Priming oilite bushings with a vacuum chamber

[Frank S]

Where it comes to sizing the bushings back in the day when I was rebuilding a lot of very old carburetors, magnetos, distributors and other things for a couple of local antique car clubs I often had to bore and ream out the various bodies to accept bushings then make the bushings since for most things either these components were not manufactured with them installed or no off the shelf replacements existed.
I had a rule of Frank which may or may not been according to Hoyal and almost certainly contrary to sections in the Machinist bible, but since I didn't own one at the time through experimentation I came up with for the OD the bushings in things which were only periodically rotational which did not spin such as the choke and throttle shafts I used the formula of .0001" oversize per .100" hole diameter meaning that a hole of .500 the bushing would be .5005 for 1" it would be 1.001
for rotating shafts with the bush fixed in the bore I used.0002 per .100" diameter
I made installing mandrels to be .0001" per.200" shaft diameter this worked well for me in the smaller less than 1" diameters. For larger bores especially for hardened steel sleeves I used the recommended Timkem bearing engineering press fit calculations the exception being those in the Aluminum transmissions I did which I flanged doubled the interference fit then linear knurled the OD's prior to hardening Since the process of hardening caused the bushings to shrink I adjusted my dimensions accordingly
I always found the use of mandrels for installations to be the up most importance for any bushing install for any type of material
Like I have said previously any machining skills that I have or think I have either real or imagined I learned completely on my own

[olderdan]

Self taught or not Frank you have wealth of experience that most would envy, there are not that many guys left that have the skill or patience to bring a scrap item back to life. It is often easier to remake a part but much more satisfying to repair an original.
Your interference fits are pretty much what I have used.