There is a possibility that locking the nut in place may cause binding at some point in the travel. If you do lock it be prepared to have to start fixing other things as well.

One place where a cheap design causes backlash is the mounting of the leadscrew to the machine bed. This can be checked with a mag base on the top of the bed with an indicator against the leadscrew end face. As you wind it left and right the ideal would be very little change in the indicator reading. A big change shows it needs a bit of fettling. There are articles on-line of people tackling this issue if you need ideas.

RF30 leadscrew fix for example, not the same as your mill but a fix for a possible source of backlash.

Martin C

Edited By Martin Connelly on 28/06/2021 19:01:02

You could try a layer of PVC tape to take up the slack, then see if anything binds before you resort to glue.

For completeness, is that not shown in the parts diagram – or did you just miss it while looking for something else?

Hi Tom, I have a Chester 626 and the manual is pretty dismal. Grizzly sell essentially the same machine in America and they do a much better one, there is a link to it in this thread: 626 thread

William.

Easy to miss, I expect, with so many reports on the dismal quality of some chinese translated instructions. Even the instruction manual for my 1960s English-built lathe is poor – there is more info in the previous model instruction book.

If the screw has been missing while in operation, the nut could be worn/damaged – particularly if the machine had been used for ‘climb milling’.