Orac Spindle Control and Z Axis Movement issues

[Brian_S]

Hi Guys,

I have just acquired an Orac CNC lathe, which is in very good condition. I've fixed a limit switch problem, but the Z-Axis had troubles moving. It would sometimes drive correctly on fast speed, sometimes drive in the wrong direction on fast speed, and have very eratic behaviour on slow speed.

Has anyone come across these symptoms? I have narrowed it down to the stepper driver board because I swapped the Z and X boards around and now the problem exists on the X axis. I will have to compare the boards if no-one has a direct pointer and see what is wrong with it.

My second problem is that the spindle seems a bit random, that is to say it will start with the speed at minimum, and then I can speed the spindle up, but most of the time I get to a speed where it cuts out. Sometimes it does and sometimes it doesn't. Generally if I try to start the spindle when it is set at quite a high speed the spindle starts to accelerate and then gives up. This is all while the lathe is in manual mode.

So, because of these two niggles I haven't had a chance to program anything yet which sucks because I am dying to get a program running!

Any advice or pointers would be gratefully received!

Best Regards,

Brian.

[Brian_S]

Hi Guys,

I finally tracked the stepper driver problem down to the 4516 IC on the half stepping board on the CD20 drive. So that problem is now solved.

The spindle speed was easily solved by putting another motor controller I had lying around in, it works great and is hooked up to the spindle control properly so works like a factory unit (albeit better at low speeds).

But alas my problems are not over, I now have a corrupt display, which looks like "shift" is constantly pressed, and any program I enter comes up with an error on every page (including things like mm/inch, etc.) I will put up another post about that though.