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Project Logs / Re: Custom designed Video Light Project
« Last post by spuddevans on Today at 11:58:16 AM »
Well I haven't given up on this (yet  :lol: ), just had a busy month and a lot of prototypes being made/re-made/re-made again......

Finally got some progress to show, here are the latest updates.

So we start off by comparing the PCB we finished in Part 2 with one of my old video lights. I have 3d-printed a bunch of parts to make a Panel-type video light measuring about 240mm high by about 380mm wide. This will contain 6 of the PCB's that were shown in the last video. This video we show the parts and how they fit together.




Then we assemble the parts and glue them together with some slightly-dodgy superglue (took ages to set)




Then it was simply a case of wiring the modules together and then testing it out by comparing the LUX output of it to my previous video lights.




There will be further parts to come, but not for a while, feeling the call to get back to some other projects 1st!!!

Thanks for watching
Tim
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Tools / Re: New (to me) Lathe - Smart & Brown 1024
« Last post by Charles on December 03, 2021, 11:36:08 AM »
So, after much delay, the lathe rebuild is inching forwards again.

New house, new workshop, new baby, and my wife suffering from some health problems have pushed this to the back of the pile. but it's now in the new workshop, with the help of a crane over the house as it is too wide for the alleyway  :doh:

 


Once into the workshop, it was lifted off the trolley with a chain hoist & truck on the steel beam in the roof. slid across the steel beam, and then stuck - cheap Chineseium chain hoist refused to lower! Lifted the lathe of the hoist with a precarious arrangement of jacks, stands, and wooden blocks.

 


Strip and rebuild the hoist, lower the lathe about a foot and the hoist jammed again. so, the lathe is now on blocks, about 200mm off the floor waiting for this weekend and a game of workshop Tetris so that I can get the engine crane behind it and finally move it into place...

Meanwhile, I have managed to make a new glass fibre sump - I counted 18 separate holes in the steel one from 50p size down to pinprick. Much as I need the welding practice, I think I would have spent a very long time getting those watertight.

 

Old corroded tray, biggest hole top left, others scattered evenly about the place.
 

Melamine faced chipboard mold, e-glass / epoxy prepreg, under vacuum and ready for cure
 

finished tray, ill add the baffles and motor mount later when I've decided on which coolant pump to use.
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Tools / Re: Pultra 1750
« Last post by jiihoo on December 02, 2021, 04:06:29 AM »
It's always nice getting more than you expected. I am quite certain that two centimeters of extra center height will come in handy one day.

I looked at the pictures on lathes.co.uk and if yours is anywhere close to the specimens shown there, it will be a very droolworthy machine indeed.

Please post pictures as your restoration progresses!

Cheers,

Jari
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Project Logs / Re: Diy optical pickup for guitar -- is it possible?
« Last post by Boop on December 01, 2021, 01:25:38 PM »
The analog sound synth-y distortion is neat (IMO)!  I hope you do get a chance to check out the links I posted, as in addition to the cool sound you got, I also enjoy the “natural sound” and other options this technology could offer (Along the lines of Hoag, Opik, optical microphones, etc.).

That said, I still dig my Unifuzz that plugs two prongs directly to mains voltage!

https://www.semanticscholar.org/paper/Reflective-Optical-Pickup-For-Violin-Leroy-Fléty/fc7eb46e3be1ccc9a2f62ce9710cfa14f4b5dad6

https://d-nb.info/1020135263/34

https://spie.org/Images/Graphics/Newsroom/Imported-2016/006681/006681_10_fig1.jpg

https://www.optoacoustics.com/industrial/optimic-microphones







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Back under this morning to sort out the parking brake. As I mentioned it's a caliper and pads working on a disk on one of the prop shafts ie a 5th brake, with each wheel having a 'wet brake' internal to the respective axle.

It was just a case of adjusting the 'hold off' of the pads - the hand lever doesn't have a ratchet as you might expect, but is an 'over centre toggle' arrangement. So adjustment is done by ensuring that in the toggled position (ie 'on') the pads firmly grip the disk. It was quite a way off. Then a quick check to make sure that the interlock microswitch was still doing sensible things - it was - and a short drive to the ramp to check that it would now hold the machine - it does  :thumbup:

I'd intended to grease the three prop shafts while I was under there but ran out of enthusiasm. The two driving the axles have three nipples each - one on each universal joint and one on the sliding spline. But oddly, if the book is to be believed, the shaft driving the hydraulic pump, although of the same construction, only has one on the spline - presumably the u/j's are sealed for life? I'll find out when I grease it !

