What do I need to know about chucks before buying a four-jaw?

[BaronJ]

Waaay over my head! Whats a register?

It is the smooth area behind the threads.

 

[macardoso]

All the face plates I've seen that have been finished to suit a particular lathe spindle have already been machined to suit the register.
Are you saying that even though they are threaded, you still have to machine them to suit your machine register ?

I got one that the register was undersized 10 thou, took a week to figure out why it wouldn't thread on the spindle. I just bored it to the correct size. If they are correct from the factory, great! One less step.

This might have just been a one-off issue?

 

[BaronJ]

Hi Macardoso,

You had me bothered there I've just bought a new 125 mm chuck back plate, it came on Monday, I've not unpacked it yet.
If I have to start machining the register on a new stainless steel one, I'm not going to be happy ! They are dear enough as it is.

I'll report back on this one...

 

[MrWhoopee]

Here's a pretty good deal on a 160mm 4-jaw independent chuck.
https://www.ebay.com/itm/Four-Jaw-I...017736?hash=item23a873d0c8:g:-hQAAOSwpaZbfhxF
It doesn't state that it's a Sanou, but the K72-160 part number is a Sanou number.
I bought one of these for my SB Heavy 10L, which also has a 2-1/4 - 8 spindle nose. It's a nicely made chuck, though the jaws were very tight and required quite a bit of lapping (320 grit wet-or-dry on a flat plate) to make them move without both hands on the chuck wrench.
It doesn't come with the threaded backing plate, that will have to be purchased separately.

 

[BaronJ]

Hi Macardoso,

You had me bothered there I've just bought a new 125 mm chuck back plate, it came on Monday, I've not unpacked it yet.
If I have to start machining the register on a new steel one, I'm not going to be happy ! They are dear enough as it is.

I'll report back on this one...

Hi Macardoso, Guys,

Well I've unpacked my new one and it fits like a glove. No machining of registers here.


I,m happy with this. Those rust stains will vanish when I machine it.

 

[macardoso]

Hi Macardoso, Guys,

Well I've unpacked my new one and it fits like a glove. No machining of registers here.

View attachment 275415View attachment 275416
I,m happy with this. Those rust stains will vanish when I machine it.

Boy that is a pretty backplate!

 

[aliva]

I just posted a 4 jaw on the for sale board. It might work for you

 

[Mauser lover]

Had a look at it, and it sure looks nice, but it is out of my price range for now. Thanks though!

 

[Dabbler]

Mauser lover, you are on the right track. Until you get more used to accurate turning and threading, it is best to buy off-the-shelf. (besides it is faster to get up and going). Even if it is costly, you won't regret it. A 4 jaw chuck is basic equipment after all!

 

[Dabbler]

Have a look at this video and it's part 2. I think it will help.

This one is also pretty good