think of it as a temporarry faceplate.
My first faceplate in my homemade lathe was just a piece of 1/2" pipe screwed into a pipe flange. I mounted that, turned the face of the pipe flange square. Then I screwed to that a 7" dia 3/4" plywood disk, faced that.
Then I mounted my actual rough cast 7" aluminum faceplate blank to that, and faced it, both sides, after turning it around.
Then I bored it and had myself a true aluminum faceplate which replaced the temporary rig with drill rod for an arbor.
Then I trued the edge of the new faceplate did a minor cleanup of the face, and all was well.
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We're babysitting a baby tonight so I couldn't really try whacking the yokes out, so I just used the 4 jaw chuck as is.
And it worked pretty well! Took a bit more setting up but gentle bumps from a hammer got it perpendicular to the lathe. I figure it's going to be more accurate than the forstner bits on a drill press would've been anyways.
It was maybe still a little on the tight side but I pressed the bearing in no problem. Being an idiot I forgot to first machine a bore gauge to check how close I was to getting a good fit, so I just took light passes till it felt close.
I guess I should've done this in the first place.
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For removing the bearing, you might try putting the plate in the freezer overnight, then using a propane torch to heat the aluminum plate around the bearing while pressing it out.
This got the bearing out no problem, thanks for the suggestion!
In other news, turns out my lathe tailstock was pretty much perfectly aligned by default, which was a nice surprise after it seemed nothing else was. I'm now turning a new motor shaft (to fit the gear) between centers.
Had a stupid accident though. To get half-decent footage of the lathe i've been standing the tripod on top of the table and using a step ladder to reach it like in the photo below.
(http://iforce.co.nz/i/p4x4lw5d.c2y.jpg)
No prizes for guessing what happened. Thankfully the camera is still intact and doesn't seem to have sustained any damage. I was recording when it fell too, and had the lense extended far out to focus right in on the workpiece. I guess all the bulk from the telescope mounting (it's really a telescope tripod!) hit the ground before the lense did and saved it.
I've been thinking of constructing a 'sky hook' similar to doubleboost's for a while, so I guess after this I should really stop putting it off.
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Maybe a pipe clamp between joists would work as a temporary support bar for your sky hook.
If you had an extra pipe clamp slide, you could slide and lock that in between the other two ends, and attach a drop rod for the camera to that.
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Freezers are handy things. If you ever need to drill rubber cleanly -- like a rubber stopper, freeze it first.
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Got a bit done today. Leveled the lathe first, or got it more level than it was, which helped reduce the taper on the turned part.
Then I made a camera boom similar to doubleboost's except... junkier. I'm still working out the problems.
(http://iforce.co.nz/i/nqszs1dx.1vk.jpg)
But it still helped get some good angles for recording.
(http://iforce.co.nz/i/oflq5shm.tyn.png)
Finished the motor shaft after that. It's probably the most accurate thing i've produced yet, but that's not saying much.
(http://iforce.co.nz/i/himvcagh.tqc.jpg)
Y'know I trapped my finger every single time I put the motor together. I was trying to prevent the thing from snapping closed when the rotors got near the magnets, but there's really nowhere good to hold on to and those magnets are helluva strong. No blood blisters though fortunately, but it still hurt!
(http://iforce.co.nz/i/krnkonga.ihl.png)
To truly finish the shaft I need to put a keyway in for the gear. But, lacking a mill, i'm thinking about just carefully drilling a hole in and using a dowel pin to spline the gear to the shaft.
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A pin radially through the shaft would weaken it quite a bit.
What about drilling the shaft axially with the gear mounted at the join line, to accept a solid round pin? That would act like a square key, only round. Maybe a drop of Loctite to hold it together while drilling. Center punch on the line, mount it solidly in a drill press, and step drill to final size.
-or-
Can you mount a woodruff cutter in your lathe, and mount the shaft in the tool holder at the right height, to cut a square groove in it?
-or-
If no woodruff cutter -- make something -- even a simple small fly cutter, and feed lightly?
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I have sometimes seen people use their lathe like a shaper, with the part held in the chuck and the tool sideways, and cutting by moving the apron back and forth with the spindle locked. I just figure it'd be awkward to make a kind of 'blind groove' that way. One that doesn't run all the way along the bar to one side.
My concern with the pinned shaft was the pin being more liable to shear than a keyway, but it couldn't be any worse than a set screw. The hole would only have to be drilled as deep as a regular keyway would too, so I don't see how that'd risk weakening the shaft any more than a keyway would.
Thinking about it, I might be able to do the shaper thing by first drilling a hole and using that to start the cut in.
With the part held in the toolpost and a cutter in the chuck, I could probably get away with using a regular slot drill with the part held in line with the cross-slide. The only problem is that i'd have to buy a slot drill!
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You could make a tool to cut a slot using a bit of silver steel - or even a broken drill bit resharpened to give a flat end.
Russell
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Steve a cross pin is far more likely to shear than a round key -- think of the cross sections!
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Steve a cross pin is far more likely to shear than a round key -- think of the cross sections!
Would there be a risk of a round keyway 'jacking' out and putting radial pressure on the gear? The keyway in the smaller gear is cut relatively close to the edge and id be worried about it cracking.
The bigger complication though is that there's quite a bit of shaft beyond where i'd want the keyway to be, since a bearing supports the shaft on the end opposite to the motor, which would make it hard to drill a hole parallel to the keyway.
(http://iforce.co.nz/i/wyc5nc25.gco.jpg)
I still think compared to a set screw a pin would be adequate though.
You could make a tool to cut a slot using a bit of silver steel - or even a broken drill bit resharpened to give a flat end.
Russell
I've only got 8mm silver steel on hand unfortunately, too small to make an effective cutter. I'm thinking now that it'd be worth giving the shaper idea a go, drilling a blind hole in the shaft to give a place to start the cut.
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t=4m20s
Heres a video demonstrating the keyway thing. Shouldn't be too hard to grind a cutter to do this. I could just use a parting tool i've already got ground too and make multiple cuts. Hopefully the 4 way toolpost on my lathe will give me enough room.
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Steve, I didn't realize the gear already had a square key slot.
Seems best to mill the shaft to match then.
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Steve, you don't have to use the scraper method on the shaft, if you have a boring bar (as in the video).
You can mount the boring bar in the chuck as a fly cutter, and the shaft to be milled in the tool holder, and mill it.
The boring bar is just a one tooth woodruff cutter.
Lathe in reverse so you aren't climb milling.
Very light cuts and slow feed. Try on a practice piece first.
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Tragically I don't have a boring bar, i've never had to bore anything too big and deep yet. Plus I feel a fly cutter would make a pretty wide 'scoop' that would remove material from where i'd rather keep it.
I appreciate the suggestions though, but I feel the shaper thing would work best with what I have available right now.
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Well it will be cool to see you do it that way! :coffee:
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We did the shaper thing in school way back when on a external thread for jackstands it worked fine on a whole keyway, I would suggest a hole drilled at the start and end of the keyway otherwise the end will be a bitch to clean up the chips have no chance of breaking off clean if you don't. How hard is the shaft?
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We did the shaper thing in school way back when on a external thread for jackstands it worked fine on a whole keyway, I would suggest a hole drilled at the start and end of the keyway otherwise the end will be a bitch to clean up the chips have no chance of breaking off clean if you don't. How hard is the shaft?
It's just EN1A steel. I've had trouble with silver steel fatiguing in the past so I thought i'd just try a more regular old steel for this one.
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Alright! The shaper thing kind of worked.
(http://iforce.co.nz/i/e320rulw.dnu.jpg)
There were plenty of problems with the method though. For starters, the toolbit was digging in due to the backlash on the cross slide, which made the part slip in the chuck jaws a few times (it was held in without any shims to protect the finish since I find that tends to muck up the alignment). I had to use a 1mm thick tool shimmed to various heights to cut the full width.
The two relief holes I drilled were also kind of small. I figured i'd need to drill holes wider than the slot, but I didn't drill them wide enough. This made it hard to get the cut started and the slot ended up being a slope.
