Member postings for Zane Palmer

I have a Myford Super 7 with the power cross slide. I added an imperial gearbox and all seemed to be working well.

I then did the stupid thing of trying to do too much at once and ran the saddle into the end of the lath at the tailstock end and jammed it really good. I managed to get it loose and sorted out. There seemed to be very little noticeable damaged which appeared to be mainly paintwork scratches and a little adjustment of the leadscrew.

Later I tried to cut some thread and found that the pitch of the thread varied and it would not take a nut. The nut would travel a short distance of around 3mm and then stop.

I then did a test of just running the lathe on feed cutting a piece of brass. Then I could see that the saddle would travel at the correct rate, slow down, the correct rate, slow down etc. There were lines on the surface where you could see that the tool had spent more time on the surface. I measured the distance between each line and it was 1/8^th of an inch. This I think is the same as the pitch on the leadscrew.

I have checked the leadscrew and it is not bent and it does not move notably from left to right. I stripped the saddle and checked the ½ nut. That seems to be okay. I removed the power cross feed workings and still the lines remain. When I manually turn the leadscrew it seems to have no areas of resistance. I opened the cover to the gear box and it seems to be okay.

I am now at a loss! Any ideas on what the trouble could be