# Ineresting 4 Jaw Chuck



## Chuck K (Jun 27, 2017)

Lately I have been working on some chucks that came with a Hendey lathe I purchased.  It came with 2-3 jaw and 2-4 jaw chucks.  All of them were rusty.  Tonight was the first time I took a close look at the 8" 4 jaw.  It was just an extra chuck the fella had around and he gave it to me along with a backplate that he thought I might be able to use with it.  I set it on my bench to take it apart and quickly realized that it wasn't just an independent 4 jaw.  It is, but its also a scroll chuck.   I've never had a 4 jaw scroll chuck.  I always 
	

		
			
		

		
	




	

		
			
		

		
	
 pictured something similar to a 3 jaw with one extra jaw...and all of the same runout problems.


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## Dave Paine (Jun 27, 2017)

I saw a similar concept chuck in a YouTube video a few weeks ago.   A person on the comments found the patent.  The design has part of the jaw travel like an independent chuck and part like a scroll chuck.  I do not know how well this works in use, but it is an interesting design.


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## mikey (Jun 27, 2017)

Sherline makes a very nice little 4 jaw scroll chuck. I use it when I need to grab square stock and it works quite well.


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## 4GSR (Jun 27, 2017)

They call that a "combination" chuck.  Primary use was on turret lathes.  It allowed you to adjust each jaw independently for runout as well as for irregularly shaped parts.  Ken


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## Chuck K (Jun 27, 2017)

Dave Paine said:


> I saw a similar concept chuck in a YouTube video a few weeks ago.   A person on the comments found the patent.  The design has part of the jaw travel like an independent chuck and part like a scroll chuck.  I do not know how well this works in use, but it is an interesting design.


I'll get a better idea of how well it works once I get the scroll and the jaws out of it.  I have it soaking.  I think by tomorrow night I should be able to get it apart.


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## Chuck K (Jun 27, 2017)

4gsr said:


> They call that a "combination" chuck.  Primary use was on turret lathes.  It allowed you to adjust each jaw independently for runout as well as for irregularly shaped parts.  Ken


Thanks.  Learn something new everyday.


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## Groundhog (Jun 28, 2017)

That is an interesting chuck. Not sure how often I would use one, but I think I need one just to have one! That's something I could probably play with for hours without actually getting anything done!
Really though, it is probably very handy when used in some very specific circumstances. Like turning several identical cams or offsets.


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## benmychree (Jun 28, 2017)

I also have one, but have never mounted or used it ----   a solution in search of an application?  I imagine that it would be just the thing for some odd shaped casting done in quantity.


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## mksj (Jun 28, 2017)

A few of us have the 8" Bison version of this combination chuck, it is my primary chuck for anything over 1", otherwise I use my 5C collets. It has the benefits of a scroll, so quick stock insertion/removal and the precision of an adjustable 4J when you need to have minimal TIR. The repeatability of the scroll on mine is around 0.002". The Bison combination also has small jaw tips in contrast to most 4J independents, so you can hold stock as small as 0.200". I find it holds stock more securely than my 3J and less chance of twisting, and it holds stock in the axial (bed) direction more true than any of my other chucks. You can also use it for odd sized stock or irregular surface, this has been helpful in a number of projects. I have dual keys for the independent jaw adjusts, but really you can dial it in with in in less than a minute with a single key. I would take it over a standard 4J independent any day of the week, but then it comes at a price premium and it is probably 20+lBs heavier than my direct mount 4J independent that came with my lathe.

You may consider using some Evaporust on your chuck initially to clean it up, I wouldn't want to use anything corrosive like mild acids. Also keep track of the jaws relative to the slots, mine are all numbered. Look foward to hearing what you thing when you get it up and running.


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## Chuck K (Jun 28, 2017)

I finished taking it apart tonight.  This one was made by Union Mfg.  Interesting that you mentioned keeping the jaws in sequence.  This one had the jaws all mixed up.  I doubt that it has been used after it was last assembled.  I'm curious to see how it performs.  It's soaking in an electrlytic bath right now.


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## Chuck K (Jun 28, 2017)

mksj said:


> A few of us have the 8" Bison version of this combination chuck, it is my primary chuck for anything over 1", otherwise I use my 5C collets. It has the benefits of a scroll, so quick stock insertion/removal and the precision of an adjustable 4J when you need to have minimal TIR. The repeatability of the scroll on mine is around 0.002". The Bison combination also has small jaw tips in contrast to most 4J independents, so you can hold stock as small as 0.200". I find it holds stock more securely than my 3J and less chance of twisting, and it holds stock in the axial (bed) direction more true than any of my other chucks. You can also use it for odd sized stock or irregular surface, this has been helpful in a number of projects. I have dual keys for the independent jaw adjusts, but really you can dial it in with in in less than a minute with a single key. I would take it over a standard 4J independent any day of the week, but then it comes at a price premium and it is probably 20+lBs heavier than my direct mount 4J independent that came with my lathe.
> 
> You may consider using some Evaporust on your chuck initially to clean it up, I wouldn't want to use anything corrosive like mild acids. Also keep track of the jaws relative to the slots, mine are all numbered. Look foward to hearing what you thing when you get it up and running.
> View attachment 236524


I don't think there was ever a tme when one of my lathes was that clean.  Note to self:  don't post embarrasing pics of your grungy machines.


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## Randall Marx (Jun 29, 2017)

I believe (or try to believe) that most of us have machines that are _much_ less clean than Will's. Don't feel bad about not having spotless machines!


