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Loctite to hold bearing inner race in place?

Domodude17

Aluminum
Joined
Aug 14, 2017
So I have a Colchester Master Mk.2. It has a flanged shaft that bolts to the side of the headstock, and a pulley with some bearings pressed in slips onto the shaft. The pulley is what takes the power into the headstock. The shaft remains stationary, so the bearing inner race is fixed while the outer race rotates with the pulley.

When I got this lathe, the bearing races were all chewed up and the bearings were toast. I turned down the journal on a different lathe and pressed a sleeve on, and turned that sleeve to a press fit with the ID of the bearing. This caused too little clearance, and the bearings were getting excessively hot. There also wasn't a good way to install the pulley with a press or anything, so the pulley had to be hammered into place. After realizing the journal OD was the issue, I put it back on my other lathe and dusted off a few tenths to get it closer to a slip fit. I succeeded, and the pulley assembly can now slip over the shaft without much fanfare, but the inner race can spin just a tiny bit, and did so when the pulley was driven from the motor.

I REALLY don't want to press that repair sleeve off and turn a new one just a handful of tenths larger. The above work is the culmination of MONTHS of on and off work on this lathe, and I just want to be done with it. I'm just a home shop guy, and i've probably put more work and money into this lathe than I should have so I have been feeling a little disappointed.

I want to just use a bit of loctite on the bearing journal to hold them in place. The issue is that I don't have access to these bearings to apply heat or solvent should I need to remove this pulley in the future. Is there a type of "low strength" loctite that I might still be able to muscle off if needed using a bolt puller arrangement? Alternatively, the bearings are captured in the pulley on both sides by snap rings. I could leave off the snap ring on the righthand side, so that if I need to remove this pulley the pulley itself would slide off, leaving the bearings on the shaft where I can get some heat or solvent on them.

The attached photo shows the arrangement (minus the snap rings) on the left and right sides of the bearings.
 

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    Pulley Arrangement.png
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There are bearing mounting formulations by LocTite, VibraTite and others. They work very well. Clean/degrease thoroughly before using. Not sure about LocTite, but VibraTite has one for 'gap fill' up to .015" and one for 'close fit'.
 
Well, your application pretty much describes what Loctite bearing retainer was made for.

I kinda question your comment that the tighter shaft made the bearings run hot, but I guess that condition is in the past anyway.

I also doubt that hammering the bearing in place is the only method....a pressing device can be applied to almost anything.
 
Green loctite for slip fits is probably what you want. I have used it for applications just like this many times, you can still break the bond with a puller.

I'd loctite it and run it. We all strive for perfection but the real world can be humbling. Sometimes good enough is good enough.
 
“Bearing retaining compound” is the term you need to search. There are various products out there. I won’t recommend any particular one as you have an odd situation there as it pertains to future disassembly.
 
Thanks for the input all. I have some green loctite 620 that i'll probably use, just wanted to confirm if it'd be removable if possible.

Greg, there was a way to get the pulley pressed on using a modified clamp, but one side of the clamp had to press onto the side of a gear in the headstock-not ideal. I do agree that there would be ways to do it though, I just don't have access to them! And modifying the bearing race was just one part down a long list of troubleshooting i've had to do so far!
 
IMO, with enough force you can always get Loctite to break, unless something else breaks first. Green can be pretty strong. The best way to get Loctite joints apart is heat to soften it up.
 
I was given the same model ......the decd owner had rebuilt the bearing in question with hardchrome and ally bushes ....nice work,unfortunately he did not cut oilways in the bushing .......and it seized with a loud bang ....twice ...first time I didnt know what had happened .........so then I cut proper zig zag oilways in the bushing,and opened up the oilway in the casting....No more trouble.
 
IMO, with enough force you can always get Loctite to break, unless something else breaks first. Green can be pretty strong. The best way to get Loctite joints apart is heat to soften it up.
Got to be careful about specifiying Loctite by color. There several greens. I use 680 green retaining compound when I want max holding and most certainly can break parts if no heat is applied for removal.
 
Got to be careful about specifiying Loctite by color. There several greens. I use 680 green retaining compound when I want max holding and most certainly can break parts if no heat is applied for removal.

That was my bad, you're right though. I am just used to reaching in the cabinet and grabbing a color.

Blue = gonna fight you, but it'll come back out.

Red = she ain't come'n back out.

Green = dang it, that was suppose to be a press fit. 😁

I do have red for mating components as well. IIRC, it is high temp up for up to 0.015". Although if something ends up more than about 0.005", I either sleeve it or weld it up.
 
Lots of plus reports here for LocTite to secure the inner bearing races.
My personal expirence is less positive.using the retaining compounds.
I would use a mechanical solution.
A bolt in the free end of the shaft that applies pressure to the faces of the inner races and axially squeeze the bearing pack using spacers will secure the inner races from rotating , and be easy to disassemble.
Cheers Ross
 
Even the super green wont hold in some applications .....I had a slightly slip fit taper roller on an old truck diff ...fit both pinion bearings with green ...rock solid on assembly .......bearings loose in a few hundred miles.
 
The max comprsssive strength of the aneorobic polymer is around 6,000 psi ..........so its obvious its not going to substitute for a hardened chrome nickle gear steel with a compressive of 200,000psi,or a hardened sae 52100 bearing race at 250,000psi..
 
Lots of plus reports here for LocTite to secure the inner bearing races.
My personal expirence is less positive.using the retaining compounds.
I would use a mechanical solution.
A bolt in the free end of the shaft that applies pressure to the faces of the inner races and axially squeeze the bearing pack using spacers will secure the inner races from rotating , and be easy to disassemble.
Cheers Ross
You say that repeatitly And you are the only one so far So elaborate please
It saved me a lot of work over the times though and never failed in applications for its intended use
Peter
 








 
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