installing quil on mill drill

[elewayne]

first, thanks so much for hijacking my thread to air your grievances about the board.
But that aside.
I have measured the shaft in several set ups and find it only about one thousandth off. And I'm not sure I'm getting a totally accurate read out.
But I did discover, today, that I can't get the shaft to enter the outside hole, if I put it in that hole first, backwards , if you will. It's just too small. so again, I'm thinking that hole may never have been right from the factory.
It's sort of cold today. So maybe some contraction had occurred and it won't fit now. I'd have to drive it on at this point. It's not going on by hand. and to needs to spin freely. The bushed hole, in front, does go on and spins as it should.
Could I maybe use a brake cylinder hone to clean that hole up a bit?

[John Evans]

Brake cylinder hones do not move much metal. My go to for that would be a short piece of rod with a hacksaw split in one end with a strip of emery cloth wound around it,and walk that around the hole.

[pete]

Since the machine was originally complete and a safe guess it was in working condition then the hole was correct. I'd urge you to think, ask whatever questions are needed, and proceed very cautiously. Once metal is removed it can be 10 times the work to put it back on if you start making mistakes.

[Lewayne]

Thanks for all the reply’s. Just trying to figure out why it’s not working. I was pretty sure the shaft would read bent but I’m just not getting a reading of that. I’ve put it in the lathe several ways and get the same result. I have one other thing I’ll try tomorrow.

[Harold_V]

One thing troubles me and that's that the shaft came out of a hole that you say it won't fit in now. Cast iron doesn't raise much of a burr, but it does displace a little, so I think I'd investigate the condition of the hole, as well as the end of the shaft, looking for any deformation. It takes very little for a snug fitting shaft to not fit in a hole. I suggest this because if a hammer has been used in the disassembly process, it most likely has done some damage. Soft hammers are the order of the day in situations like this, and that excludes the use of brass hammers, which will readily dent steel.

If you can force the shaft in to the hole by hand, and it will twist, do so and give it several turns, then withdraw the shaft so you can see where it's touching the hole. That may disclose a problem area. Also, carefully clean up the end of the shaft before attempting the fit. Chuck it and spin it with some medium abrasive cloth. Don't dwell on it---just give it a quick spin. If there's any deformation, it will likely show up. Remove the deformed area, using a fine file (assuming you find one or more), then try the shaft in the hole again.

If the shaft displays no more than a thou runout when you have it set up in your lathe, I think it's pretty safe to assume that the problem isn't bending. It may not have been any better when it was made.

H

[elewayne]

thanks Harold. The shaft will "not" go back in the hole in the other direction from how its supposed to go. And I have to "force" it through in the right direction. I have only tapped at it with a rubber mallet at any point. It's not that tight. I can force it by rotating back and forth by hand most of the way down.(in the right direction) but that is still way to tight. It's supposed to spin freely, I believe. The hole does have some burrs around its edges. It was never cleaned up well from the factory, (big surprise). I'm going to start today at least cleaning up that hole. I have some inside measurement tools. I'll try to check if the holes are even the same size. I'll check the shaft and clean up the end on that too.
I put the small end of the shaft in my four jaw and trued it up to a thousandth and put my steady rest on the fat part of the shaft leaving the end where the worm gear goes on it sticking out. I trued up the shaft in the steady rest and checked for run out on just that end of the shaft that's in question and still got a good reading. Not bent. and I know that was the most logical answer, the shaft would be bent. I just don't thing it is now.

[Lewayne]

A shot of the assembly

[elewayne]

I did clean up the hole in the worm gear and I really didn't have to do much, and now the hand levers work well and freely. But that only fixed half the problem. Yes. the worm gear did not turn freely on the main cross shaft as it should, now it does, but when I tighten down the two bolts on that white
fine adjustment housing everything locks up again. Now that I can work everything and observe how it works, it appears that the shaft that the with the fine hand wheel mounts on, must be bent, and it appears a good bit. I'll pull it tomorrow and check it out. Earlier I thought it was bad craftsmanship on the wheel base made it not turn straight. but now I think something has hit that wheel, hard.

[Harold_V]

One thing troubles me. I see indications that the major diameter of the gear shows signs of wear, and there shouldn't be any contact with the worm minor diameter. Gears, like threads, should make contact with the flanks. The tightness you discovered may well be because they area not mated properly.

It the shaft is bent, you should be able to see a variable gap between the dial and housing when you rotate the handwheel. If the gap remains constant, the shaft isn't bent, and I can't imagine it being bent inside, although I won't exclude the possibility. The wear marks on the gear are holding my attention right now.

You can verify that the worm is contacting incorrectly by inspecting the worm, looking at the minor diameter. It will show signs of rubbing, just as the gear does.

Assuming you discover that the worm/gear assembly is not properly meshing, unless you don't mind making a huge repair, it may be best if you simply machine some relief where the two are making contact. By relieving the gear just barely below the wear marks, you may find it will work freely, and shouldn't present any problems in operation, as that function is rarely heavily loaded. It would be difficult for you to alter the minor diameter of the worm, so that's not a good idea.

H

[Lewayne]

How do I remove this bearing and shaft for checking. Bearing seems to be pressed in there.

[elewayne]

Yes, saw that too. and suspected it was because the fine adj shaft is bent behind the wheel and dial. that small long shaft sticking up in the photo. The hand wheel does not turn in a flat plane. I have to leave the two bolts on the housing loose for it to turn at all. Then the housing goes up and down a bit as the wheel is turned. that's leading me to believe the shaft is bent on the end.
As soon as I figure out how to remove the shaft from the housing I'll check it.

[Harold_V]

If you have an arbor press at your disposal, and you're able to install a flat, wide piece of metal behind the worm, you may enjoy success by pressing on that piece of metal, which would be blocked at the opposite end. The installed piece of metal will move in an arc (the longer the lever, the better it will perform), which should press the bearings out of the housing. Worth a try. The installed piece should be as thick as can be installed, to prevent bending, and the applied pressure should be as close to the worm as is possible. If a thin piece is required due to lack of clearance, try adding thicker material that extends to the worm.

H