Half Nut Adjustments?

[Wongster]

Hello folks,

I spent the morning before heading to church stripping the lead screw, carriage, and the apron apart. Beside wanting to make some adjustments to the gibs and slides to make the axes turn smoother, I also wanted to take a look at how the half nut works.

You see, I've been seeing the lead screw being lifted up everytime the half nut is engaged and wonder if this is the cause of the lead screw handwheel not being able to turn smoothly. So the plan was to adjust the gib plate underneath the carriage so that it glide smoothly on the ways and put the apron back on to isolate the problem.

After spending quite a long time, I managed to get the carriage gliding smoothly with no lifting and side movement. When the apron was put back and half nut engaged, turning the handwheel is still a pain.

I'm unable to strip the half nut as it seems that the 4 pins on it are holding it down very tightly on the apron. When I look at the exploded diagram in the manual, I don't see anything that can be adjusted. The idea I had was to "move" the half nut up a little so that it is in line with the lead screw and so ease off the friction. I may have think wrong though...

Here is the exploded diagram from the lathe's manual:



Using Babel Fish, I've listed out the terms used:
P/N
36 - Klemmmutter: Clamping Nut
37 - Blech: Sheet Metal
38 - Nocke: Cam
56 - Stift: Pin
57 - Madenschraube: Set-Screw

The pics from this morning session can be found on my blog here

Before going on to making the ER32 collet chuck, I wish to get this arm-cramping-hard-turning of the handwheel out of my life.

Any help would be very much appreciated.

Regards,
Wong