(http://iforce.co.nz/i/vttuzazz.xsi.jpg)
(http://iforce.co.nz/i/ldcxgrx4.h03.jpg)
The results were messy but they seem to work. The key was filed from a round silver steel bar. It's pretty hard as is, and I'm not sure if it'd be worth trying to harden it further. The slot I cut was pretty shallow but hopefully it'll be enough. Can't be much worse than a pin would've been!
(http://iforce.co.nz/i/z4elqzke.2kn.jpg)
I also built the world's laziest spindle lock to keep the spindle from rotating. It works terribly but it was enough to keep the chuck steady during this.
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Keystock is usually soft -- comes in a 12" long stick at most hardware stores here, and you cut it to length with a hacksaw and file the ends smooth and chamfer corners. Usually you'd rather damage the key than the shaft if it shears.
You can always replace a key. Not so a shaft.
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Ah. I was imagining you'd want it hard so that it's easier to get the gear off, but I guess protecting the spindle makes more sense. At least it won't be too hard to remake the shaft if it does shear.
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Ain't it typical for a dropped item to bounce right into the darkest and most cluttered corner of any workshop. Luckily it was just the keyway, but I guess i'll order some keystock for making a new one.
(http://iforce.co.nz/i/enqpxei3.02f.jpg)
I got one of the arms mostly assembled now, and it's a real goofy looking thing, but i'm glad things aren't too misaligned that it doesn't fit together. I'm still not too certain if it's even going to work over all though. The contact wheel will be about 50mm diameter maximum, and that's not going to have alot of surface to contact the smooth metal of the wheel's rim. I don't want to have to put too strong a spring on because i'm not so sure how well these bearings will handle the radial force. I guess time will tell though!
I'm waiting on some circlips to be delivered to finish off the gearbox part.
I also had another of those brain farts and cut the plates wrong, so the gear sticks out a bit forward of the front about a millimeter. Any cover i'd make would have to have a recess in it to accommodate that.
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Hey, it's looking just like your drawing. Good work! :thumbup: :clap:
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looking good
You got that keyway right and if that gear is running concentric with a shaft you did really very good job. Keys are those things that look really simple but are easy to use wrongly. I'm resorting more and more on glue and shrink fit :lol:
Pekka
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(http://iforce.co.nz/i/fpz2lrl4.h2p.jpg)
Been busy the last few days but got a bit done. I'm real glad I bought those burrs at the car boot sale, just used one as a sort of 10mm reamer to get the holes in those aluminium lumps to a sliding fit. Aluminium on steel probably isn't a great bearing surface, or great in general, but i'll see how it goes.
Also note that I mucked up with the angle iron and they're not mirror images of each other.
All i've got left on the mechanical side is keywaying the larger gear's shaft, making some bars to connect that forward hole on the box section to the frame (it should be strong enough without a second set of angle iron struts like planned), and making the contact rollers. I'm short on space near the tyre though so i'll have to make them a bit different than planned. I'll probably also want to fully enclose the gearbox at some point to keep doit out.
Also in other news I hit my left ring finger with a hammer about 5 or 6 days ago, and it's not gotten any less sore. I'm starting to wonder if I've broken it but i'll give it a bit longer. I've been thinking about banjos alot lately but it's killing me that I can't actually play one without it hurting!
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Simon, you gotta take it easy on yerself. You're supposed to last a lifetime! Cuts, burns, and hammer blows are no good, man! :poke:
Bike looks great. I don't think those particular alumin(i)um bearing block will produce much friction for the requirement Seems fine to me.
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Got the gearboxes totally complete now with keyways and circlips. Might buy some loctite to stick the bearings in place though.
I'm playing with the electronic side now. Ordered some 60 amp fuses and a fuse holder.
I've had a problem with the ammeter not working (the needle just sort of twitching at the bottom of the scale), but by chance I had a 'spark' occur through what I think was the shunt contacting the wires I had leading from the shunt to the ammeter, although i'm still not sure why i'd get such a big spark (it blew the chrome off the side of the shunt and scorched the desk) from just that, but that's all that could've been touching. So I suppose the insulation on those wires isn't enough, and were shorting out before the current could reach the ammeter. The continuity itself tests fine.
I'm gonna leave testing it any more until the fuses arrive. That spark gave me a fright. But at least the motor and controller seem to be working!
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Simon you've got the equivalent voltage and current capacity of a DC welder. So yes it could produce a healthy spark if you short something!
In fact it's quite possible to make a DC welder from a couple of car batteries hooked in series, a stick holder and a clamp.
A shunt is connected across (parallel to) an ammeter. A shunt and ammeter must always be used with a load that drops the current to the range they are rated for. Don't ever connect them directly to a battery with no load, since the battery can output hundreds of amps, and the shunt and ammeter are pretty much a dead short.
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Bit late but look what i found..
http://www.petrolscooter.co.uk/spare-parts/electric-scooter-hobby-parts.html
Lyn.
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Bit late but look what i found..
http://www.petrolscooter.co.uk/spare-parts/electric-scooter-hobby-parts.html
Lyn.
That's not bad. If this RC speed controller explodes I think i'd be able to replace it with one made for electric bikes on there.
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(http://iforce.co.nz/i/wqcxymvg.g0j.jpg)
Ugly flash photo of current progress.
Cutting that aluminum bar was a chore, and i've got to do it yet once more~
It took a terrible amount of time to then turn the bar down. Alot of it was spent trying to make a tool that could break the aluminium chips since they were getting kind of dangerous (one whipped my face!), which I finally managed. Didn't take any photos of it yet though.
I'm still undecided on how to attach the wheel to the shaft. It's a light press fit as it is. I'm thinking either loctite (the kind you can heat up to release it if needs be), set screws through the thicker part (with the holes covered with the tyre), or a pin through the thinner part. I'm liking the idea of pins the most since it won't require buying anything, and i've learned from experience that grub screws are hard to find (and i'm sick to death of ordering stuff online).
Unfortunately i'm kind of getting to the point where the project doesn't seem so exciting any more. I think my favourite part of any project is the 'solving problems and learning new stuff' part, and the rest sort of feels like going through the motions. That's not to say I wont finish it, it's just i'm thinking about other stuff most of the time (right now I can't stop thinking about turret tailstocks, and how i'd build one without a mill! It's part of the banjo plan).
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It will be pretty exciting to sit in that seat and strapping on that war helmet, shoving off and switching on, though! :poke:
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It will be pretty exciting to sit in that seat and strapping on that war helmet, shoving off and switching on, though! :poke:
Yeah that's true! I could probably have it together for a test ride in a couple of days if I get my act together. Still got to build the whole control side of things before its complete though.
As a side note, I was at the boot sale on Sunday and spotted 4 different big tubs full of laptop batteries. If there's as many next Sunday, I might buy them all. I'd only really given up on the idea of assembling a battery from old laptop cells after finding out they cost a fortune on eBay, but if I can get them cheap enough it might still be preferable to spending more on RC batteries. Plus lithium polymer is kind of frightening!
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(http://iforce.co.nz/i/ovwph1fg.iob.jpg)
No shortage of aluminium chips!
(http://iforce.co.nz/i/jcb1drnd.2b4.jpg)
Here's the tool. It only really works on facing cuts, but it's ideal for hogging out the bulk of the material. It's a fairly deep groove. It might be old hat to some people, but i've been trying to make a tool that can break aluminium chips for ages with no success till now, and it certainly makes life easier.
I also found I could cut the aluminium bar with one of those little TCT blades I got at Aldi a while back, the saw it came with has little power so it tends to stall way before it would risk kicking back, so I could keep rotating the bar in the vise and cutting as deep as I could till it stalled, then rotating the bar and starting again. It's not ideal, and maybe a little bit dangerous, but preferable to spending several hours hacksawing through the thing. A powered hacksaw is still on my list of things to do at some point though.
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(http://iforce.co.nz/i/1j5mnkfd.ypw.jpg)
Got the contact rollers on the arms. All I need to do to test it is to mount a spring and hook up the electronics. Hopefully that fuse box will arrive tomorrow.
