Lead-screw Conversion
Last updated on Saturday, September 03, 2011 08:22:30 AM Eastern US Time Zone

Lead Screws, Split Nut, Stepper Motor Couplers

Converted a mill's 3 lead screw, nut, & bearing assemblies to those for CNC & NEMA 23 motor mounts.

Lead Screws

The Taig CNC conversion kit: lead screws with bearings & bosses, adjustable bronze nuts, couplers, &
NEMA 23 stepper-motor mounts. The nylon tubing is cut diagonally (45°) into ¾" long coupling pins.
There are 4 pins per coupler. The diagonal cuts can assist in assembly.

Leftover parts from the conversion provided a precision ground ½-20 left-hand lead screw with bearing plate &
bronze nut assembly thus allowing the implementation of a very useful upgrade to the 9x20 lathe cross slide.

The NEMA 23 motor mount screws onto the finely threaded boss & is clamped into place by a ring & setscrew.
The bronze, zero-backlash nuts have two (outside) clamping screws & one (center) locking setscrew.

Split Nut

X-axis install. The bronze split-nuts work much better than expected. White lithium grease is a good lubricant.

Stepper Motor Couplers


X-axis boss & coupler. Do not over tighten the lock nut as it can bind (break) the bearings that are inside the boss.

Y-axis boss & coupler. Note the four holes for the ¾" long nylon coupling pins. A simple yet effective coupler.

Z-axis boss & coupler.

X, Y, & Z-axes lead screws now converted for CNC.

Lead Screws, Split Nut, Stepper Motor Couplers