View Full Version : Bushing clearance
I just replaced the arbor on my old Cincinnati #2 horizontal. I touched up the bore for the new running bushing in the overarm with a hone and tightened it up, but it was running a bit hot so I backed it off. It seems to like it somewhat looser than I would prefer. What is the recommended clearance for this bushing?
02-21-2005, 12:06 AM
How big is it and does it run with lube? (Grease or oil?)
2" diameter x 3" long, steel spinning in bronze with 30wt oil for lubrication.
02-21-2005, 12:23 AM
.0015 with constant lube. That's TOTAL clearance! With oil lines (groves) in the bushings, you could go .001 or a pinch less.
02-21-2005, 12:28 AM
Are you sure it is running true? Maybe the slop is needed to compensate for some untrueness.
02-21-2005, 03:45 AM
I have a bearing on my #2 ML that I believe was sold by Jergens(the tooling component company) about 10-12 years ago. It has a zerk fitting, and it doesn't run hot even at 1500. I don't see it in their latest catalog, or on their website. Try setting your clearance with the running bushing off the arbor. What kind of 30 wt. are you using? Try Mobil Vactra #4 way oil.
#30 oil is the recommended lubrication? I'm not sure of the lubrication setup, but since you're aiming for minimal clearance you may do better with thinner oil.
02-21-2005, 06:47 AM
This may sound silly but did you put lube galleries in the bushing? I've rarely come across a new bushing that has one and have to put them in by hand with a pencil grinder. Just don't go out to through the end or you'll have a constant drip to contend with.
02-21-2005, 10:14 AM
As SGW said, you might try a spindle oil, like Mobil Velocite.
The arbor indicates fine. The bushing is the original and has grooves. The 30wt oil might not be correct but that is what had been used and I never noticed a problem before, perhaps I should switch to spindle oil however.
Does anyone know what clearance Cincinnati recommends for the running bushing?
02-21-2005, 10:38 PM
Oh,nooo...just forget bout your old buddy Darin http://bbs.homeshopmachinist.net//rolleyes.gif
Ya,.0015" is pretty much it,white lithium grease first,then straight 30wt synthetic non detergent.After it wears in you can close the tolerance up a little.
If you can hold your hand on the bearing for more than 5 seconds it's okay.
02-22-2005, 10:02 AM
I don't know what Cinci says, but my Kempsmith #2 horizontal calls for 30 wt non-detergent for the arbor bushings. Sounds like a similar setup to yours.