(http://iforce.co.nz/i/ioaz0nr2.gkl.jpg)
I also borrowed this brake lever from one of the old bikes rotting in the back yard. I was worried i'd have to make some sort of mechanism to do exactly what this does. I'm also glad this bike came with those little extensions on the handle bars for mounting stuff like this! The idea is that the arms can be released from the wheel like a brake caliper in reverse so I can pedal without working against the motor. Forseeable problems are the heavier motor side not wanting to lift as much as the lighter idler, away from the wheel.
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Thank god the suns setting and it's getting cooler. Today was too hot!
I went shopping for various electronics bits and made a box.
(http://iforce.co.nz/i/qvfk0ucb.uci.jpg)
It's not very discreet but should do for testing! Fuses should be enough to 'monitor' the amperage normally, but i'd like to be able to see what the current draws are when going up hills and stuff at first. I'm not sure if the analog volt meter will be accurate enough to gauge how much power is left. I'm also not sure how well these meters will handle the vibrations from riding.
I've found that one of the pins on the servo tester had melted off, which must've been what caused that spark. Hopefully everything still works since a short like that could have wrecked the speed controller. But that short made me think twice about just taping a big mess of wires onto the handlebars for the sake of testing, and I may as well try and do it properly the first time.
(http://iforce.co.nz/i/d0npn40a.okd.jpg)
I like having a table saw though. I've tried making a box with full miter joints like this in the past with just a circular saw, and it was practically impossible to make it accurate enough. It's rounded over since i'm probably going to paint it all black. The visible gaps are from the poor quality plywood!
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Still following Simon and it's impressive how much you've progressed these last few days. The motor rig looks great on the bike.
Does that ammeter have a shunt in it already? Seems like it might if it is calibrated on the front in amps -- unless the shunt you showed earlier is packaged with it, Or it's spec sheet calls for an external shunt.
Those meters look like the sensitive type rather than the automotive type. I hope they will handle the vibration levels of a bike.
The cause of your short isn't explained but must have hit the servo tester hard to melt a pin. I would guess it is dead. Do you have an R/C servo to test it with as just a servo tester? I believe you were into R/C cars?
Do you know anybody locally who is into R/C who could check your wiring out? Is there an R/C club nearby?
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Still following Simon and it's impressive how much you've progressed these last few days. The motor rig looks great on the bike.
Does that ammeter have a shunt in it already? Seems like it might if it is calibrated on the front in amps -- unless the shunt you showed earlier is packaged with it, Or it's spec sheet calls for an external shunt.
Those meters look like the sensitive type rather than the automotive type. I hope they will handle the vibration levels of a bike.
The cause of your short isn't explained but must have hit the servo tester hard to melt a pin. I would guess it is dead. Do you have an R/C servo to test it with as just a servo tester? I believe you were into R/C cars?
Do you know anybody locally who is into R/C who could check your wiring out? Is there an R/C club nearby?
Yeah the ammeter came with a matching 75mv shunt.
I think my wiring should be fine. I'm no electrical engineer but i've checked the specs of all the cabling and connectors i'm using to make sure it capable of carrying the current and has appropriate insulation. As for the wires going to the right place, I've made a very professional diagram (http://iforce.co.nz/i/uncjtymu.h2b.jpg) to help keep things organised.
I do have some servos but they're buried in my 'big box of useful looking stuff', which itself is currently buried.
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Simon, question -- the battery on the servo tester in your circuit diagram -- does the ESC you purchased have an onboard BEC, and isn't the servo tester powered by that through the ESC connector?
Could that be the cause of your short?
If you use a separate battery for the servo tester, you may need to break the RCVR power connection from the ESC if it has an onboard BEC. Generally receiver power (~5V) is supplied through the red central wire in the ESC connector, and the central pin.
The white or orange wire is usually the control signal, and the brown or black wire is generally the ground.
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Simon, question -- the battery on the servo tester in your circuit diagram -- does the ESC you purchased have an onboard BEC, and isn't the servo tester powered by that through the ESC connector?
Could that be the cause of your short?
If you use a separate battery for the servo tester, you may need to break the RCVR power connection from the ESC if it has an onboard BEC. Generally receiver power (~5V) is supplied through the red central wire in the ESC connector, and the central pin.
The white or orange wire is usually the control signal, and the brown or black wire is generally the ground.
That could be it. I cant find anything that says it has onboard BEC, and the sheet that came with it is generic to a whole range of ESCs. But looking at that picture at the top of page 2, there is a group of 3 wires leading out of the ESC.
I'd prefer to feed the servo tester with external power so I suppose i'll break that red wire.
So far today i've been cable-tying stuff onto the half finished carry rack to have a go at testing the bike. But i'm still fussing about how to build a throttle. I'm not so sure if I want to be sitting on the thing trying to control the speed with a loose potentiometer. The pot inside of the servo tester reads 0-10kohm, so i'm gonna try using a 0-100kohm pot i've got since the throttle lever wont be able to go through the pot's full motion. Although I think I once read that potentiometers are often used instead of rheostats since they're kind of two-way. I just hope that using a higher value potentiometer won't muck up the servo tester's function.
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Check out the servo tester's function first with the original pot.
Re. breaking the red (middle) wire in the 3 wire ESC lead -- you can do this non-destructively by pressing down with a paper clip wire on the square tab in the connector to release the pin and pulling the pin with attached wire out.
ps. the BEC is the battery eliminator circuit. It is meant to output 5 V to the receiver to power it in an R/C vehicle using the same batteries that power the motor (usually much higher voltage). It is often powered by a linear voltage regulator like a 7805 IC. At least in cheaper versions.
Usually the onboard microprocessor is programmed to cut the motor when battery voltage drops to a pre-set low, but to continue to supply the receiver with current through the BEC so a plane can be landed, even with the power off.
ESC's vary in function. Most can be programmed for some of their functions.
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ESC's vary in function. Most can be programmed for some of their functions.
You will need to ensure that the brake facility is disabled........otherwise you might find the rear wheel will not freewheel...... :lol:
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True John! Though in my experience default is always brake off, out of the box. I also haven't found the brake to be very effective in real life with non-folding props. Slows them some, but it is far from a hard stop.
Still, other features may need programming after trial. Timing for instance.
Simon --bad timing is usually evidenced by a ugly sounding squeal on rapid throttle movement at low speed. Sounds mechanical like shot bearings, but isn't. Tipoff is that slow throttle advance (or smaller prop on a plane) doesn't cause the sound. Timing in that case usually can be altered by programming the ESC.
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I'll have to read up on programming ESCs. I didn't even know that was a thing!
It's been horrifically hot today, so i've tried stay out of the garage as much as possible.
So I did a bit more electronics stuff. Soldering fiddly connectors and crimping terminals. Hopefully nothing will come loose and short out.
(http://iforce.co.nz/i/hislxz0u.dk0.jpg)
I found when soldering DIN connectors (and wrecking two) for the commodore 64 that it's best to plug the plug into a socket to prevent the pins from moving when the plastic gets soft from the heat.
(http://iforce.co.nz/i/lfd1n4jx.yj5.jpg)
(http://iforce.co.nz/i/vjoitng5.eet.jpg)
(http://iforce.co.nz/i/0qoqiq1f.x2l.jpg)
I've got no idea on the 'polarity' of these meters but it wont be a hassle to switch the terminals if the needles move the wrong way.
(http://iforce.co.nz/i/4hezsivg.4df.jpg)
Maybe too much photos for such simple work, but I always get a little too excited about soldering. It's quite satisfying!
Edit: Haha, aint that typical. I've been soldering all day without a problem, and then I give myself a nasty burn heating up one of those creme brulee puddings!
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Simon, the way it is usually handled is on a transmitter, the throttle stick is moved in a specified sequence to program in usually six to 12 variables. You listen for tones that the ESC emits in sequence, and then move the throttle stick to select your options. To do this you need to know what that code is. It usually is in the instructions that came with the ESC. Sometimes you have to do a little internet research if the instructions don't include this.
What is the brand of ESC that you bought, and where did you buy it from?
It's fairly likely that your ESC already is set up with usable default values, and you might not have to change anything. But you should have that documentation.
Your potentiometer will act as the throttle stick pot.
Incidentally, don't be surprised if on first trying your motor out for a bench test if the motor doesn't seem to respond. There is a lock-out feature that prevents energizing the motor if the throttle stick (or your pot) isn't set to zero throttle when you connect the ESC to power. You need to move the pot to zero to arm the ESC.
