How to 'repair' a worn cast iron bushing ?

D

dansawyer

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Below is a photo of the feed 'shoe' from a 1956 Colchester lathe. The feed rod goes through the 'bush' and drives the gear, partially visable in the center. Over the years the feed rod has gradually worn the bushing surface into this oblong opening. I would like to repair this. The best solution I can think of the to machine out the hole to roughly circular and insert a true brass bushing. Is there a better solution?



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For this job Bronze would be a better solution than brass.
{Yes, I know that is not much better of a solution.}

You should mic the shaft to see how round it <still> is.
 
Yes installing a bushing would be the way- I would epoxy or Loctite rather than a press fit since the wall thickness will be so thin in that one area
-Mark
 
Better yet might be a cast iron bushing it could be fit with zero press fit and retained by screws drilled and tapped at the edge of the bored hole and bushing parallel with the axis.
 
I was going to say a bronze bushing and glue it in with epoxy. A oillite bushing... oil the outsize of the bushing, then epoxy in. it will give you a tight fit and should not come out unless pressed out.
 
Wow, I'd hate to see the feed rod:). It might just be the angle of the photo, but is that around 3/16+ on the radius to bore out? Maybe one could braze some of that, then bore for a bushing and not need to cut away as much cast?
 
Find a local buddy who knows how to stick weld cast iron with Nickel rod. Nickel makes an excellent bearing surface, and after he welds it up, re-machine the hole.
 
I think I would braze the hole ID to about round. Then bore out the hole to a cast iron oil bushing. McMaster Carr shows most bushings are about 1/4" larger then the rod. A 1" dia rod would need a bushing with a 1-1/4" OD. Also, I think I would add extra brass on the outside , space permitting for extra strength.

addertooth said:
Find a local buddy who knows how to stick weld cast iron with Nickel rod. Nickel makes an excellent bearing surface, and after he welds it up, re-machine the hole.
Click to expand...
You can do this too. I like the idea of a bushing that could be replaced in the future because of wear. Either way, you really need to fill up that oblong to round before making the final call.
 
Thank you. I was thinking about the boring out process. The lathe could be operational with a little effort.
The feed rod is just under 3/4 inch. I can use a collet and a 4 jaw chuck at the same time. I woul us a piece of 3/4 as a jig and set it up in the 4 jaw. That would align both ends and support the part for machineing. Are there better way to bore it out?
Thanks, Dan
 
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