Progress 2G Drill

[MattF]

Try shredding a bit of candle wax on the shaft/pulley centre and melt it in. Might not make a jot of difference, but... Nothing visibly weird regarding how it's attached? Another method I use on occasion with awkward pulleys, (only generally viable if you have the shaft out of the machine), is laying a piece of angle iron on either side of the pulley, in parallel, with the bottom face supporting the pulley on each side and then the angle iron ends supported on some form of rest, and then generally beat the crap out of the centre shaft, with some soft block material between the hammer and shaft end. Obviously, make sure there's some padding underneath for when the shaft breaks free.

 

[rtbcomp]

I've managed to drift the whole pulley shaft upwards, but the driving member limits on the fibre gear. I need to remove the pulley to get the layshaft out and I need to get the layshaft out to get mainshaft & pulley out!

 

[ronan]

Mines the same - let us know how you remove the wheel! What I have just found is what I thought was the end of the layshaft appears to be a bearing retainer. I've cleaned all the crud away and there is a small grubscrew on the circumference of the disk and the hole in the middle is another grubscrew (5/16 Whit) with a pointed end, possibly thrust adjustment for the layshaft.

I reckon if you screw a longer bolt into that hole it would lift the end cap out. You may have to remove the pulley first, that looks like being another bag of worms!

Another reason the dogs may have worn is that the detent on the gear lever is worn, not allowing the dogs to be fully engaged.

I haven't really looked at the machine in a while as i have been busy with other projects , but i think a few bearings might need replacement too , so i want to do it all in one go and have it done and dusted. Surely these drills were assembled on an assembly line and under time constraints and were designed to be put together in as short a time as possible ? The large gearwheel has to come off somehow.

 

[rtbcomp]

I've managed to drift the whole pulley shaft upwards, but the driving member limits on the fibre gear. I need to remove the pulley to get the layshaft out and I need to get the layshaft out to get mainshaft & pulley out!

I might be kidding myself here.

Look at this photo:



See how the bearing in the bottom right sits proud, and how close the driving dog is to the fibre gear. The mesh between the two bottom gears isn't quite right either. Note there is a piece swarf trapped betwee the bearing and the casting, maybe that's why it's not seated properly.

This photo was taken before I started laying in with hammer and drift.

This all means the driving dog is sitting too high, which could be a cause of jumping out of drive and mashing the driven dogs up.

 

[GrahamGKD]

Note there is a piece swarf trapped betwee the bearing and the casting, maybe that's why it's not seated properly.

Seems very odd - how would a bit of swarf have got in there? Could some bodger have jammed a chip of shimming of something in there because the outer race of the bearing was loose in its recess?

 

[rtbcomp]

It looks like it may have scraped off the bearing when it was being pressed in, perhaps it wasn't quite straight.

To be honest I think the whole thing has had a massive jam. I've found a keyway in the driving dog/pinion interface, trouble is the two halves of the keyway are 90 deg. apart and I found a bit of broken key in the oil! I can't move the driving dog even with the two grubscrews slackened off.

 

[GrahamGKD]

It looks like it may have scraped off the bearing when it was being pressed in, perhaps it wasn't quite straight.

Presumably the bearing is a hardened ball race though - could a bit of swarf peel off that against the casting?

To be honest I think the whole thing has had a massive jam. I've found a keyway in the driving dog/pinion interface, trouble is the two halves of the keyway are 90 deg. apart and I found a bit of broken key in the oil! I can't move the driving dog even with the two grubscrews slackened off.

Could it be that (possibly through things not being aligned properly) both the direct drive and the geared drive were selected together, particularly if someone attempted to change gear with the machine running? You would think that would have mangled the fibre cog though?

 

[rtbcomp]

......
Could it be that (possibly through things not being aligned properly) both the direct drive and the geared drive were selected together, particularly if someone attempted to change gear with the machine running? You would think that would have mangled the fibre cog though?

Hmmmm. If the driving dog came loose whilst in low gear and dropped down it might just catch the top of the driven dog. This could then mangle the key because it would only be partially engaged.

