Progress 2G Drill

[mangocrazy]

That sounds like a plan. Perhaps use a longer shanked bolt with the threaded portion cut off so the bolt is good and snug in the drilled hole.

 

[rtbcomp]

Yes. Instead of an electrical interlock maybe the same bolt could be use to lock the gearbox in low gear, using a strong spring to keep it in high when the bolt isn't in place.

 

[rtbcomp]

Managed to get the bearing cover off by using a 5/16 BSW bolt to jack it out.



This exposes the end of the back-gear shaft which also has a hole in it tapped 5/16 BSW, so it should just be a case of extracting the shaft in a similar manner.

It wasn't. The bottom bearing is fast on the shaft, so only managed to shift it about 1/8 inch.

 

[rtbcomp]

Finally got the shaft and gear cluster out, repeated heat/cool cycles freed it up.

This is how I extracted the shaft



This is the gear cluster, top bearing and shaft



and this is the space the gear cluster occupied, the bottom bearing is still in place. It lifted slightly as I withdrew the shaft, but I had to knock it back down again to allow the gears to clear the casting.



Note that the gear cluster can rotate on the shaft and the shaft can rotate in the bearings. Very odd, I would have thought the cluster should have been keyed to the shaft.

 

[MattF]

The old pieces of heavy duty angle iron are worth their weight in gold, aren't they. Btw, the painted/cleaned parts look very nice. Be good to see it complete once you get this bit sorted. It should look very tidy.

 

[rtbcomp]

I'll blast & paint that piece of angle red and call it a special tool. I'm trying to get a parts washer set up so I can degrease the casting, then I'll blast & paint it.

 

[MattF]

I'll blast & paint that piece of angle red and call it a special tool.

Not a stretch of the imagination though. Can't recall the amount of times I've ended up using one of those old bits I keep laying around for something. They seem to be one of the most useful pieces, of what is technically scrap, imaginable.

I'm trying to get a parts washer set up so I can degrease the casting, then I'll blast & paint it.

Would the steam gun not sort the degreasing part out? Not tried steaming myself yet, (that's another future project under a tarpaulin in the garden ), but have heard that steam removes that type of grimy, oily crud quite well.

 

[rtbcomp]

I was a bit disappointed with steam cleaning grease, it just seemed to soften it and push it about a bit. It's one of the small K'archer ones, I used a proper industrial Kismet when I worked on a mink farm and would shift anything, it was diesel fired.

 

[ronan]

Any idea how the other shaft comes out rtbcomp ? Its that one i need to get out.

 

[MattF]

I was a bit disappointed with steam cleaning grease, it just seemed to soften it and push it about a bit. It's one of the small K'archer ones, I used a proper industrial Kismet when I worked on a mink farm and would shift anything, it was diesel fired.

Does it need good pressure to accompany the steam then, for proper cleaning? I have a little thing here which I was planning on trying, but sounds like it may be fairly pointless if that's all they tend to do.

That big thing I've got knocking about is a diesel one. It's a Wickham's though. Handy Dandy, I think the model name is. Might be a similar thing badged up. Not the best of pics, but this is it:

I really ought to avoid going to the yard where that came from. That place is also responsible for my biggest, (both in size and the amount of work needed), retirement project.

 

[rtbcomp]

Any idea how the other shaft comes out rtbcomp ? Its that one i need to get out.

Not yet - watch this space! You need to take the back-gears out first though.

Does it need good pressure to accompany the steam then, for proper cleaning? I have a little thing here which I was planning on trying, but sounds like it may be fairly pointless if that's all they tend to do.

It does really, we used it to clean off the grease from the fur which got onto the wooden nest boxes.

I think mine puts steam out at about 50 psi, it's probably best with a soluble degreaser.

 

[MattF]

It does really, we used it to clean off the grease from the fur which got onto the wooden nest boxes.

I think mine puts steam out at about 50 psi, it's probably best with a soluble degreaser.

Best just to go for a parts degreaser for smallish stuff then. Sounds like it'd be a lot of phaff and muck for little benefit if it's small enough to fit in a vat. On the point of parts degreasers, a simple system I saw a week or two since was merely a vat with an airline powered pump cycling the cleaning fluid through. No other means of agitation. Works quite well, apparently. Might be worth testing some setup along those lines if you're planning on building your own?

 

[rtbcomp]

This is sketch of how the backgear and associated bits and pieces fit together:



The last job is to get the lower bearing out, which is sitting in a blind hole. I used the backgear shaft to do this. I removed the top bearing and pressed the shaft back into place. I then heated the casting around the bearing and the shaft itself. I then doused the actual bearing with a handy aerosol containg a volatile liquid. This caused the bearing to shrink away from the housing and onto the shaft. I then withdrew the shaft & bearing as detailed previously. There is an abutment plate beneath the bearing, but I reckon that can stay put!

I also managed to get the quill shaft out, details to follow.

 

[rtbcomp]

This is how the main shaft fits together.



To release the 64 tooth gear the inner sleeve has to be removed by drifting it downwards. This will take the bottom bearing and its housing with it, leaving the top bearing and the pulley shaft assembly behind.

In my case I had to drift the whole lot upwards as the bearing housing was jammed in the bottom casting.

To do it properly I would gently heat the casting round the bottom bearing assembly and also the top bearing so it doesn't push the pulley shaft down. The inner shaft is free to move inside the pulley shaft.

The key that drives the big gear is a sliding fit in the gear, when removing the shaft just check that the gear can slide up and down to make sure nothing has jammed.

Take care when drifting the inner shaft, it hasn't got very thick walls. A press fitted with a proper mandrel would do a better job.

CORRECTION - The EP 1.06 bearings at the top and bottom of the inner sleeve are 7/8 x 1-7/8 x 3/8, not as shown in the picture

The data in the diagram was taken from the manual, the revised data is from measurements.

 

[mangocrazy]

Excellent technical drawings, Roger. You've clearly done that a few times before. What package are you using?

 

[rtbcomp]

They're just sketches, not to scale or anything. I used CadStd. The Lite version (free) will do those OK, the pro (paid for) version has some extra features, well worth the cost.

I'll be measuring up the bottom gear and doing a scale drawing to see how feasible various repair methods may be.

 

[ronan]

Thanks for the drawing rtb, i hope to get around to doing the work on mine soon, have you found any sources for spares by any chance ?

 

[rtbcomp]

I haven't found a source for bits, I guess any that do crop up will be second hand, and as this problem seems pretty common I think getting a bottom gear in good nick will be well nigh impossible.

The gear itself is hardened, so I guess drilling it and fitting pegs will be out of the question unless it's annealed first and re-hardened afterwards.

I'm taking mine to an engineer to look at later on in the week, so will let you know how I get on.

 

[rtbcomp]

This is the damage to the female half of the clutch



The male half of the clutch has been displaced by about 180 degrees, the key is missing, half of it was found in the oil.



The clutch dog is attached to the gear with 2 grub screws at 180 deg and 90 deg to the keyway. I would have thought one screw holding the key would have been better.

This is a drawing of the clutch, as near to scale as I can get it.

 

[GrahamGKD]

Would it be possible to build up the damaged area with a hard facing rod and then re-grind it I wonder?