Ineresting 4 Jaw Chuck

Chuck K

Active User
H-M Supporter Gold Member
Joined
Mar 1, 2013
Messages
1,132
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 20170627_192809.jpg 20170627_201315.jpg pictured something similar to a 3 jaw with one extra jaw...and all of the same runout problems.
 
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.
 
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.
 
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
 
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.
 
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.
 
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.
 
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.
 
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.
20150415_080254.jpg
 
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.
 
Back
Top