CNC machining operations require precise leadscrew movement to producing a good part. The normal backlash of .003" to .005" can be unacceptable in these situations and a way was needed to reduce backlash to the .001" to .002" range. This solution was developed for the Z-axis on the mill, but it has been adapted here to work on the lathe as well.
Sherline lathes have never been fitted with locking levers on the leadscrew. This system was developed specifically for use on CNC machines. The new retrofit installation kit includes a new locking lever and a new saddle nut without a spring loaded ball to hold it in the unlocked position. The positive locking arm allows partial locking of the lever to reduce backlash to a minimum. The small detent in the locking lever that was formerly used to engage a spring-loaded ball has been retained to indicate the side of the locking lever that should be facing the saddle nut. If the locking lever should fail to lock against the saddle nut within the available arc in the back of the mill column, check to see if the lever has been installed backwards.
Download PDF Assembly and Instruction Guide