This fact is actually used to do the programming, too. Generally you put the ESC into programming mode by setting the stick to some specified positive position before connecting the ESC to power. The ESC responds by altering its initial musical sequence to let you know it is in programming mode.
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http://www.ebay.co.uk/itm/261313678316
This is the model that I bought. It was cheap enough that I was willing to take the risk.
http://iforce.co.nz/i/pm4llk0z.r00.jpg
This is a scan of all that came with it, in glorious Engrish.
http://www.hobbyking.com/hobbyking/store/__7341__Hobbyking_SS_Series_90_100A_ESC.html
A post on a German forum says 'it looks similar to this' which it does. But that's all I could find from googling around.
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Working on it. It will take some sleuthing for this particular ESC.
First hit:
http://www.rcuniverse.com/forum/brushed-brushless-motors-speed-controls-gear-drives-123/9046787-rc-smart-80-amp-opto-esc-programming.html
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That's great, thanks!
One thing I was wondering about was how i'd deal with not running the batteries flat since I think that can ruin lipos, but it looks like you can program the esc to automatically cut off before that happens.
Also when I first heard about esc programming I was a little worried i'd have to buy some sort of accessory, but it looks like i'll be able to just do it with the regular servo tester/ throttle.
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Simon, yes all ESCs cut out when the battery nears the allowable limit. They often even have two styles of cut-out -- hard and soft. Soft means the engine slows down (to let the pilot know before cutoff that the motor will be cut. The hard cutoff just shuts the motor down.
When you set the programming for the number of lipos you are also setting the cutoff voltage.
Yes you can program an ESC with just tones and the throttle. It can get confusing at first, but once you "get it" it's do-able. I've never bought a programming card, and do all ESC programming "on the beep".
One more reference that might be helpful for programming this ESC, and seems to confirm is the link you gave me to Hobbyking for the "similar" esc.
If you go to that page, toward the bottom you'll see a set of tabs. Click on the FILES tab and you'll see support files for that ESC. The top two files (numbered) are in English and are instructions for programming that ESC. Download those and compare to the link I gave earlier.
Now as for actual settings -- Suggestions:
Set the number of cells in series you will have. Set lipo. Set no brake. You want probably soft start (usually used on helicopters -- a gradual ramp up n speed). Try auto timing. If that doesn't work (loud squeal when you crank the throttle) try soft or lower timing.
But please figure out why you had that short, if you haven't already. Was it really moving a bare lead or pin to contact something accidentally, or was it wiring hookup error. If the former, then things should be better now that wiring is soldered and insulated, etc. But if wiring was wrong, it will happen again (unless it was changed).
It looks pretty definite that your ESC has no on-board BEC. It therefore does not need the center (red) lead going to the servo tester, and absolutely requires a separate battery to drive the servo tester (assuming it still works).
It would be a good idea to test that servo tester somehow separately before trying to drive the ESC and motor from it. Or buy a new servo tester to be sure. They are the least expensive component.
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Few more things, keep battery leads as short as possible. Motor leads can be extended in a pinch in preference. (ESC's don't like long battery leads.)
Wire gauge needs to be sufficient to carry the expected current for the expected distance.
Make sure ESC and batts get good airflow for cooling.
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(http://iforce.co.nz/i/zb23pae4.stl.jpg)
Little bit more soldering and also dug the servos out. The tester still works fine even after the short and butchering it.
I really hope it cools down a bit tomorrow because the last few days have been hell, and I haven't really felt up to doing any serious work in the heat.
Airflow for the ESC I had considered but I was thinking about putting the batteries in a wooden box. Didn't really think too much about them heating up... Maybe i'll make a wooden box with holes in it!
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So when the batteries finally shut off could it not switch to another bank of batteries? And couldn't a arduino handle all that and more?
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Tom it could be handled with a battery switch, or even simpler still, if cells were the same type and capacity, paralleling them for longer duration.
Simon, I get the same way when it's too hot. Small workshop jobs start to seem too complicated to attempt.
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Well it took two seconds for the tyre on the little contact roller to stretch and split. I think I might have to glue the next one down, but even then it'll probably have a short life.
But hey it seems to work. The motor turned, but i'd forgotten to insulate the three connectors between the motor and the speed controller and got a bit of arcing there. It was after that that I noticed the tyre was wrecked.
I'm not sure if glue would even work though. Might have to machine thicker rubber rollers or something.
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Hockey pucks? boat trailer bed rollers? etc.
Like I mentioned earlier, freezing rubber makes it machine or drill easier.
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I glued the next tyre on and it seems to be going okay. But now a new problem; the motor is turning the wrong way! So i'll have to change the ESC settings.
In this heat just going up and down the stairs is killing me. It rained this morning too so the humidity is up.
The ammeter still isn't responding, so I think the whole thing is duff.
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(http://iforce.co.nz/i/bxtp4qua.den.jpg)
Well, I figured the tyres would wear out quickly from slipping but I didn't imagine they'd do this. All the melted galled rubber made the thing bump every time it turned.
For a very short while it was actually moving under its own power, except not too fast since it was still slipping. The rubber is a fairly soft rubber.
(http://iforce.co.nz/i/hzovbvi0.5eb.jpg)
The first test it didn't move at all (but did help a bit going up a hill), so I put on a much stouter spring. It might need a heavier spring yet. Not sure if i'd want to stick with the soft rubber for the sake of gripping or switch for a harder rubber that i'd imagine wont gall up as bad as that as it wears? Or maybe make a thicker tyre that can squash a bit to give more contact?
I'm beginning to wonder if this idea will even work at all though, but i'm not ready to give up yet.
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Well it looks like you've got the motor going in the right direction, now, but usually you don't have to re-program the ESC just to change direction of rotation. Just switch any 2 of the 3 motor wires. Bullet connectors make that easy.
The melting of the tires is probably the result of slip-- and maybe a low melting point compound. Better rubber will help plus the tension should be sufficient to prevent slip. That spring doesn't look like much.
Since other roller motors seem to work on bikes, maybe investigate their rollers.
Sounds like you're close to getting this working! Which is pretty amazing considering it is only the first iteration! Check my sig.... :lol:
Ammeter is essential. Can you get a universal replacement automotive ammeter? Often pretty cheap.
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Well it looks like you've got the motor going in the right direction, now, but usually you don't have to re-program the ESC just to change direction of rotation. Just switch any 2 of the 3 motor wires. Bullet connectors make that easy.
The melting of the tires is probably the result of slip-- and maybe a low melting point compound. Better rubber will help plus the tension should be sufficient to prevent slip.
Since other roller motors seem to work on bikes, maybe investigate their rollers.
Sounds like you're close to getting this working!
Ammeter is essential. Can you get a universal replacement automotive ammeter? Often pretty cheap.
Had no luck finding automotive ammeters cheap, and the thing that puts me off them is that you need to wire them in series I think. To have that ammeter at the front of the bike would be alot of cabling. I might just try ordering another ammeter of this style since they're reasonably cheap. Hopefully a 50amp fuse will be enough to 'monitor' the circuit though, and blow before anything overloads (with the motor rated at 65 amps). I'd still like to see the current draws out of curiosity though.
(http://iforce.co.nz/i/q5v4pfh1.v54.jpg)
(http://iforce.co.nz/i/xyxquv5s.jt4.jpg)
For the wheel I think i'll try something like this. A step and 2 washers holding a solid rubber wheel. The blue part represents threads! Except finding solid rubber like that might be difficult. But it'd be much easier to change the wheels for new ones this way. I hadn't really considered what i'd do about the original wheels wearing out...
I tried rubbing a skateboard wheel against the rim of the bike and found it got a good amount of grip, despite being very hard rubber. It's not my skateboard wheel to use though, but I think I have a set hidden somewhere. Chances are they're buried in that box of useful looking stuff. I imagine skateboard wheel rubber is probably designed to wear away... gracefully.
Also in that one video of a similar motor system, it looked like instead of using strong springs to grip the wheel it used the force of the motors turning to pull them into the wheel and grip. That said, I haven't found a single video of it actually pulling a guy under load.
