# 4 jaw lathe chuck



## niner (Nov 17, 2009)

I'm going to get a 4 jaw independent chuck, but not sure which one to get. Bison has a regular 4 jaw chuck (7-850-0500), and 4 jaw combination chuck (7-848-0500) which open/close all 4 jaw at the same time.

http://brassandtool.com/FL-Chucks-4-Jaw.html

What would you do?


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## Sheikh Jabril (Nov 17, 2009)

Can't go wrong with Bison, I've used them at home and commercially. 

They will outlast you, given a little care...

I just bought a 6 jaw....


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## brickbat (Nov 18, 2009)

I'd go for the 'regular' 4 jaw. I only use a 4-jaw when I have something heavy, and want to exert as much clamping force as possible. Having a scroll back in the picture seems like an issue. If you don't already have one, spend the $$ you save on a nice NOGA magnetic base for your dial indicator, which you'll use a lot every time you break out the 4-jaw...


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## precisionworks (Nov 18, 2009)

> NOGA magnetic base


+1

Just under a Franklin but worth every penny.


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## sawlight (Nov 18, 2009)

The joy, and pain, of a 4 jaw chuck is the ability to make not so round things round, and to offest turn on occasion. They can be misearble to get true, but the results are astounding.
Say you have a "square" that isn't exactly "square", the independent jaws will work, the jaws that move as one, wont.


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## gadget_lover (Nov 19, 2009)

> They can be misearble to get true




There are some very simple ways to get round stock trued very quickly in a 4 jaw independent. I can do it within 30 seconds, much less if I only need it close.

I've not seen a 'combination' scroll + independent before. An interesting concept for when you need to hold irregular work and re-chuck it with reasonable accuracy. Adjusting it may be more of a hassle, but once adjusted it should stay accurate for that particulate size.

Let us know how it works for you. 

Daniel


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## niner (Nov 19, 2009)

Bison won't have the combination chuck in stock until 1Q next year. That 's what my vendor told me. I would have gotten it if it is availbale.


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## niner (Dec 21, 2009)

I got the Bison 4-jaw combination chuck from a local dealer a few weeks agao. Finally, I got some free time to mount it on my lathe.

Very nice. As other people have said, centering the stock is not too bad. It took me about 5 minutes to center a 3/4" precision rod in the chuck. Runout is held to 0.0002. With this particular combination chuck, the repeatability is very good as well.


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## saltytri (Dec 21, 2009)

Wabeco, eh?


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## niner (Dec 21, 2009)

saltytri said:


> Wabeco, eh?


 
Yes, Wabeco D2400E.


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## saltytri (Dec 21, 2009)

Very nice. D600E here. How is yours working out?


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## precisionworks (Dec 21, 2009)

> Runout is held to 0.0002"



Is there any reason that you can't get it down under one tenth 

4-jaw chucks are a nice addition, as are a few face plates. Between those two, there's almost nothing that cannot be mounted & turned.


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## niner (Dec 21, 2009)

saltytri said:


> Very nice. D600E here. How is yours working out?


 
I haven't done much so far. The lathe is very rigid, but too light. I need to bolt it down on the bench. I also need to finish the DRO install. I had DRO on my old lathe, so I'm used to and depended on DRO.


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## niner (Dec 21, 2009)

precisionworks said:


> Is there any reason that you can't get it down under one tenth
> 
> 4-jaw chucks are a nice addition, as are a few face plates. Between those two, there's almost nothing that cannot be mounted & turned.


 
Lack of patient I guess To get that last one tenth, I probably need to spend another 5-10 minutes.

Face plate turing is something I never tried.


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## precisionworks (Dec 21, 2009)

I have one job that runs a few hours every month (some would say a bread & butter job). The part has a circular ID & a consistent, non-circular OD. Plus it is pretty thin, about 1/2" total thickness. It could be 4-jawed, but each new part would have to be indicated in.

Instead, I took a face plate and mounted a steel plate on it. The steel plate has the three bolt holes tapped to hold the part, and there is enough slop in the fit of the bolts to their holes that the part can be indicated in ... not too precisely, usually +/- .005". That really doesn't matter, as nothing is coming out of the bottom of an existing groove, just the side walls are being shaved off to give greater width. When done, each side wall measures about 1 mm thickness, so this is an unforgiving job.

It took about three hours to build the faceplate fixture, plus a few hundred bucks worth of specialized tooling, but that small investment had a payback of less than one month. And that was over five years ago :thumbsup:

Faceplates are awesome for specialty work that runs on a repeat basis, but the 4-jaw is king for anything not round, or for round parts that need an eccentric (like a crank shaft), or for really close accuracy. They set up pretty quickly with practice.


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## niner (Dec 21, 2009)

precisionworks said:


> I have one job that runs a few hours every month (some would say a bread & butter job). The part has a circular ID & a consistent, non-circular OD. Plus it is pretty thin, about 1/2" total thickness. It could be 4-jawed, but each new part would have to be indicated in.
> 
> Instead, I took a face plate and mounted a steel plate on it. The steel plate has the three bolt holes tapped to hold the part, and there is enough slop in the fit of the bolts to their holes that the part can be indicated in ... not too precisely, usually +/- .005". That really doesn't matter, as nothing is coming out of the bottom of an existing groove, just the side walls are being shaved off to give greater width. When done, each side wall measures about 1 mm thickness, so this is an unforgiving job.
> 
> ...


 
Thanks Barry. I learnt a lot by reading your posts. However, my wallet doesn't appreciate your contribution:mecry:


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## precisionworks (Dec 21, 2009)

> my wallet doesn't appreciate your contribution


Just remember that you are helping us out of the recession 

If you don't already have a face plate for your lathe, they are inexpensive on eBay. There may come a time when the 4-jaw is giving you fits and you remember the lowly face plate hanging on the pegboard. They are pretty useful for something so simple.


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