Scrolling 4-jaw chucks

[radius]

Is there any disadvantage to a scrolling 4-jaw chuck? My thinking is it would be quite versatile, it could hold both round and square stock and to a certain degree spread the pressure on thin wall stock. Look forward to insights/opinions. ( first post, enjoying the site ) Radius

 

[xalky]

Is there any disadvantage to a scrolling 4-jaw chuck? My thinking is it would be quite versatile, it could hold both round and square stock and to a certain degree spread the pressure on thin wall stock. Look forward to insights/opinions. ( first post, enjoying the site ) Radius

Think about a 3 legged stool verses a 4 legged stool. With a 3 legged stool all the legs contact the floor, not necessarily so with a 4 legged one. This is why 4 jaw chucks are more useful when the jaws are independently adjustable. I think you'd get much more versatility out of a 4 jaw independent chuck. If you want speed and ease of use for round stuff, get a 3 scroll chuck. I feel you rellay should have a 3 jaw scroll chuck and a 4 jaw independent chuck. If funds are limited, just get a 4 jaw independent chuck for now.

 

[darkzero]

A 4 jaw scroll chuck would be useful if you work with a lot of square stock for quick & easy chucking without the need for high precision. With a 4 jaw scroll you wouldn't be able to hold hex stock or bolts which I find useful. A 4 jaw scroll also won't have as much clamping force as a 3 jaw or 4 jaw independent. As you mentioned it would be a bit better for thin wall workpieces but a 6 jaw is best for that.

I also would rather have a 3 jaw & a 4 jaw independent. A 4 jaw independent would also allow you to hold rectangle & odd workpieces as well as dial in work to high precision. I personally use a 6 jaw & 4 jaw independent.

 

[John Hasler]

Think about a 3 legged stool verses a 4 legged stool. With a 3 legged stool all the legs contact the floor, not necessarily so with a 4 legged one. This is why 4 jaw chucks are more useful when the jaws are independently adjustable. I think you'd get much more versatility out of a 4 jaw independent chuck. If you want speed and ease of use for round stuff, get a 3 scroll chuck. I feel you rellay should have a 3 jaw scroll chuck and a 4 jaw independent chuck. If funds are limited, just get a 4 jaw independent chuck for now.

There might be some use for a 4-jaw where only opposing jaws are synchronized. Rather specialized, though.

Or you could really go wild and put a high-resolution DRO on each jaw of an independent 4-jaw.

 

[bjmh46]

I'll be the dissenter here. I love my 4-jaw scroll chuck (Bison, Poland) bought about ten years ago. I already had 3-jaw scroll, 4-jaw independent, and Sjogren 5C collet chuck. It stays on the lathe most of the time. Yes you can hold hex in it, just don't gorilla the wrench, 'cause it side loads the jaws. Mine is still within a thou centering and repeatability (on od ground stock). My next most used chuck is the 4-jaw independent, then comes the 3-jaw which I've pretty well dedicated to soft jaws. Haven't had the collet chuck on the machine in so long, I can't remember the last time. I used to use 5C square collets with it, and that was handy, but don't have the need anymore with the 4-jaw scroll. I've also got soft top jaws for the 4-jaw scroll, and a neat feature is that you can remove the top jaws, and install only two top soft jaws, and get the function of a 2-jaw scroll chuck. All in all, it's a very versatile chuck, and I wouldn't be without it!

That said, I agree that order of purchase should be 4-jaw independent, 3-jaw scroll (and soft jaws!), then the 4-jaw scroll.

Regards
Bob

 

[george wilson]

I love my 8" Bison 4 jaw universal too. It runs to .001 as well. It stays on my large lathe a lot. But,since I tend to do small work,I do use my HLVH most of the time,and mostly with collets. So,I'm not the best judge of what you should have. It depends upon what you're doing.

Obviously a 4 jaw independent chuck is the most versatile,and the most accurate if dialed in very accurately. If you could only have 1 chuck,it would be the one to have.

 

[tommied]

I too have a scroll 4 jaw that I leave on the lathe most of the time. Just seems to fit what I do the most often. If I have to hog off metal it will slip so I change it. Coarse I have 3 jaw, 6 jaw, independent 4 jaw so if you can just keep collecting as you are able cause there is no such thing as too many tools.


tommie

 

[d.brown]

I love my 8" Bison 4 jaw universal too. It runs to .001 as well. QUOTE]

Make that 3 for love it. A little on the pricey side but a real convenience. Mine has both sets of jaws but the newer one have top revering jaws.

David

 

[george wilson]

Luckily,I bought mine before the big price jumps a few years ago. I have bought about 5 or 6 of these 8" 4 jaw scroll chucks(Bison) over the years as toolmaker. As we got better lathes,the chuck on them went with them when they were sold. Back then,the chucks weren't nearly so expensive,though I can't recall how much they were.

Bison also makes a combination 4 jaw chuck. This chuck is a newer item,and the jaws can be adjusted with the scroll,or adjusted individually. I wonder how consistently accurate they are when used as a scroll chuck. Seems to me like the individual adjustment screws might drift a bit and the work would not be gripped real accurately,requiring adjustment every time they are tightened. Too expensive to take a chance on,too.

The combination chucks are not a new idea. Back in the early 70's, I knew a guy who had a real old 3 jaw(YES,3 JAW) combination on his lathe. It looked ancient. I doubt it was real accurate until adjusted,but he didn't demonstrate it in use.

 

[radius]

Thanks to every one for your responses. For now, will stick with my 3 jaw and put in some more hours/days to see where the work takes me. Thanks, Radius.