# 7x15 mini lathe compound table mod



## moditwell (Apr 1, 2018)

Hi everybody, I am new to this forum.  I thought i wanted to share a mod that has been done by many but this one is totally reversible.  It involves a 12x28x10mm radial and thrust bearing.End results are silky smooth movement like turning the volume control  knob of a high end amplifier.Can't stop turning  the crank handle.Here are some pictures.


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## RM-MN (Apr 1, 2018)

Nice mod!  I did similar to my mini mill "Y" as it had no bearing and the metal to metal contact would gall.


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## moditwell (Apr 9, 2018)

We get what we pay.


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## Wolfie01 (May 11, 2018)

Really nice.


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## dennisa49 (May 11, 2018)

Hello, the mod looks fine. Did you machine the back of the scale?
Thanks, Dennis


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## velocette (May 12, 2018)

HI
Just an observation 
Surely the thrust bearing is not absolutely essential as the 12x28x10mm 2RS bearing with rubber seals is more than capable of doing the job and more suited keeping out metal particles. Can not see how the trust bearing will not pick up debris.

Eric


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## Nick Hulme (May 13, 2018)

velocette said:


> HI
> Just an observation
> Surely the thrust bearing is not absolutely essential as the 12x28x10mm 2RS bearing with rubber seals is more than capable of doing the job and more suited keeping out metal particles. Can not see how the trust bearing will not pick up debris.
> 
> Eric



A single row ball race will not perform well with thrust loads on the shaft, it's a good method to use small ball races combined with an end thrust bearing to give a compact, efficient solution to the problem, 

Nick


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## canadianhorsepower (May 13, 2018)

moditwell said:


> We get what we pay.



nasty comment

what do YOU have ???


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## Cogsy (May 13, 2018)

Nick Hulme said:


> A single row ball race will not perform well with thrust loads on the shaft


 
A good rule of thumb is that deep groove ball bearings can handle around 10% of their actual (not rated but actual) radial load as thrust load. So for light axial thrusts they can be used perfectly acceptably.


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## velocette (May 13, 2018)

Hi
"A single row ball race will not perform well with thrust loads on the shaft" 
This seems to be somewhat misleading for those just coming in to our hobby 
Even after ten years of  use a Lathe  and Mill Drill running 2x28x10mm 2RS bearings still with no problems still silky smooth. For the low rotational speeds involved they are more than adequate for the job. 
Alignment and accuracy of shaft parallel to the ways is essential for smooth running as well as decent bearings.
Ideal  solution for high thrust loads is two angular contact bearings with the correct preload and alignment.    May require deep pockets!!  
As always I will continue look at alternative ways to do a job and comment on it and it is not an attempt to prove who is right or wrong just encourage lateral thinking from our observations.
P.S.
Moditwell  looking forward to more of your posts Your setup works fine. 
Eric


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## Nick Hulme (May 14, 2018)

velocette said:


> Hi
> "A single row ball race will not perform well with thrust loads on the shaft"
> This seems to be somewhat misleading for those just coming in to our hobby



I tried both ways on my Myford Super 7 cross slide and can confirm that adding the thrust bearing makes it feel better and smoother. 
For me it's about using the available parts which are designed for a particular application where possible rather than settling for the less than ideal ;-)


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## goldstar31 (May 14, 2018)

GHT listed several 'improvements for both the ML7 and his Super 7 in his Model Engineers Workshop Manual

Regards


N


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