View Full Version : Backlash in Cross Slide Lead Screw on Prazi D2400E Lathe

02-10-2005, 03:19 PM
Hi All,
I am seeing backlash in lead screw for the cross slide. Can anyone tell me if this is adjustable and how? The manual is poor on maintenance. Any inputs is appereciated.

02-10-2005, 04:04 PM
Some smaller lathes use a cross slide nut which is slit (perpendicular to its axis) and a setscrew which expands that slit, moving several turns of the thread away from the others, reducing the play. If such an arrangement exists, you may see several screw heads on the top of your cross slide (maybe one or two to secure, one to adjust or something like that).

Others with no adjustment at the nut may have adjustment behind the micrometer dial although this would only remove play from the handwheel bushing or bearing. On some small Emco machines, this is a spanner nut visible after the handwheel and dials are removed.

There are probably other methods but these are pretty common.

02-10-2005, 04:07 PM
It is crap - mail the whole lathe to me and I will grudgingly take it off your hands - no, really I will! http://bbs.homeshopmachinist.net//biggrin.gif

02-10-2005, 08:15 PM
*ALL* leadscrews have some amount of backlash. It's a given. You have to account for it in use by always taking up the lost motion in the same direction. That is, if you are moving forward and overshoot your mark, you have to back up past the backlash and re-approach the mark you want from your original feed direction. 5 to 10 thou, even 15 thou, of backlash is fairly normal. You'll see even more on worn machinery. At some point it becomes annoying, but dealing with backlash is just part of knowing how to use a machine properly.

As nheng says, the nut might be adjustable. But don't fret too much if it isn't. Even if it is adjustable, you'll still have some backash even after you adjust it.