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I have a feeling we're going to be seeing a video of a motorized bike pulling under load, soon! :thumbup:
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An audible ammeter would be kind of cool -- maybe a tone that rises with amps -- like a metal detector does! Wish I was more of an electronics guy.
Or a remote pickup ammeter -- that way it could be up in front and only the pickup wire going to the back, to keep batt cables short.
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An audible ammeter.....
Or a remote pickup ammeter -- that way it could be up in front and only the pickup wire going to the back, to keep batt cables short.
Could be done using an analog Hall device.....food for thought?
But why make it complicated?
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Wish I was more of an electronics guy.
Same here! I keep thinking that some day i'm going to go all out with electronics, and especially microcontrollers. Seems like there's alot to learn though.
It used to be my main interest as a kid, but I started finding it frustrating to try learn new stuff at some point. It was really hard to find information before the internet. There weren't many good non fiction books in the local libaries. Didn't help when school wouldn't let me take the electronics module and I got stuck sanding lumps of wood they cut for us (which they called Resistant Materials. Fancy words for wood'n'plastic).
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An audible ammeter.....
Or a remote pickup ammeter -- that way it could be up in front and only the pickup wire going to the back, to keep batt cables short.
Could be done using an analog Hall device.....food for thought?
But why make it complicated?
John thanks -- not food for thought for me, because I can't design circuits.
The problem with running long battery wires to an ammeter in a dash panel is that I've read in a few places that ESC's are sensitive to length on those lines. If the batts and ESC are close to the ammeter, then it wouldn't be a problem. Usually the ESC and batts in a model plane are very close.
Do you have any other suggestions?
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John thanks -- not food for thought for me, because I can't design circuits.
The problem with running long battery wires to an ammeter in a dash panel is that I've read in a few places that ESC's are sensitive to length on those lines. If the batts and ESC are close to the ammeter, then it wouldn't be a problem. Usually the ESC and batts in a model plane are very close.
Do you have any other suggestions?
Myself i'm quite happy with putting in a shunt like i'm already doing. I think it's just the ammeter I got is duff. I'm gonna order skateboard wheels today at some time so I may as well order another ammeter from somewhere else.
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You could just wire the shunt in to an op amp circuit to give a direct reading feeding a voltmeter and read off the value as Amps......no worries about long wires then if you need the meter within eyesight.....
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You could just wire the shunt in to an op amp circuit to give a direct reading feeding a voltmeter and read off the value as Amps......no worries about long wires then if you need the meter within eyesight.....
I appreciate the suggestion but this stuff is way beyond my understanding. It'd be a project in itself trying to learn it all!
I ordered another ammeter along with skateboard wheels to give a plain ammeter another shot.
Another thing I could do temporarily is buy some banana plug leads for my multimeter and wire it into where the ammeter would go. I left space on that panel for some multimeter jacks so I could get more accurate readings than the cheap meters would give. I'd need to read up on the maths to figure out how much the reading would drop with a 75mv shunt though.
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Is there any other info with the shunt?
Basically inserting the shunt from ....Ohms law...V=IR,
75mV=I*R, so if the resistance is 75mOhm, a curent of 1 amp will flow....
Whats the range of the ammeter supplied with the shunt?
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Don't forget the shunt resistance should be matched to the meter coil resistance...
You can't just poke any shunt on any MC meter ...
Were they bought as a pair to be used together ??
Dave
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Dave,
Unless I've interpreted this wrongly, the meter is an electronic one with a led display?.....
But as you say the shunt and meter need to be matched for an mc type.....
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Dave,
Unless I've interpreted this wrongly, the meter is an electronic one with a led display?.....
But as you say the shunt and meter need to be matched for an mc type.....
Oops, sorry! Should have read the whole thread ... :palm: was looking at #106 ish ....
My excuse is I've just been stung by a soddin' wasp ... barsteward !!!
Anyway, back under my stone. After I've checked for snakes etc ... :lol:
Dave
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I believe it's a moving coil analog meter, panel type:
(http://iforce.co.nz/i/qvfk0ucb.uci.jpg)
I'm guessing the shunt is wired in series close to the batt and ESC, and that ammeter signal wires parallel the shunt and are brought out to the meter which is located in the box, fwd on the bike? Because in earlier photos the wires in the box to the meter look to be light gauge.
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Hmmmm....I obviously missed that picture when posted......... :scratch:
Ah well, never mind....
Sourcing another meter shouldnt be too difficult as long as the electrical specs are the same to match the shunt......i.e fsd of the meter and coil resistance..........
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And I missed the point that the shunt could be distant from the meter when I was asking about a "remote pickup ammeter" to keep battery/ESC leads short.
:doh:
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Would a capacitor across the meter lines (if long) reduce noise? I think that's the problem with long lines. These ESC's sense RPM via back emf in the motor to adjust timing. The input lines also see large swinging currents and back emf there from long lines can confuse the ESC.
Or I think that's the reasoning.....
Maybe it's not a problem, though since Simon has had it running already....
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Well if it was me,
I'd lengthen the three leads to the motor, keeping them to a minimum( remove the existing leads from the speedo and attach the longer ones, no joints!).
Then place the ammeter shunt in series with one of the battery leads on the esc, the sense lines from the shunt go to the remote meter, and wind both thru a ferrite donut(one or two turns should suffice to reduce the effects of any noise going to the meter), but as it's an analog meter,I think the effects of any noise reaching it will be negligible .....
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Would a capacitor across the meter lines (if long) reduce noise? I think that's the problem with long lines. These ESC's sense RPM via back emf in the motor to adjust timing. The input lines also see large swinging currents and back emf there from long lines can confuse the ESC.
Or I think that's the reasoning.....
Maybe it's not a problem, though since Simon has had it running already....
Currently it's just a temporary setup with components cable tied wherever they'll fit. I'm gonna be building a wooden box to stick the batteries, shunt, and fusebox in (still thinking about how to keep the batteries cool when inside of a box, but I need to try and waterproof this whole thing). But with longer cabling that might become a problem, but i'll worry about that when it happens I guess.
The skateboard wheels arrived today so I took a little break from taking a break and machined stuff up. Didn't have too much of a problem turning the rubber.
(http://iforce.co.nz/i/sbdlxkwd.n0m.jpg)
As you can see, its fairly low. I really mucked up my measurements, but it's not too much of a concern since I can just make a thicker washer on the bottom to move it back up. It's raining over this way though (at least it cooled down!) so i'll probably give it another break before making the new washer.
I'm thinking I might drill 2 more holes on that bar that holds the spring though, and go with two springs. I guess I want the tension to be so much that the contact roller only slips in the event of a complete stall, and the leverage of the arms really reduces the pressure of the spring where it touches the wheel.
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It's been raining here, too, Simon. Can't wait to see your new rig working! :coffee: :coffee:
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It's alive!
(http://iforce.co.nz/i/vyzedl20.cmu.jpg)
(http://iforce.co.nz/i/3rtsfoga.fbq.jpg)
I think it might send me back in time if I can pedal up to 88mph.
Definitely needs some tidying up. I think I do too! It's just typical that the day (or few days) you don't bother to shave you end up bumping into everyone you haven't seen for a few years. People seemed pretty interested in the bike though, despite how silly it currently looks.
I doubled up the springs holding the wheel down. I think I might add a third since there was a bit of slipping, although at this point i'm a little worried about over-loading these bearings. The tyre on the idle wheel got flung off, which says to me that the wheel couldn't spin so freely, perhaps because of the load. The top bearings are 69012, 12mm inside, 24mm outside diameter, which is fairly thin. I might try boring the holes a size bigger to fit a 28mm OD bearing that can take about double the load of the current ones according to the website i'm buying bearings from.
Also with the enormous spring pressure the idea of using a break cable to release the arms from contacting the wheel seems kind of hopeless. Fortunately the motor turns fairly freely when not running, and doesn't cause any noticeable resistance.
Still, i'm quite pleased that it's actually moving now. I'm just a little concerned about how it's going to hold up in the long run. I'll need to tart it up a bit before I can take out down to the cycle path for a stress test though.
