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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.
Project Logs / Re: induction heater
« Last post by Muzzerboy on November 29, 2021, 01:48:57 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.
OK front axle hubs SORTED  :thumbup:

After MANY iterations of driving small amounts either forward or back, then clambering out of the cab and testing the cast in level line on the hubs I managed to get the lines level and test the oil levels one after the other. Near side wasn't too far off only needing about 250 cc but off side took most of a 1 litre bottle.

What would make this job far easier single handed would be one of those spirit levels that bleep at you when horizontal. Not sure if a magnetic version is available  :scratch:

So as far as gear boxes and hypoid oil is concerned that's it apart from the King Post slew gearbox. To do this the machine needs to be on a level surface and the back actor / hoe fully extended horizontal to expose the drain plug and filler / level plugs. Apparently this box accumulates condensation, and the process is to slacken the drain plug to drain the water off, and then tighten it and top up to level, the drain plug having grooves in it to let the water out without fully disengaging it's threads.

I don't quite have enough length in the tractor shed to set the machine up in this configuration so it will have to wait until I've moved a few things about
Project Logs / Re: induction heater
« Last post by PekkaNF on November 28, 2021, 11:17:06 AM »
Nice to hear it works on first try.

Thermal management is pretty straightforward in principle, but in practice if can be challenging.
At last I got the opportunity to crawl under and check the rear axle oil level.

Oil level plug is a 1-5/16" Hex and when I did the front axle I had to jump on my longest breaker bar from the 3/4" square set and even then it was a struggle to unscrew it. (Tapered BSP thread).

So I'd planned all sorts of strategies to get the rear one undone, as being between the wheels and well underneath there was certainly no room for jumping! So - Jack under far end of breaker bar, or make extended 3/4" extension to bring it to 'out from under', or . . . . well what, and to honest this 'or what' had been making me procrastinate.

In the end I thought - 'OK get get under there and try it'. Well legs braced against near side wheel, firm grip, give it your all. No not enough oomph  :bang:

So before dragging out the jacks etc, in one last effort, I got my biggest 'rubber dead blow hammer' and whacked it with all my might. Not easy lying on the floor in a cramped space . . . . but, hey hang on, was that  movement or am I about to skin my knuckles as the socket comes off the hex plug. Another try, and yes, we HAVE movement.

Now bear in mind all I'm doing is checking the level, drip bucket underneath, take it out, and . . . . . it's grossly over filled :lol:

Better over filled than empty, and the fact I'd bought oil in advance matters not a jot as it WILL be used in the future, but that at least is the rear axle and its epicyclic hub gear boxes done  :thumbup:

Not done the front epicylic boxes as I need a 'banksman' to tell me when the level plug is on the horizontal as I drive back and forth. I did try the other day lifting the front on the front shovel so the wheels are off the ground, and turning the wheels by hand, then lowering back to earth, but having the differential between them, as you spin one it turns the other in the opposite direction. Wedging one wheel 'almost' worked, but then the act of lowering back to earth, because of the geometry, turns the wheels. I'll have to be patient and wait for a hapless passing soul to grab  :thumbup:

Project Logs / Re: induction heater
« Last post by shipto on November 28, 2021, 09:47:55 AM »
So because I couldn't wait I hooked it up to test it and I am quite happy I ran it for a good while and the temperature never exceeded 17.2C although its not running at anywhere near full power.
I think that in the future I will get a power supply that will run it better, currently its on a 24volt 15amp and even though I haven't checked the amps its drawing it doesn't seem to be putting the power supply under any strain so I think (size permitting) I will get hold of a 36 or 48 volt supply.
There is very little heat in the caps and only a tad more on the mosfets but its providing enough heat to the part to do what I want it for which is mostly going to be oil blackening parts but if I could get enough heat for hardening parts that would be a bonus.
One thing I will do is rotate the pump so the inlet and outlet are at the top to prevent any air lock in the pump, I should have thought of that before actually.
CNC / Re: Schaublin 125-CNC retrofit to LinuxCNC and Mesa cards.
« Last post by RotarySMP on November 28, 2021, 06:39:49 AM »
I would have expected Schaublin to make the piston alignment pins a closer tolerance.

Project Logs / Re: Diy optical pickup for guitar -- is it possible?
« Last post by sorveltaja on November 27, 2021, 08:08:25 PM »
Joined the group for this post!

Hopefully this thread isnít dead, maybe this can lead to its resurrection.

Played with this a little bit some years ago.  Didnít go much further than hooking up a photo diode and an IR led running into a guitar amp directly, or maybe it was a mixer?  Got output, was very excited, then life ďgot in the wayĒ. 
But I thought Iíd put these here from old Make magazine articles and associated links:
There are more links that Iíll have to find, but this is what I have time to give right now.


Welcome to the forum, Boop. Yeah, it's rather good start to test a setup for an audible output. That's how I did. I don't remember how the progress went, but it's documented in this thread, stage by stage, of how I got the strong hexaphonic fuzz sound that I was after for a long time. Of course that isn't everyone's cup of tea, but hopefully in this thread are some things to consider, when one wishes to experiment with optical pickups. Remember that this project is based on a lot of trial and error testing. When something worked, I used it, and if not, ditched it.   
Project Logs / Re: induction heater
« Last post by shipto on November 27, 2021, 04:42:47 PM »
That cooler might be just a tad to small, also the flow of coolant might be too low. I would check up if that will provide good enough cycle time, if just a tad too 50% would be better, then I would add large enough reservoir of coolant to increase thermal mass and larger pump to pump between reservoir and coil and use up that exisisting system of your PC radiator and small pump to cool the reservoir between heavier use and pauses.
The way I'm thinking at the moment is I might need a stronger pump but as I managed to use it with no cooling at all some cooling must improve things right? If it turns out not to be enough there is room in there for a bigger pump.
Project Logs / Re: induction heater
« Last post by shipto on November 27, 2021, 04:35:04 PM »
So despite the cold and my shed heater packing up I still managed a bit of progress. All the bits are fitted and wired up which wasn't hard.
The output from the temperature controller is wired via the main switch so if it gets too high it will switch off automatically and not start again until its cooled to the lower setting, all pretty standard.
I am still undecided about using the plastic bottle as the header tank because fitting it will be awkward and I might make/Aquire something that fits better.
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