# 13" Single South Bend Lathe Chuck Size Questions



## Janderso (Apr 25, 2018)

Hi,
I have the 1 7/8 8TPI spindle. That in itself is a challenge. I did find a 6" Cushman 4 Jaw chuck on Ebay that I have cleaned up and used. I also have a 6", 3 jaw fairly new Chinese chuck that is great.
My questions, what is the size of your largest chuck on your 13"
What do I do to center work on the other end of the head stock? I have the 1" hole.
What do you call the centering/locking device that is mounted on the opposite side from the chuck on the head stock?
I can make one if I had a drawing/diagram.
Thanks, I am a bit rusty, it's been a while since I ran a lathe = decades in fact.


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## Dave Paine (Apr 25, 2018)

The chuck size may depend on the max stock diameter you want to hold since you need to consider how far the jaws will stick out.

If you need to hold the stock centred at the outside end of the spindle, you need to make a spider.   Many threads on the forum showing different designs.    The spindle is hard so you need to either make one which fits inside the spindle, reducing the max stock diameter, or one which attaches on the outside - if you have room at the end of the spindle.

An example thread to illustrate.

Lathe spider thread


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## Technical Ted (Apr 25, 2018)

I've got an 8" Buck four jaw chuck on my 13" SB. Seems to be a good size for it. 

Ted


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## Bamban (Apr 25, 2018)

I am using a Bison 8 inch combination on my SBL 13, I think it is the perfect size for it. Spindle has D1-4 mount.


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## derf (Apr 25, 2018)

I have a 8" Buck 6 jaw on my 13. You can make a spider out of a section pipe and just add set screws. For pieces that don't go all the way through the spindle, I made a reverse center that grips the inside of the spindle. My spindle is 1-3/8 i.d.


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## Janderso (Apr 26, 2018)

Boy, They sure don't give me much to work with. I can see how to make a sleeve/spider to lock on the inside of the spindle, maybe I could turn an interference fit with small set screws, extend out an inch or so with set screws. I will lose some working ID though. Nothing to grab on to with the gear in the way.


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## derf (Apr 26, 2018)

Just thinking outside the box here....you could make a thick sleeve and screw it to the end of the gear by drilling and tapping the end of the gear in 4 places and use 10/32 screws.


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## Janderso (Apr 26, 2018)

You know Derf, I was heading that same direction. A co-worker asked me, why don't you fasten a collar to the gear cover housing? Hmm, if it was a flat surface maybe, but it is quite contoured. Surely someone has done this before. and don't call me shirley.
I wonder how hard that gear is?


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## derf (Apr 27, 2018)

That gear is softer than you think....slide a file across it.


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