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:thumbup: :thumbup: Well done Simon - nice to see a good result :thumbup: :thumbup:
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Here ya go you have your choice of the original Flux Capacitor :D
http://www.oreillyauto.com/site/c/detail/EB00/121G.oap?keyword=121g
Or the upgraded Mr Fusion model :thumbup:
http://www.oreillyauto.com/site/c/detail/EB00/121GMF.oap?keyword=121gmf
Mind you even without it your bike looks not bad
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Very happy for you Simon!! :clap: :clap: :clap: :clap: :clap:
I imagine that it will create interest every time you take it out. :thumbup:
I kinda like the gyro gearloose/mad scientist look with the wiring in the breeze and the batts akimbo, and the test pilot's gaze of serenity. Now that's the way to enjoy life! :med:
Of course I look forward to the spiffy version just as much!
When you have time to give us some current and voltage figures I can help you tune your motor and drive combination to give best and most efficient performance. :smart: But solving the slip problem comes first!
Suggestions for further thought: It's possible to pivot the drive roller outboard and forward of the rim contact point so it draws itself in to the rim when power is applied. This overcentering would probably allow a lighter spring.
Also, I think the idler pulley might not have to be spring loaded at all, rather, overcenter locked in a contact position -- the drive roller will apply pressure to it through the rim anyway. The idler should be able to be unlocked manually. maybe just an overcenter lever control.
Anyway, :thumbup: :bow: :bow: :bow:
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Well this is off topic. I've been waiting for some left hand nuts to arrive through the post so i've been messing with that Atari ST I found at a boot sale.
This audio/video cable is probably the fiddliest soldering job ive ever done.
(http://iforce.co.nz/i/xnse2xcc.bi1.jpg)
Shoved the 13 pin din connector into an eraser to prevent the pins from wandering when the plastic got soft from the soldering heat. The pins didn't have solder cups.
(http://iforce.co.nz/i/sqaeects.2xn.jpg)
There was more space on the scart side, but it was even more of a fiddle making sure every cable went where it was supposed to.
(http://iforce.co.nz/i/pxdf0lp1.shf.jpg)
See if you can spot the typical mistake!
(http://iforce.co.nz/i/nju2yeqd.rze.jpg)
And it works! Well the cable does at least. Unfortunately the floppy disk drive seems to have problems, but hopefully they're the kind I can fix.
I'm not in so much of a hurry to complete the bike at the moment though since it's dependent on if I can get ahold of laptop cells at the next boot sale. Hopefully the weather is good on Sunday and the folk selling old computer junk will turn up. And hopefully they won't expect the same crazy prices laptop batteries sell on ebay for...
Also, am I right in thinking that if I made something like a 7s 3p battery, to balance charge it i'd only need one 8 pin connector, or would I need 3 8 pin connectors for each battery in series?
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Thanks to vtsteam for moving this thread to a more sensible forum, and giving it a better title!
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(http://iforce.co.nz/i/gmtuqrsv.egz.jpg)
(http://iforce.co.nz/i/h2cglpg4.m2v.jpg)
Couple of little things. Started making another box for the batteries and electronics (i'll probably put holes and a fan underneath to try keep the batteries cool), and reassembled the bike after previously making the left handed thread for the left hand side, as well as replacing the thin bearings with some thicker ones that'll hopefully hold up. If they don't i'll probably make a third aluminum plate to support that shaft above the roller.
Funny thing about the handed threads is that I totally screwed them up, and now the nuts on both sides will be able to work themselves loose! Rather than remake the shafts I think i'll just loctite them on, i'll have to check that the loctite I bought is the sort you can heat to release through. It's extremely strong stuff.
I'd like to have gotten more done today but I couldn't do too many noisy things since we're looking after my brother's very cute baby daughter.
Edit: Oh! I just realised I can just switch the idle/ drive arms around to get the threads on the right side.
Edit 2: Now i'm wondering if the idle wheel would work the same as a drive wheel in terms of tightening/ loosening the nut since the wheel will be turning the roller. All this handedness is really confusing! I think i'll just go with loctite.
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Not sure since I don't use it that much, Simon, but I think Loctite can always be loosened with heat, Some loosening types can be broken free with a wrench -- maybe that's what you're thinking of.
The new bike box and rollers look good! :thumbup:
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I'm getting ready to give the bike a real stress test till the batteries fun flat (or something fails!). I've got a theoretical 10 miles with the current batteries but it'll probably wind up way less than that.
(http://iforce.co.nz/i/sylnxkig.4ms.jpg)
Took a good while to get the charger working. For starters, it turns out its a fake clone of the real Imax B6 and risks overcharging the batteries, so i'll need to keep an eye on the voltage with a multimeter as it charges. Kinda frightening with LiPo...
The hard part was finding a power adapter that'd work with it. It can accept 12-18 volts input but all my power adapters were providing up to about 24 volts when they were without a load. I'm no electronics expert, so I might be doing something really silly here, but I ended up wiring a car bulb in parallel with the charger to give about 16 volts when the charger was idle. Then when initiating the charge, I switched off the bulb. Took a few tries to get a charge rate setting that kept the voltage under 18 volts. It's now charging at a rate of 0.7A.
12 minutes later though and the voltage has risen about maybe .01 of a volt. It's currently at 11.53 volts and needs to reach a target of about 12.6 volts so it looks like it's gonna be a long one. This is only one cell of two as well!
In other news, i've still had no luck finding laptop batteries at boot sales. I need to move on to other stuff though so I suppose i'll have to save the batteries for later, whenever I find any.
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Simon, don't run those batteries down more than 3.7 volts per cell -- that's the usual alarm/ESC cutoff voltage of about 1/8 capacity. That works out to about 10.95 volts for a 3 series cell pack. Fully charged would actually be about 12.45 Volts for the same pack, not 12.6.
When you say "one cell of two" I think you mean one battery pack of two, yes? Each battery of yours is, I believe 3 cells, internally..
Why do you say that your charger "clone" will over-charge? I suspect it will work fine, unless you have a definite known reason why it won't.
Your charger is designed to work with an automotive 12V system -- those vary in voltage as the car alternator does vary its output, hence the "range" of 12-18 volts.
AC auto adapters for home use may run high in voltage if the output is open circuit. What matters is the output under load.
How many amp hours are your battery packs in capacity, and how much current can your charger output? -
You should be able to charge at a rate to get a pack fully charged from empty in an hour. Assuming the charger and the adapter can handle the current requirements.
Example:
For 2000 mah lipos, you would set the charge rate at 2000 ma (ie. 2 amps). Assuming your charger is capable of 2 amps, and your AC adapter can handle the input requirements of the charger (usually marked on the charger box or in instructions).
You can also make a high amperage 12V power supply very simply from a used computer power supply -- there are many instructions for doing this on the internet -- just do a search.
I use one of those with my lipo charger.
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The balance charger claims to be able to charge at a rate of up to 5 amps. The battery packs are 5000mAh so am I right in thinking they could handle that 5 amps charge current (assuming I wanted to charge the batteries as quickly as possible. I hear it's generally better for the batteries to charge them slower).
The current is limited by the wall adapter i'm using though. Would a car battery charger work better as a power source for the balance charger? It's probably one of those things I could ask any neighbor to borrow. I might even have one hidden in the garage somewhere! I'll probably have to find and older one without fancy circuitry though since I hear those cause trouble.
As for cell/ battery. I know better but it's a mistake I keep making when i'm not paying attention. The two RC batteries I bought are a 3 cell and a 4 cell. The one currently charging is the 3 cell.
Also, I forgot to actually hit the post button and this has been sitting here for a while. Charged the first battery to 12.45 volts and now i'm starting on the next one. It's getting late though so i'll probably have to save riding the thing till tomorrow.
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I wouldn't endorse the use of a car battery charger as a power unit for your charger.....generally their output is raw dc with no smoothing....not something it will like.....
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Dang. I might look at a PC power supply with a dummy load then. There's a million sketchy half-assed looking guides on the internet about converting them, and that usually puts me off. But as far as I know a PC supply would have no problem delivering 5 amps at 12 volts.
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Yes you can charge a 5000 mah R/C Lipo power pack at 5 amps -- it is in fact the norm.
You need a supply to the charger of more than the output amps though -- the charger isn't 100% efficient.
