# A question about sherline spindle



## lensman57 (Jan 10, 2012)

Hi To All,

This might be bit of a silly question but how does a Sherline Chuck is trued on the spindle if all it relies on is the spindle threads.

I have a Taig Micro lathe and although both Taig and Sherline have the same size spindle nose thread size the Taig relies on the shoulder at the back of the spindle to true the chuck, I believe that Sherline does not have this shoulder.

Just curious I guess.

A.G


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## Russel (Jan 11, 2012)

The Sherline lathe and mill spindle does have a shoulder on it. Both the spindle shoulder and the threads insure that chuck threaded on is straight. 

In this photo I'm using a .25" collet, but you can see the threads, and in the upper left corner of the photograph you can see just a little bit of the shoulder. (Sorry I don't have a better photograh of the spindle.)







This photograph is of a Sherline index block, also with a collet, but it is made just like the spindle so that a chuck can thread on to it. You can clearly see the shoulder on the index block.


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## bambuko (Jan 11, 2012)

It's not the shoulder, but register face that ensures concentricity of chuck and spindle.
For example:






Does Sherline have similar design? or does it rely on the thread and shoulder alone?

Chris


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## lensman57 (Jan 11, 2012)

Russel  said:
			
		

> The Sherline lathe and mill spindle does have a shoulder on it. Both the spindle shoulder and the threads insure that chuck threaded on is straight.
> 
> In this photo I'm using a .25" collet, but you can see the threads, and in the upper left corner of the photograph you can see just a little bit of the shoulder. (Sorry I don't have a better photograph of the spindle.)
> 
> ...



Hi Russel,

And thank you for your detailed reply, from the photos it indeed looks like Sherline does have either a shoulder or register to true the chuck, however I amongst many others have a Sherline 4 Jaws SC for my Taig micro lathe and I have read that at least some people have successfully machined a collar to mount the Sherline chuck on to the Taig, I am still not sure how they have achieved this as a collar alone only acts a spacer not a register and in my case at least despite my best efforts the chuck has about 0.003" of run out which is not acceptable. The shoulder on the Taig spindle also appears to my eyes to have a very slight taper but I would not go to court with this as it may just be result of my eyes astigmatism, LOL.
I would be greatfull if this issue could be cleared up as getting this chuck to run true has become an obssession of mine.

Many thanks for all the replies and best regards,

A.G


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## bambuko (Jan 11, 2012)

It is clear that Sherline:






uses just thread and shoulder face for location (source: *www.sherline.com*), 
whereas Taig (Peatol) uses more classical arrangement of face and diameter register (see details on the excellent site here: *http://www.lathe.com/spindles.html*)

Rest assured that dia B is not tapered 

You can make a washer (thicker than dim F) to clear register diameter, but I doubt that it would be totally satisfactory (although you might get away with it). You would need to make sure that the washer thickness is held to very high tolerance and hope that Taig(Peatol) thread is concentric. The problem is that because Peatol doesn't use thread for location (just to retain) it is unlikely to be as accurate as Sherline thread (which has to be accurate to ensure that chuck locates concentrically). 

You could get someone (with suitable machinery) to modify the back of Sherline chuck to suit Peatol, but you would probably be better off getting Peatol chuck ;D

Chris


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