# Purchasing 4 jaw chuck



## OrangeAlpine (Feb 14, 2013)

My 8" 4 jaw suddenly came down with a severe case of sprung jaws.  Tried to mill them back to square, but the material is too hard.  So I've started looking at new chucks.

In short, how does a fellow identify a decent quality chuck?  My jaws seem to be made of good material, just too narrow (.790").  That parameter is not listed on the chucks I've looked at.  Should I shop by price?  Seller? Weight?  Thickness of the chuck body?  Length of jaw extending beyond the chuck body?  Brand? If brand, which ones to avoid or pursue.

Bill


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## GaryK (Feb 14, 2013)

OrangeAlpine said:


> My 8" 4 jaw suddenly came down with a severe case of sprung jaws.  Tried to mill them back to square, but the material is too hard.  So I've started looking at new chucks.
> 
> In short, how does a fellow identify a decent quality chuck?  My jaws seem to be made of good material, just too narrow (.790").  That parameter is not listed on the chucks I've looked at.  Should I shop by price?  Seller? Weight?  Thickness of the chuck body?  Length of jaw extending beyond the chuck body?  Brand? If brand, which ones to avoid or pursue.
> 
> Bill



Price is always a concern, but so it getting what you need.

I would try to get a direct mounting chuck just to keep down the wright.

What kind of spindle does your lathe have?

Gary


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## OrangeAlpine (Feb 14, 2013)

Spindle is 2 1/4" - 8.

Bill


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## JohnAspinall (Feb 14, 2013)

Can I jump in here with a related question?  I bought an 8" 4-jaw from CDCO, plus backplate for a 2 1/4 - 8 spindle, just like the original poster has.
But in an effort to save weight and cost, it's just a 6" backplate.  Now the registration surface has plenty of area - the recess is around 4" diameter.
And the mounting holes are inside that 4" dia, so I have a hard time believing that the contact out at the 8" dia is really important.  But am I missing something?
Am I going to regret this later?


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## GaryK (Feb 14, 2013)

OrangeAlpine said:


> Spindle is 2 1/4" - 8.
> 
> Bill



Well I'm not aware in any direct mount chucks for your spindle. Gator/Fuedra chuck are very good. You will have to buy a back plate for you spindle but that's true
no matter what chuck you buy. TOOLS4CHEAP has some of the best prices. I just bought a real nice 6 jaw chuck from them.

Gary


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## Ray C (Feb 14, 2013)

If it fits and the chuck face is perfectly perpendicular to the ways, it'll probably work but, be really careful that you never catch a finger in the 1" gap.  Some folks have a tendency to put their hand on the chuck while it's spinning down.  -Not a good idea.  Also, weight difference between a 6 and 8" plate is probably not that much (a few pounds maybe) which is simply not an issue for any normal lathe.

Ray



JohnAspinall said:


> Can I jump in here with a related question?  I bought an 8" 4-jaw from CDCO, plus backplate for a 2 1/4 - 8 spindle, just like the original poster has.
> But in an effort to save weight and cost, it's just a 6" backplate.  Now the registration surface has plenty of area - the recess is around 4" diameter.
> And the mounting holes are inside that 4" dia, so I have a hard time believing that the contact out at the 8" dia is really important.  But am I missing something?
> Am I going to regret this later?


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## JohnAspinall (Feb 14, 2013)

Ray C said:


> If it fits and the chuck face is perfectly perpendicular to the ways, it'll probably work but, be really careful that you never catch a finger in the 1" gap.  Some folks have a tendency to put their hand on the chuck while it's spinning down.  -Not a good idea.  Also, weight difference between a 6 and 8" plate is probably not that much (a few pounds maybe) which is simply not an issue for any normal lathe.
> 
> Ray



Thanks, Ray.   The weight issue is about lifting it by hand while I mount/remove it.  It's up near the limits of what I can handle easily.


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## Ray C (Feb 14, 2013)

I hear you on that.  Busted one wrist twice and sprained the other pretty bad.  Hurts pretty good some days.  No fun getting that 8" on there.



JohnAspinall said:


> Thanks, Ray.   The weight issue is about lifting it by hand while I mount/remove it.  It's up near the limits of what I can handle easily.


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## ScrapMetal (Feb 15, 2013)

JohnAspinall said:


> Thanks, Ray.   The weight issue is about lifting it by hand while I mount/remove it.  It's up near the limits of what I can handle easily.



It'd be real easy to make a "C" shaped chuck holder that clamps in the jaws and use a small shop lift, rig up a small crane arm, etc. to do the actual lifting.  I've seen setups like that posted on here but couldn't find one for the post.

-Ron


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## GK1918 (Feb 15, 2013)

I have had no luck with milling jaws.  I grind them by eye, and with round stock chucked up, I put the
jaw I just ground, back in,get a measurement with a feeler gage, tweek it some more till it is flat,
to the stock and do the other three.  Even if one is ground a little more, 4Jaws (independant) dont
care.  3 Jaw, whole different ballgame.  My chuck Im talking about is 70Yrs old and was a school
lathe so???  Now its back to normal.  If this helps, the old man insisted on rapping a brown paper
bag strip around the work on all machines, and its gotta be, "brown" bag, something to do with
a clay content.  Common problem is drilling, sometimes pushing the stock right into the headstock
no matter how tight you tighten it, the brown bag stops that, the slipping is no good for jaws.
Right or wrong grinding jaws works for me.


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## OrangeAlpine (Feb 16, 2013)

GK1918 said:


> I have had no luck with milling jaws.  I grind them by eye, and with round stock chucked up, I put the
> jaw I just ground, back in,get a measurement with a feeler gage, tweek it some more till it is flat,
> to the stock and do the other three.  Even if one is ground a little more, 4Jaws (independant) dont
> care.  3 Jaw, whole different ballgame.  My chuck Im talking about is 70Yrs old and was a school
> ...



Thanks, I think I'll give it a try.  

Bill


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