An 8 amp or better rating on the computer PS would probably be okay.
Basically to convert one the yellow and black wires carry +12V and ground respectively.
Most newer supplies also have a ON-Off switch sensing wire that turns the PS on or off.
On mine it is a green wire in the biggest connector (might be a different color on a different supply) this gets connected to ground (black). I just inserted a hairpin piece of wire in the connector to make that connection. The PS own switch still works to shut it off.
Some people say you also need a dummy load across a red wire (+5V) and ground so the supply can do a good job of regulating -- and to extend longevity. You can use a 6V light bulb.
That 's about it.
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Simon, if you do end up with an old style car battery charger with no regulation then all you need do to keep it's volts in range is to put it across a car battery and draw your charging source from the pair of them.
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......In other news, i've still had no luck finding laptop batteries at boot sales. I need to move on to other stuff though so I suppose i'll have to save the batteries for later, whenever I find any.
Hi Simon,
I must admit I don't think I'd be looking for boot-sale laptop batteries.
Two reasons really - the main one is that batteries that are that far down the chain may well have limited capacity. Most laptop users leave their machines on mains power almost all the time. Susceptibility to 'memory effect' is reducing - but the batteries are likely to have limited usable capacity. Secondly, the management of charging laptop batteries is handled in different and sometimes quite sophisticated ways by the host laptop - so unless you gut the battery for individual cells, you may need the host laptop to charge the battery pack.
Dave
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Hi Simon,
I must admit I don't think I'd be looking for boot-sale laptop batteries.
Two reasons really - the main one is that batteries that are that far down the chain may well have limited capacity. Most laptop users leave their machines on mains power almost all the time. Susceptibility to 'memory effect' is reducing - but the batteries are likely to have limited usable capacity. Secondly, the management of charging laptop batteries is handled in different and sometimes quite sophisticated ways by the host laptop - so unless you gut the battery for individual cells, you may need the host laptop to charge the battery pack.
Dave
I was planning to gut them for the individual cells. I have the idea that the batteries you'd find at boot sales are all broken (otherwise people who've been collecting big boxes of batteries would probably be selling them on eBay for a fortune?), but would only have one or two cells inside that are fully dead. It'll probably be a chore to check every single one to see if it holds a charge though, but if it works out like I hope it'll be fairly cheap compared to RC lipos.
I think a PC supply would have no problem supplying 8 amps either. Modern graphics cards can draw over 250 watts of power at 12 volts, which is about 20 amps. I'll keep that in mind about the sensing wire too.
I found one video where a guy had made a little board with a dummy load and terminals that he could just plug the motherboard connector into, since PC supplies have a habit of failing (quite spectacularly!) and it's nice to easily switch them out. I might go ahead and do something that since I really need some sort of half-decent lab supply, even if it's not limited current. I've also been using the multimeter alot lately and wondering how I ever got by without one, and it's making me tempted to go back and build that 'electronics shelf' for my desk I planned a while ago (but gave up when I realised it'd need 2 boards of plywood and probably cost a small fortune to make as a result).
Kinda wished I approached the electronics guy at the university chem department when I was still there and asked if he had any old oscilloscopes he wanted rid of. I just never got around to it.
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PC supplies are always labeled with their output voltages and capacities. They all vary. You want to check the spec on the supply for the +12 V line -- that's the one that should be 8 amps. It's easy to find supplies with tons of current capacity on the 5 volt line, but the 12V line is usually a lot less.
I don't favor the laptop batts either I've had too many go bad, and operating on them isn't simple. They will also likely be a mix of different cell types and capacities -- that's going to be hard to match up and figure out how to charge.
Not saying it can't be done -- just, might not work out well -- I just don't know and haven't tried it.
A lot of people swear by A123 batts or LiFe these days because of their safety record. Some people dissect electric drill battery packs and extract the cells. I haven't done that ether. Those cells have a different voltage than Lipos do, so I think you need more of them -- not sure.
Safety: you should charge lipos in a Lipo sack or bag -- these aren't expensive, and are fireproof. If you charge for only an hour, you can stay in attendance -- which is also important for safety. I've never had a problem in 3 years of flying, and don't know anybody else who has in my flying club either.
The main cause of lipo fires is setting the charge rate for a much larger battery pack, and then charging a smaller one at the same amperage without changing it to reflect the smaller battery. I've actually had a Nicad (Nimh actually) melt a plane's nose when being charged, so I don't think any battery is entirely safe. But almost always these things are due to human error, rather than a spontaneous problem. That can happen very rarely, but an appliance or aging house wiring can cause a fire spontaneously, too. For most people ( and here are millions flying R/C) there aren't any problems, other than "puffing" a cell because they flew too long without re-charging. That means one cell in a pack, usually gets gassy and the pack puffs up slightly. If that happens, time to dispose of it.
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That's interesting about a LiPo sack/ bag. I was thinking about putting the battery in the steel crucible to hopefully keep any fire contained. As far as I know, water would just react even more with the battery.
I did see a thing a few days ago where a guy had bought a whole bunch of tool batteries since the company had changed the design or something and was getting rid of old stock. But aside from getting lucky like that, tool batteries seem awfully expensive.
I think by the end of the day there's probably not any reliable way to get ahold of cheap batteries. If it was that easy, everyone would do it!
But I think for now i'll just charge these two cells and see how well the bike works. If it breaks or gives me any more problems I might just put the project on hold, since I really don't have any more time for it. I didn't think it'd take this long and I need to tidy stuff away to make space for the banjo plan, since that might actually make some money if it works out.
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Hi Simon
I have repaired lots of cordlees drill batteries , and it is usualy the first one or two cells on the posative terminal that die ,charge it and iff the pack won't hold a charge the rest will just test back from the posative back, a tip is cut the connecting strip in the centre and solder your wire to the tag , and the heat won't kill the cell .
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(http://iforce.co.nz/i/iszwrhwj.0ts.jpg)
Charging at 3.2 amps now. I set it to 4 though so I think maybe I might need to connect more than just the motherboard header's 12V wires to get more amps, but 3.2 should do for now.
Thanks for the tip about the green on line. I wired that to a switch, and i've got that bulb on one of the 5V wires.
I'll of course have to make a better setup for future though, but right now I just want to try test the bike before it gets dark again. Gonna charge this 4 cell to 16.6 volts to match the 12.45V the 3 cell is at.
Kinda a little nervous with the PSU so close to me though. I had a (really cheap one) explode in the past and it sent sparks up the wall. I want it close to me so that I can feel if things are getting too hot though.
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Whew. Just rode it for about 25 minutes back and forth on part of the cycle track. Decided to head home when the cells got warm. I brought the multimeter along but I forgot what voltage I was actually supposed to be draining the batteries to (was going for 3.7 per cell for storage). Killed myself on the last bit going back up the (very steep) hill. The bike could climb the hill by itself but fairly slowly, but I decided to pedal up it as well since the wheel must've been slipping alot.
The cells are at about 3.6V per cell so I suppose i'll charge them up a bit for storage after they cool.
But yeah, it worked great! I need to disassemble it (hopefully for the last time) to see how well the bearings are holding up. If they're doing okay then I guess I can call the project complete, aside from a few finishing touches.
I also thought it was interesting that on the motor side the whole arm got fairly warm. At first I was worried that it was the bearings overheating, but the one on the opposite side was cool to the touch. I think the heat from the motor was conducting into the whole arm, and the arm was acting like a heat-sink for the motor and keeping it cool!
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Isn't it a great feeling when a plan comes to fruition :clap:
I'm very happy for you - well done :thumbup:
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Good news, everyone! The bearings have held up fine. Can't feel even a tiny bit of grittiness to them.
All I really need to do now is make a throttle (holding a potentiometer isn't just dangerous, it's downright uncomfortable!), which shouldn't be a difficult job. And a cover for the gearbox would probably be a good idea. Then paint everything.
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Great to hear about it Simon! I know there must be a video some time in the future. Can't wait to see it! :clap: :clap: :clap: :beer:
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It always gets confusing making a video when most of the project was fiddling around with stuff to get it to work. I recorded alot of video in the early stages but i've barely recorded anything of the latter stuff.
