Worn Bearings

[woody1Participant @woody1]

I noticed something today about my trusty ml2. When the belts are slack I read .001'' run out, now under tension the run out is .0005''. Can I asume my split bushings are worn guys? I am imagining the tension of the belt is wearing one side of the bushing more than the other?

Cheers.

David.

[woody1Participant @woody1]

[Brian WoodParticipant @brianwood45127]

Hello David,

Belt pull will affect the bearing loading, rather agreebly so it seems in your case, but as to bearing wear that would be a different matter. They are bound to 'ease' more on that side.

A test looking for movement in the mandrel when pulled hard back in a direction opposite to belt loading might be more indicative and then set the bearing nip accordingly to those findings.

Brian.

[Swarf, Mostly!Participant @swarfmostly]

Hi there,

Belt tension isn't the only force on the lathe mandrel. The reaction to the tool cutting force also tends to displace the mandrel in a direction depending on the headstock geometry.

Best regards,

Swarf, Mostly!

[NJHParticipant @njh]

I would think that between 0.0005 and 0.001 run-out on a machine made before 1941 is pretty good!

N

[JohnFParticipant @johnf59703]

Woody, are you saying there is up to 0.001" TIR on your spindle or are you saying there is up to 0.001" play? i.e.pushing and pulling with a clock in the bore and spindle at rest.

Two quite different things!

If it is play in the bearings I would suggest its nothing to worry about — it will be taken up by the lubricating oil when the lathe is running. In Fact if there is no room for the oil you wil have all manner of problems with chatter etc.

Regards John

Edited By JohnF on 07/03/2013 23:48:55

[woody1Participant @woody1]

Evening fellas.

Slow response sorry guys, Garrett turbo re-build, new roof on bungalow anyways back to machine's I am refering to ''play'' I have had a little fiddle after reading the comments about tension and more to note cutting forces. Pushing the spindle ''away'' horizontally toward the countershaft and also up vertically give the play. Guessing A bit of wear. I took a pic when I first had the lathe. As a novice I thought the scoring was a minor issue. I dont suffer with chatter though unless I take really deep cuts (+.005/.010 depending on material). The spindle is smoothe as. I'm learning the limits of the machine. Should I just buy something close and machine a new set guys? I did read simply maching a new set and replacing isn't possible. Seeming I had her for free I'm thinking just spend some cash. I hate made in china guys I really dont want to buy one!

Cheers.

David.

[Ady1Participant @ady1]

Have a go at a replacement set. You may surprise yourself

Do one bearing at a time, only one may need to be replaced to get her how you want

It's all part of the learning process

 

Alternatively, upgrade to a more professional machine, an ML2 was never meant to be anything more than a wee hobby unit

I use an old Drummond/Myford M series

 

(Warning. It's a slippery slope once you start dipping into your wallet)

Edit

On the plus side if you do upgrade you can use it to make bits for the ml2

Edited By Ady1 on 18/03/2013 01:19:49

[Brian WoodParticipant @brianwood45127]

Hello Woody,

I think you are running away with the idea of replacing bearings quite needlessly. You seem hell bent on it.

The picture looked just fine to me, you say the spindle is in good shape so from my ML4 experience of many years ago just adjust the nip on the bearings to take up the trivial wear you have and it should be good for the next 50 years. Nothing more to do, start making things!

If you simply must spend money then buy a decent quality ML7 as a second machine

Brian

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