Non-scrolling 3-jaw 8" reversible lathe chuck operation

This lathe chuck has a back plate that fits a 13" South Bend Lathe 2-1/4"x8" /TPI but I am guessing that it would fit any brand

name with the same spindle threaded nose. I was looking on eBay for a 3 jaw scrolling chuck near 8" in diameter. I found this

one for $149.00 and a shipping cost of around $21.00. I did not read the small print saying it was non-scrolling. It is in great

condition but I have searched YouTube for an explanation and there is none there to be found. I have a 12.5" 4 jaw chuck and

a 10" 4 jaw chuck and over 53 5C collets up to 1-1/16". My guess is that no one will be interested in this 3 jaw so it's

important to learn the method of adjusting it to zero with a piece of round or odd shaped piece in it and not take all day to do so. I have labeled myself as so feel free to join in.

If it's too much to deal with for a beginner then I will take a big loss apparently. You would think I'd be used to it by now.

Maybe it can be modified for another use, I really don't know. Any suggestions are welcome.

What's the lowest beginner point for members and then the next 3 under that?

An independent 3 jaw can be very handy.

michiganbuck said:

An independent 3 jaw can be very handy.

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Thank you Sir, do you have any resources that would explain it's uses? I'm thinking that instead of 4 jaws to spin to I would

have 3 has that's the limit of the non-scrolling features. I'm also guessing that by trial and error I would learn which way to

move and which jaw to pay attention to. I have a brand name on it that I will get and post, it is USA if I remember correctly. I

don't think I need a scrolling 3 jaw chuck at the moment. It only takes a minute to dial in the 4 jaw and with the collets I can

grab any thing from a 1/16" to 1-1/16". Don't you think that a 12.5" 4 jaw chuck is a little large to use by a hobbyist? Both my

4 jaw chucks are smooth as silk but it's a lot of weight to be spinning at the end of the spindle. I can see by talking about it

that it would depend on what I'm going to turn. I have some pipe flanges to clean up and it would be perfect for that, gives

me practice and several different shaped tool bits to try out. I'm eager to learn and willing to learn which goes to show you

that old dogs can learn new tricks. lol

Greenlee52 said:

Thank you Sir, do you have any resources that would explain it's uses? I'm thinking that instead of 4 jaws to spin to I would

have 3 has that's the limit of the non-scrolling features. I'm also guessing that by trial and error I would learn which way to

move and which jaw to pay attention to. I have a brand name on it that I will get and post, it is USA if I remember correctly. I

don't think I need a scrolling 3 jaw chuck at the moment. It only takes a minute to dial in the 4 jaw and with the collets I can

grab any thing from a 1/16" to 1-1/16". Don't you think that a 12.5" 4 jaw chuck is a little large to use by a hobbyist? Both my

4 jaw chucks are smooth as silk but it's a lot of weight to be spinning at the end of the spindle. I can see by talking about it

that it would depend on what I'm going to turn. I have some pipe flanges to clean up and it would be perfect for that, gives

me practice and several different shaped tool bits to try out. I'm eager to learn and willing to learn which goes to show you

that old dogs can learn new tricks. lol

Click to expand...

preforming an off center operation (drilling, boring, sholder, groove etc) on hex stock is one.

It can be loosened with one jaw, and go back to near zero with tightening one jaw / can hold hex stock correctly with one jaw tightening for near/about size or be trued in with an indicator..often an old 3 jaw is off .003 to .020 and there is no recourse to make it true except for grinding the jaws or adding a dead true backing plate, whereas the independent can be independently adjusted true.

QT:[adjusting it to zero with a piece of round or odd-shaped piece in it and not take all day to do so.]

Back in the day that I did lathe work, I could adjust in a 4 jaw independent to .002/.003 in less than 4 minutes with just looking at my tool bit space from the part, with an indicator, and get .001 amd less in perhaps 5 minutes. Just about any lathe hand can do the same.

But yes for some a scroll chuck is the ticket..for me, it would need to do .002 or less.
I did have new 3 jaw scrolls for grinding that did .001 and better, top chucks, and near new.

michiganbuck said:

It can be loosened with one jaw, and go back to near zero with tightening one jaw / can hold hex stock correctly with one jaw tightening for near/about size or be trued in with an indicator..often an old 3 jaw is off .003 to .020 and there is no recourse to make it true except for grinding the jaws or adding a dead true backing plate, whereas the independent can be independently adjusted true.

QT:[adjusting it to zero with a piece of round or odd-shaped piece in it and not take all day to do so.]

Back in the day that I did lathe work, I could adjust in a 4 jaw independent to .002/.003 in less than 4 minutes with just looking at my tool bit space from the part, with an indicator, and get .001 amd less in perhaps 5 minutes. Just about any lathe hand can do the same.

But yes for some a scroll chuck is the ticket..for me, it would need to do .002 or less.
I did have new 3 jaw scrolls for grinding that did .001 and better, top chucks, and near new.

Click to expand...

Man, that is some great examples on some of the operations a non-scrolling chuck can do. I can back off my meds now and settle down enjoying

my new chuck. No kidding, I figured I'd screwed up again. Thanks so much. I'm not as fast as you with a 4 jaw but I can get it within .002 once I get

back on it and run it through the paces. It's great to still be learning.

Still, it is a shame that chucks are often listed with not stating independent or self-centering, but I guess that is part of the learning process to think about that or ask.
4 jaws are made in self-centering but not as popular as independent 4s
Having a square part production job a self-centering 4 jaw would/might be the berries.

Chucks have two functions of placing the part to the spindle center and wobble.
Wobble is like two ends of a pert going in a different circle.
In a crap 4jaw independent one might indicator a part to zero and two inches away have .003 run out(wobble).

When minimum concentricity and minimal wobble is needed then placing the part between centers is the solution.

*Learning how to be quick to go between the centers is a needed talent for a lathe guy.
Putting a slug ( a soft piece of round stock)in a chuck and turning a 60* is a quick way for the head end, best to know where the exact 60* is on your compound dial but you don't mark the machine you just make a note of it (perhaps one line width to the right). Yes, you just dog off a chuck jaw and put the out end on the tail center. This to beat the time of pulling the chuck and putting in a center.

In my lathe days with not perfect lathes and chucks, I had to go between centers often.