I should probably set the camera up for the final assembly, so the video doesn't just trail off into an awkward slideshow of 'finishing touches' at the end.
Or I could just pretend i'm a genius and it worked first try!
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The part I want to see is you riding off into the sunset aboard your electric bike!
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Ain't it typical. I had the bike apart ready to paint it and then the long over-due rain arrives.
I've been making the throttle lever instead. Couldn't find any good designs to rip-off on Google, so I ended up taking apart an old RC transmitter to see how that was built inside. It didn't give me any good ideas but it did contain some limited-arc potentiometers, so I quickly drew up this mess and built it.
(http://iforce.co.nz/i/u1rgp2yw.mrz.jpg)
It's ugly, and I probably could've done better, but I didn't want to spend too much time on it.
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Looks good to me.
Did you consider more of a motorcycle style throttle (rotating the grip)?
Seems like it would be a natural match for a potentiometer.
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Just took the bike for another short ride to try record some (the final!) footage. I forgot to put a spanner in the back and the goofy camera mount i'd made started to droop (i've put a huge weight on the front of it, to hopefully dampen the camera from wobbling, since I hate seeing that jiggly footage that most people get in vehicle videos!), and so I couldn't tighten the nuts down. So I started heading back and then the nut on the drive roller came loose!
Had to push the bike back up the hill home. The camera mount also interferes with the rear brake cable and was lightly applying the brakes so that was no fun. I said i'd loctite the nut on but forgot to do it before taking the bike for that earlier successful test ride, and assumed that maybe I had gotten the thread handedness correct. I was wrong!
Anyways it's getting late, its nearly 8:30 and the sun is setting. I guess i'll have to wait till tomorrow to really test it. And hopefully regular retaining compound (loctite 641) will work with the threads.
Oh, in fact, I should probably put a second nut on and jam them together. Dunno why I didn't think of that earlier...
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Looks good to me.
Did you consider more of a motorcycle style throttle (rotating the grip)?
Seems like it would be a natural match for a potentiometer.
I did, but there's not enough space on the handlebars with the grip shifts for the sprockets.
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Well that was an adventure.
Got everything set up and left the house while it was sunny. Had a good ride till it started to rain after about maybe 15 minutes. Rather than head back home like I should've, I decided it looked like it'd only be a light shower and headed on to an old station on the cycle path, to take shelter under a bridge there.
(http://iforce.co.nz/i/b5y4naj3.hez.jpg)
Anyways my sister phones and says she's been locked out, so it's time to head home since the rain was only getting heavier and heavier. It was a full blown thunderstorm at this point and I didn't want to end up riding through mud and deep puddles.
(http://iforce.co.nz/i/5mkf1jw0.ohc.jpg)
I'd brought a whole bunkle of tools in the back box, including some electric tape. So I taped everything up to keep the water out and rode on through the thunderstorm, which was really alot of fun!
(http://iforce.co.nz/i/00tlmtuk.sn2.jpg)
(The video this still is from is really very shakey. I've still got no idea how people manage to take stable footage on vehicles! Maybe that's why people go nuts for those gopro cameras)
Anyways after a bit the motor started to cut out. Turns out when sealing everything i'd neglected to tape up the most important thing, the speed controller. I disconnected it, which was the smart thing to do. Although after pushing the bike for a bit the motor started to really stall despite being disconnected. So I tried reconnecting it, which was the stupid thing to do. The famous blue smoke escaped... had to push the bike about a mile and a half home since I also need to adjust the rear derailleur, since on anything but the lightest and heaviest gear settings makes the chain skip. Also the wet made my jeans shrink!
Here's how it looked after taking the shrink wrap off. A fair bit of water made it in and must've shorted something out.
(http://iforce.co.nz/i/t2ziroba.gcj.jpg)
It's got a hell of a lot of little transistors. There's 3 layers of boards and two of them are transistors.
The only obvious fault I can see is that broken lead on the capacitor. I'd be surprised if it still worked after replacing the capacitor though, but it's probably worth a try.
When I was pushing it the rain eased off. A couple of passing cyclists that'd also gotten caught in the rain took interest in the bike. Turns out one of them used to be an engineer, and said it looked like the kinda thing he used to build. He even asked me if I was an engineer, which was flattering!
Kinda disappointed I didn't get a chance to take some photos of some other interesting landmarks in the area, for the video. There's a few viaducts on the cycle track and some interesting old buildings. Either way I should have enough footage to complete the video.
Looks like I picked the wrong week to quit smoking.
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Simon, we spray a product on ESCs here called Corrosion X for flying with amphibious planes. I wouldn't be surprised if you could fix your ESC. Interesting to see the guts.
Great pix!
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Corrosion X
That sounds good. I was thinking about how i'd keep water out of it while at the same time letting air reach the heatsink to cool it.
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Editing the video now. Took a while to record and process the audio, which is my least favourite job. Ended up with 40 minutes of audio to pick through.
But i've just realised while editing the video that i'd totally neglected to talk about the stuff i'm actually using. Motors, etc. So I suppose i'll have to record a little bit more, as much as I'd rather not...
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Looking forward to the premiere! :clap:
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Alright! Video finally uploaded! Still processing the HD versions though I suppose.
(probably better to watch it on the website itself, since you get a bigger frame)
Yeah thanks for the help, everyone. It's been a long (and weird) project. And apologies vtsteam for getting your name wrong 100 times, even after I tried correct myself in the video!
Bit of a weird video to edit though. I forgot to take alot of photos of the over-all progress, so I hope it isn't too confusing to follow. I didn't even realise that i'd neglected to take a photo of the whole bike until I was editing it.
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Hah, that's weird. at 8m42s the fast forward footage goes in reverse. It's playing forward in the editing software. The sound also cuts out in most of the fast forward clips. I wonder if i'm running out of memory or something, having low memory on my old computer used to cause all kinds of problems with Adobe Premiere.
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Wow, fantastic Simon!!! That really shows the tons of work you put into the bike -- even though I followed along here on the thread, it's amazing to see all of the work in the video.
And the video itself is superb -- as was your helmet one. Production values are really professional. I didn't happen to notice any of the reverse video, or any other problems you mention -- I was too absorbed in the video itself. It's just really fine work all around, and I would think super interesting to just about anybody. You should be proud of your project. Thumbs up!!
:thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :thumbup: :clap: :beer:
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Super video Simon.
:thumbup: :clap: :thumbup: :clap: :thumbup:
Thanks for letting us share your project.
If you're going to add up how much a job costs I suppose it can be better to do it afterwards - if you knew how much it was going to cost before you may have never started!
:beer:
Phil.
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Excellent Video Simon - I've enjoyed the thread and I enjoyed your ride :thumbup:
Just a minor comment: be careful using your bobbin sander for wood followed by metal. The hot sparks from the metal can (and do) ignite the wood dust. Ask me how I know :lol:
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Andrew's warning should be heeded. I had it happen with a belt sander at I school where I worked, I dismantled the guarding in double quick time to get to the fire! Fortunately no harm was done, I don't think that I would have been forgiven if I had burnt the school down, plus I would have been out of a job.
Great video Simon and congratulations on the bike.
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If you're going to add up how much a job costs I suppose it can be better to do it afterwards - if you knew how much it was going to cost before you may have never started!
Yeah, when I first started doing garage stuff I went all out calculating the future price. I'd lump it in with 'planning' in general. If I let myself, i'll plan forever and get sick of the project idea before I even start making it. Now I just get the plan 'good enough' and then dive in.
Plus it's never that accurate since you can't anticipate things not working and needing to change the plan!
Excellent Video Simon - I've enjoyed the thread and I enjoyed your ride :thumbup:
Just a minor comment: be careful using your bobbin sander for wood followed by metal. The hot sparks from the metal can (and do) ignite the wood dust. Ask me how I know :lol:
I did sweep the dust out from inside, but it was just by coincidence. I'd never considered that sparks might be able to ignite the settled dust...
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Simon
That was an excellent project and also an excellent video production and edit I have enjoyed being along for the ride. :D :) :D
Cheers :beer:
Don
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Simon, what a great project, and superb video. You have been rewarded with a motor bicycle you can be proud of due to your efforts.
Well Done
Cheers David
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excellent :)