But that wouldn't explain how the driving dog is still in its correct position and jammed solid, unless someone put it back in place and Loctited it.

Incidentally, one of the two grubscrews in the driving dog was lying in the oil too.

 

[MattF]

Restoration is never a simple affair, is it. Without fail, everything looks to be going swimmingly and then something inevitably crops up. That old drill I posted a pic of is similar. Got most of it stripped down and then it came to a complete halt due to the fact that I can't remove owt else until I get the shaft free, but the rear oil cup has had the oil displaced by water at some point, hence the shaft has seized solid in the rear cup.

But that wouldn't explain how the driving dog is still in its correct position and jammed solid, unless someone put it back in place and Loctited it.

If it is Loctite'd or the like, some boiling water should likely crack that bond.

 

[rtbcomp]

everything looks to be going swimmingly - Not got that far yet!

I've just got the pulley to shift, but the grubscrews holding it in place have raised burr. It's a case of get it hot, move a couple of mm let it all cool down and try again.

Would boiling water be hot enough? But difficult to get some in there, but I've got a steam cleaner which nay do the job.

 

[MattF]

everything looks to be going swimmingly - Not got that far yet!

At least you'll know that machine like the back of your hand by the time you're done.

Would boiling water be hot enough? But difficult to get some in there, but I've got a steam cleaner which nay do the job.

It should be. It's only just to penetrate into the joint. Cold water on its own would likely penetrate fine, but it doesn't affect adhesives, epoxies and the like in the same way as hot water does. Steam might work too. Never tried that personally, so let us know how that goes.

 

[rtbcomp]

 

[mangocrazy]

That's looking very good, Roger. Is the cabinet buckling under the strain yet?

 

[rtbcomp]

Not yet! I can't lift the base & column, let alone with all the other bits attached.

 

[rtbcomp]

Got the pulley off at last.

The grubscrews did cause a burr, which in turn gouged out grooves in the pulley, no wonder it was stiff!



This plate is at the top of the layshaft. The hole at the edge (1/4 BSW) appears to be a means of locking the plate in place, the hole in the centre is possibly a means of lubrication or for extracting the plate by means of a bolt (5/16 BSW, same as the pinch bolt on the depth stop assembly)



The larger threaded hole to the left is for the cover latch, it also goes through into the gearbox cavity, so oil will come out of this hole if you turn the drill on its side (and go all over your car).

The large grubscrew to the top of the picture is the oil filler.

 

[MattF]

That definitely explains its reluctance to move. Glad to see its off. Does it look like you should be able to modify that mechanism, now that you can inspect the parts properly?

 

[rtbcomp]

Still not got any closer to the gearbox. Today's mission, should I choose to accept it, is to get that metal disc out.

The burr on the pulley shaft is consistent with the pulley slipping on the shaft, which in turn is consistent with a lock-up as mentioned earlier.

 

[mangocrazy]

I was initially very envious of your ten-speed drill with its fancy gearbox, compared to my humble four-speeder, but now I'm not so sure...

 

[rtbcomp]

I'm having the same thoughts! I could maramalise the bloke who pointed it out to me on Ebay.

I've a sneaky feeling this may end up as a 5 speed, it depends on what it would cost to repair the clutch driven dog and if there's any damage to the driving dog.

Conversion would simply be a matter of replacing the top bearing with a solid bush to connect the pulley shaft straight to the quill shaft, or even just welding the bearing up Such a conversion would be reversible.

 

[rtbcomp]

Plan B

Here's a plan



Replace the upper bearing with two concentric rings, with a hole drilled at their junction. To engage direct drive pop a bolt in the hole, for lower speeds remove the bolt and engage the low gear as normal. This will bypass the clutch and eliminate the backlash.

There would have to be an interlock so the drill can't be started if the bolt is in place and low gear selected. I would envisage a circuit around a microswitch on the gear shift and a housing with a microswitch in it to store the bolt when not in use.