4 Jaw Chuck ID

U

upcondor

Aluminum

Joined

Jul 22, 2011

Location

Texas

• Nov 23, 2018

• #1

I was given an 8” 4 Jaw Chuck that is 1.5 x 8tpi. It has 6645-1 stamped on the back of it. I have a SB Model 9a with of course the same 1.5 x 8” spindle tpi.

The chuck will thread on to the spindle but tightens short of being against the spinde shoulder.

My question to the forum is does anybody know based on the chuck model number if it SHOULD fit the South Bend or is made to correctly mount up to some other brand lathe only ?

Thanks for any help,

Tom

 

R

Rob F.

Diamond

Joined

Aug 5, 2012

Location

California, Central Coast

• Nov 23, 2018

• #2

Check the locating area is clean and not rusty or dinged up. Both chuck and spindle.

 

U

upcondor

Aluminum

Joined

Jul 22, 2011

Location

Texas

• Nov 23, 2018

• #3

Ok, spindle is immaculate, I will check the thread on the chuck again.

Thanks

 

I

iwananew10K

Diamond

Joined

Sep 12, 2010

Location

moscow,ohio

• Nov 23, 2018

• #4

usually that is the result of a nominal diameter (1.5")counterbore in the chuck backplate while the SB spindle is about .010" over nominal at the register diameter.

measure those and see if that's the problem, if so bore out the chuck backplate to fit.

 

U

upcondor

Aluminum

Joined

Jul 22, 2011

Location

Texas

• Nov 23, 2018

• #5

More good info, appreciate the help...

Thanks

Tom

 

R

Rob F.

Diamond

Joined

Aug 5, 2012

Location

California, Central Coast

• Nov 23, 2018

• #6

upcondor said:

Ok, spindle is immaculate, I will check the thread on the chuck again.

Thanks

Click to expand...

Not the thread, the precision flat area before the thread. It should pretty much be an exact fit to spindle shaft, just a couple tenths clearance This keeps chuck centered, the threads just hold it on.

 

U

upcondor

Aluminum

Joined

Jul 22, 2011

Location

Texas

• Nov 23, 2018

• #7

Ok will do !

Tom

 

B

Blob

Hot Rolled

Joined

Apr 7, 2007

Location

Scotts Valley, CA

• Nov 23, 2018

• #8

I had a face plate that did the same thing, and it turned out to be a slightly buggered up thread, so I'd also check the thread.

 

U

upcondor

Aluminum

Joined

Jul 22, 2011

Location

Texas

• Nov 23, 2018

• #9

Ok, after taking some good measurements looks like it is the area before the thread. Going to have to be bored out 2 thou.

Thanks for helping out,

Tom