Instead I finally got round to starting to clean out the toolbox. I thought I'd taken pictures of it's utterly disgusting state, but I can't find them. There were various bucket shims and wear bushes, but so much dried up grease that I couldn't detach them from the box until I used a scraper. Anyway today I gave the inside a good brushing down with red diesel and left it to soak, having first scraped and hoovered as much as possible. After a wipe down it's a bit more palatable but still not exactly clean. It'll do for now until things get steam cleaned and painted.
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Project Logs / Re: induction heater
« Last post by shipto on November 30, 2021, 05:58:32 PM »
I'd expect a converter like that, driving the coil directly, would be around 90% efficient and most of the switching losses are in the air cooled FETs. Even if you lost 50% of the resulting HF power in the copper coil, that would still be a fairly modest loss. And given that the power supply is rated at less than 400W, you are not going to challenge the radiator and fan no matter what you do.

Does it say what supply voltage you need to get it up to the claimed 1000W?

Modern processors only take around 30-40W whereas the graphics cards are in the 200-400W region, so I'd hope a water cooling system would be good for 500W or so. That would fit with the tpical PSU rating required these days, given that the output power all ends up as heat.
I think 48volts is the maximum they suggest for running this unit but I did hook my meter to it and the unit was drawing 13 amps which goes down to around 7.5 when the part (a M12 bolt) gets as hot as it will go.
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Tools / Re: Pultra 1750
« Last post by Dell on November 30, 2021, 04:11:14 PM »
Well what a bonus my Pultra 17/50 lathe turned up today and it turns out not to be a17/50 50mm centre but in fact a 17/70 70mm centre so very happy, it looks a bit tatty but the bearings are very smooth and no play so once it’s stripped cleaned and painted it should be good, it even comes with quick close drawbar but I don’t know how that works yet as never used one.  [ Invalid Attachment ]    [ Invalid Attachment ]    [ Invalid Attachment ]    [ Invalid Attachment ]  
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Thanks for the kind words Phil, yes I'm getting there !

Annoyed that I hadn't measured the volume of the oil that I drained from the Slew gear box, and to satisfy this nagging doubt about the 2 litres of hypoid  that I got back in compared with the 4.3 that the book says, it dawned on me I could fill the drain pan with 2 litres of water and compare to the previous photo of the emulsified oil in the same pan. Sure enough what came out was marginally less than what I put back - the book must be wrong!

So hand brake tomorrow. Should be fairly simple, adjust pads to close to the disk, then take up the slack in the cable - this is assuming that the pads aren't too worn. Changing pads is easy (*) but I don't have any to hand.

(* I got used to changing pads on my Project 7 - it was all too easy to drive off with the handbrake on fully, and either rip the pads out or wear them rapidly. This machine has an interlock microswitch. Hand brake on and no motion !

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Good Work Andrew, not really the weather for it, but  when it's done it will be a diamond!
Phil
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So today's job: check  / top up the 'Slew Gear Box' so I need to take the JCB out of the Tractor Shed and put it back in the other way round to give me room to extend and lower the boom and dipper to give access to the slew gearbox filler plug.

As I was moving it across the yard it was sensible to top up the diesel tank while there. It's a bit tight to get it close enough to the Diesel Bowser for the hose to reach and it had to be slightly up the ramp into the workshop to fit.

This revealed another issue to sort - the handbrake wouldn't hold it so needs adjusting !

79 litres later into the 100 litre tank brought it to the top, but I had to put both buckets on the floor to stop it rolling down the slope.

OK back to the tractor shed with the back actor / hoe in the correct position for the next step - check the slew gear box oil.

Drain plug was mighty tight taking a 6 foot scaffold pole on the breaker bar to shift it, and when loose very little condensation water came out. However the oil itself was rather emulsified so I decided to drain and refill with fresh. Left it for ages to end dripping to make sure it was all out.

Now the book - in fact two books (Owner Manual and Workshop Manual) say 4.3 litres but I got barely 2 litres in before it was topped up to the level plug. Not sure whats going on there and suitable questioning post placed on the Vintage JCB Facebook group that has some very knowledgeable members.
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