mesh of 10L thread dial to leadscrew

[jmm03]

Hello all, would anyone have a picture showing the gear to leadscrew mesh on a heavy 10 thread dial? Mine was broken and repaired during its previous life and I am not sure that the hold down bolt hole is in the right place. Thanks in advance. Jim

 

[Red James]

Proper meshing of the teeth is not important; only that the lead screw will drive the thread dial screw without jumping over a tooth. Backlash is not important.

 

[thomasutley]

If your machine has correct parts installed, and any repairs correctly performed, the mesh will be fairly obvious. Thread dials are driven by the leadscrew (a worm in gear terminology) via a worm wheel. The worm wheel will have teeth angled to correspond to the pitch of the leadscrew and it will have a concave face centered on the axis of the screw.

Hope that helps you determine what you have.

Best regards,

Tom

 

[jmm03]

thanks guys, I understand how it is supposed to work but the location of the gear relative to the screw is off and I was hoping for a view looking from the side to see if my suspicions are correct. (what is the casting number on the body of the dial? will that clue me as to it being for a 10L or another unit?) I elongated the hole to get it to work in the mean time as it was skipping. Thanks, Jim

 

[mdshunk]

Lathes, in general, seldom have the thread dial gear located on one of the quadrants of the lead screw (12,3,6 or 9 o'clock). Very often it makes contact somewhat below center, with the thread dial tilted toward the operator at a bit of an angle. As long as the radius cut in the face of the thread dial gear mates up decent with the diameter of the lead screw, you're golden. Having said that, I noticed on my one Asian lathe with a brand name that rhymes with Jet, the thread dial gear has no radius cut into the face. Just ordinary looking gear teeth; undoubtedly of some peculiar profile.

 

[jmm03]

Hi MD, yeah, the gear on mine has no radius either and it was only contacting the screw with about a 1/8" of the gear.