Rhom chuck ID

[Aukai]

Thank you, I'll have to see if I can improve the runout a bit.

 

[mksj]

Adjustable scroll chucks (Set-Tru, Setrite, etc.) have a separate back plate with a longer nose, there would be 3 or 4 small set screws around the diameter that cinch up against the nose to give about 0.005"adjustment in any direction. The securing bolts are around the outer peripheral front of the chuck. A direct mount D1-4, the only adjustment would be to regrind the jaws, they also need to be kept under tension with a ring when grinding.

PBA Setrite 160mm (6-1/4")

 

[woodchucker]

I keep wondering why a normal chuck with a deep recess in the back can't be converted over to a set-tru. Just put 4 set screws in the chuck, and enlarge the holes by a slight amount. My backing plate has plenty of meat to deepen it's shoulder or journal into the back of the chuck further.

 

[Aukai]

Thank you Mark, I'm curious about the stamping in the first picture. I'll try the different mounting positions, then changing the mounting pin orientation to see if the runout can be improved. Grinding probably wont happen here.

 

[Just for fun]

So, what does this mark indicate?



I suggest taking it apart and see what makes it tick if you will. It's an idea anyway.... I didn't say it was a good idea.

Tim

 

[Weldingrod1]

Left hand screw?

Sent from my SM-G892A using Tapatalk

 

[woodchucker]

I think maybe it's a cam screw, even though it's not a set tru chuck, it looks like that might be an adjustment. I am going by the look of the head of the socket appears to be to one side of the hole. It might only allow for 1 or 2 thou.

Take it apart and see, it probably needs a cleaning anyway.

 

[mattthemuppet2]

probably those 3 bolts hold the back of the chuck (not backplate) on, the bit that holds the scroll in. Never heard of an adjustable scroll chuck, only one where you move the whole chuck relative to the backplate/ spindle, but you never know.

 

[talvare]

I'm not sure what the X marking is about, could it be an indication that the chuck is threaded, and
must be used for lathe-in-forward machining?

Exactly. That is a warning label addressing the issue of running a screw-on chuck in reverse.

Ted

 

[tjb]

Rohm's US headquarters is in Suwanee, GA - about fifty miles from where I live. I just acquired an 8" Rohm New-Open Box on eBay that needs a backing plate. Their phone # is 770-963-8440. Very helpful staff.

Regards,
Terry