No announcement yet.

Slipping leadscrew

  • Filter
  • Time
  • Show
Clear All
new posts

  • Slipping leadscrew

    Just finishing up the restoration of my 1930 model "O" 9" and noticed that when I engage the half nuts the leadscrew slows or stops while the lathe runs. When I went through the QC box I didn't take it apart as it was in great shape and only needed cleaning. Is there a key in the gear that drives the leadscrew that could shear, I don't really remember when I reinstalled the leadscrew to the gear box? I can see in the gear box and the jam nuts and gears all seem fine, but I can turn the leadscrew when the lathe is shut off!! I have been running the lathe in all the different gears trying to get lubrication and just running it as it hasn't ran for many years. The leadscrew worked fine and there have been no mishaps or crashes with the machine while getting it up and running. So far only testing the machine operation, no actual machining yet.

  • #2
    There should be a shear pin on the leadscrew - one of the Southbend Guru's will be able to guide you - if you can't find it.


    • #3
      It sounds like you sheared a pin or key. My Clausing uses a 1/16" dia. aluminum pin to lock the lead screw to the output shaft of the quick change gear box.