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## 4GSR (Jun 29, 2017)

Randall Marx said:


> I believe (or try to believe) that most of us have machines that are _much_ less clean than Will's. Don't feel bad about not having spotless machines!


No, but Will give us something to strive for....Clean machines!!!


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## davidpbest (Jun 29, 2017)

mksj said:


> A few of us have the 8" Bison version of this combination chuck, it is my primary chuck for anything over 1", otherwise I use my 5C collets. It has the benefits of a scroll, so quick stock insertion/removal and the precision of an adjustable 4J when you need to have minimal TIR. The repeatability of the scroll on mine is around 0.002". The Bison combination also has small jaw tips in contrast to most 4J independents, so you can hold stock as small as 0.200". I find it holds stock more securely than my 3J and less chance of twisting, and it holds stock in the axial (bed) direction more true than any of my other chucks. You can also use it for odd sized stock or irregular surface, this has been helpful in a number of projects. I have dual keys for the independent jaw adjusts, but really you can dial it in with in in less than a minute with a single key. I would take it over a standard 4J independent any day of the week, but then it comes at a price premium and it is probably 20+lBs heavier than my direct mount 4J independent that came with my lathe.
> 
> You may consider using some Evaporust on your chuck initially to clean it up, I wouldn't want to use anything corrosive like mild acids. Also keep track of the jaws relative to the slots, mine are all numbered. Look foward to hearing what you thing when you get it up and running.
> View attachment 236524



Oh fiddlesticks.   Now you tell me about this chuck!   I knew there were 4-jaw scroll chucks, but didn't realize the jaws were also independently adjustable for TIR.   OK, I give up now - where, and how much?


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## mksj (Jun 30, 2017)

Matt sells Bison chucks, and his pricing was the lowest I have seen, but they are also sold through Ajax, Grizzly and a few others. Bison Scroll Chuck - 8" Plain Mount, 4-Jaw 7-848-0800. Cost is about the same as a 6J Bison.
https://www.toolmex.com/itemdetail/7-848-0800
http://www.ajaxtoolsupply.com/biscc...biscch8plmo4&gclid=CNjp9-rs5NQCFURlfgodhq4Klg
I use a Gator D1-4 back plate, which is less expensive than the Bison back plate but you do need to do the final registration cut on the step to match the chuck. But I would check with Matt first, as his pricing with the Bison back plate may be close to the Gator.
http://www.gts-tools.com/catalog/products.php?id=FLD-200D4&cid=d-gab-a-pbsc

The 4J combo is my primary use jawed chuck, the PBA 3J scroll I use when I have a lot of repeat pieces to make or multiple in/out operations on a piece. I think it is all a matter of preference, but you do need to tweak the jaws to get the TIR down to zip. The nice thing is you can make sure that all the jaws have even pressure on the stock.


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## Nogoingback (Jun 30, 2017)

David, I don't know if these guys have the chuck you're looking for, but their prices are great.  I purchased a Bison from them and had no problems.  You might check them out.
http://www.rlstephenstool.com/lathe_chucks.htm


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## gonzo (Jul 1, 2017)

Chuck K said:


> I finished taking it apart tonight.  This one was made by Union Mfg.  Interesting that you mentioned keeping the jaws in sequence.  This one had the jaws all mixed up.  I doubt that it has been used after it was last assembled.  I'm curious to see how it performs.  It's soaking in an electrlytic bath right now.


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## gonzo (Jul 1, 2017)

I have one also. It came with my lathe.
Given the choice, why have a standard 4 jaw when you can have one like this?


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## gonzo (Jul 1, 2017)

Oops, this isn't a 4 jaw, but you get what I mean.


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## Chuck K (Jul 1, 2017)

gonzo said:


> Oops, this isn't a 4 jaw, but you get what I mean.


Yep...every 3 jaw should have independent adjustment.  Finished mine today.


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## mksj (Jul 1, 2017)

Absolutely gorgeous once you cleaned it up, looks like it saw very little use through the years. Great score . I think the combination chuck offers a lot of advantage of the standard 4J independent (but at almost twice the cost of a direct mount). Haven't seen them in a 3J version, so thank you for posting. As an all around chuck they are a pleasure to use, you should be able to get a repeatability of the scroll to around 0.002-0.003 once the jaws are dialed in evenly. The individuals jaws have a fairly wide adjustability range used independently, but they need more than a few teeth to hold a piece securely.


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## Chuck K (Jul 1, 2017)

mksj said:


> Absolutely gorgeous once you cleaned it up, looks like it saw very little use through the years. Great score . I think the combination chuck offers a lot of advantage of the standard 4J independent (but at almost twice the cost of a direct mount). Haven't seen them in a 3J version, so thank you for posting. As an all around chuck they are a pleasure to use, you should be able to get a repeatability of the scroll to around 0.002-0.003 once the jaws are dialed in evenly. The individuals jaws have a fairly wide adjustability range used independently, but they need more than a few teeth to hold a piece securely.


I'm real happy with the way it cleaned up.  I don't have a backplate for it and it appears that the previous owner didn't either.  It has divots all over the sides of the bottom section (you can see them if you zoom in) where it was held in the jaws of a larger chuck.  As heavy as it is,  I'm not going to do that on my 15" Polamco.  The weight of two chucks plus a work piece hanging on the end of the spindle seems a bit much.  I don't do a lot of multiple offset work so I don't feel inclined to buy a camlock backplate for it.  It's not hard to dial a common 4 jaw in to 0.001 if you use one a lot.  I think for now I'll just stick with my 4 jaw, 3 jaw scroll with soft jaws, and collets.  The combination chuck will make a good conversation piece.


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