What's new
What's new

Leadscrew Center Nut

Not open for further replies.


Jan 3, 2007
N. Virginia
My Y leadscrew has a center nut unit. This is a housing that clamps tight 2 brass nuts separated by a spring. I took measurements of the stick-out on each side of the clamp for the 2 threaded nuts.

I could reassemble with the same settings. Or just allow the spring to push the 2 nuts apart while on the leadscrew.

The nut unit is located under the table and not accessible when the Y-axis table is assembled on the carriage.

Yes there was backlash on this, don't remember exactly but say 0.020".

Yeah, what are you asking? Your description sounds like a backlash eliminator. Typically, you unlock the device and let it take out the slack, then relock the device. It's not magic, though. If you have uneven wear on the screw, you better take out the slack on an fairly unworn portion of the screw and just learn to live with the slop on the heavily work portion. Usually these are set up so the split nut takes the wear, leaving the screw in good condition.
Last edited:
I was asking what you told me, "unlock the device and let it take out the slack, then relock the device". I wasn't sure if there was more to it than that. The screw is fine and the nuts are pretty good, so back together it goes.

Thanks for the info.
Not open for further replies.