[Newbie] Need Help Selecting New Chuck for South Bend 10

[Bob Korves]

One question you might ask yourself is what your expectations for the chuck are. 3 jaw chucks are
not known for precision, but if that's what you want, you'll need a set-tru chuck to get the runout to
a reasonable number. If you have the time you could try to find a Pratt or Bison in good shape on eBay
for that. If you want the chuck for first ops only, you could look into a Shars. Some folks around here are happy
with them. If you really want to do precise work, the four jaw is your friend.

Agreed! Pretty much anything you can do with a three jaw can also be done with an independent 4 jaw, just somewhat slower, but usually also more accurately.

 

[Nogoingback]

I suspect that the reason some people avoid the 4 jaw chuck is they don't practice dialing them
in enough to get good at it. With practice, it takes very little time.

 

[woodchucker]

Threaded mount. I believe it's 2.250 x 8

Also, I forgot to mention that the 3-jaw chuck is 5". The lathe also came with a cheap 6" 4-jaw that I was able to rebuild and that works fine now.

Also also, 5" or 6" on the replacement 3-jaw?

A skinner is not a cheap 4", if I remember that's what you had. I might be wrong, but I think it was a good chuck.

What 3" did you get with the lathe?

 

[karlsangree]

One question you might ask yourself is what your expectations for the chuck are.

As a machining newbie, my expectation at this early point in my journey is for the chuck to hold the material fairly straight, and then spin it around

I am waiting to get some input on 5" (which I currently have") or 6". It seems like 6" is better than 5" (that's what she said lol) but there must have been some reason the previous owner went with 5".

I did look at Shars and they have what looks to be a fairly decent 6" 3-jaw for about $250 and includes the 2 1/4 x 8 backing plate my lathe requires. Of course, it's out of stock.
Shars 6" with backing plate

 

[karlsangree]

What 3" did you get with the lathe?

3"? None. It came with two 5" 3-jaw chucks (one is totally trashed and missing parts), and one 6" 4-jaw. That's the one you so kindly help me rebuild.

 

[woodchucker]

I don't know where the " came from both on 4 and 3... brain fart.

replace jaw in that.

 

[mmcmdl]

Are you able to machine a backing plate or is this not an option ?

 

[Bob Korves]

As a machining newbie, my expectation at this early point in my journey is for the chuck to hold the material fairly straight, and then spin it around

It is time to learn how to dial in work on a 4 jaw chuck. It is not that difficult, and done properly gives more accurate results than using a 3 jaw chuck for many projects, without which leaves you susceptible to whatever inaccuracies exist in the lathe and the 3 jaw chuck. Properly using 4 jaw chucks is a major improvement to the results of your work and your options for doing work. Practice on scrap stuff and cutoffs that do not matter until you get it down. You will be happy that you did...

 

[karlsangree]

Are you able to machine a backing plate or is this not an option ?

I suppose if someone put a gun to my head and said "Make a backing plate or die" I could probably do it but given the option I probably would say no. For the time being this newbie has a little more money than machining skill. I'm trying... I'm out at the lathe just about every night after dinner hacking away and making chips. I just don't have a lot of confidence in my ability to hit the necessary levels of precision yet... but I'm getting there.

 

[Bob Korves]

As a machining newbie, my expectation at this early point in my journey is for the chuck to hold the material fairly straight, and then spin it around

A lathe is a much more versatile machine than making big ones into smaller ones on the same axis. Features need to be cut when away from the center as well, also dialing work to an accurate center. Do you have a dial indicator and an adjustable magnetic holder that will fit it? It is not difficult to learn dialing in work to center using the dial indicator, and the tooling can be inexpensive while opening many new options to what your lathe can do for you. Don't be afraid of it, many people have learned it before you, and it is much easier than you think it is...