Recovery from mistake - how to shim one side of bush OD ?

D

dansawyer

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The project was to mill out the holes for the feed shaft of a lathe that were badly worn and then seat a bush with the proper ID. This would hold the feed shaft in alignment. The first part of the project went fine; the first hole was square and centered. However the second went south, about 1/4 of the way through the part moved in the setup and the hole was finishted about 1/8 of an inch out of alignment. (I was not paying proper attention and only realized the problem in time. ) I have machined the hole in proper alignmnet, leaving a 1/8 inch gap for one side of the bush.
What options do I have to 'shim' the gap?
I have read about babbit.
I have thought of taking a material like copper or brass and hammering out a shim to fit and then loctite it in. I am only mildly concerned about having to replace the bushing again. The lathe is 60 years old, it took years of production work to wear the hole.
Thanks in advance. Dan


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Could you fill it with weld or braze and re-machine it?
 
Is is possible to replace that part of the lathe? From your photo it's hard to see how big it is, or if it is part of the main casting.
 
jwmelvin said:
Dam the bottom side (if the gap goes through) and pour in some epoxy.
Click to expand...
I would be inclined to try this approach especially if the bulk bore is sized correctly and the bulk of the bushing bushing is supported in the bore by the casting Devcon marinetex or the like
 
A bit of work...but let me explain.

Get scrap and make a plug same od as the mistake, insure it is snug fit.

Look for thick wall tube or pipe as you only need to fill that space.

Once this new sleeve or slug is made place where it needs to go and mark where to cut the excess.

Now choices..

Drill holes from side to pin it or epoxy?

Determine how it needs to be secured then trim to fit.



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Similar to TQ60. I would first make a slug. I think I would turn the OD to what ever you bored. Than offset and bore the ID the same diameter again. That should give you a press fit plug to fill the gap. I don't know about the epoxy's mentioned but I would use JB weld. Post a picture of your final results.
 
Thank you all. These are all great ideas. My current plan is to start by creating a form the size of the gap from copper, either solid wire or pipe cut to fit. Once the form is near to shape I can solder the parts in place. The purpose of the solder is not to provide strenght but to hold the parts in place. I plan to tap that into place, hopefully a snug fit. I will then exoxy the form in place. I will send updates as I progress.
 
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