fickle y-axis

Hi,

Using DeskWinNC, Camtronics 2A driver, 33VDC power supply, I was
getting only 16-18 ipm previously.

Happy to report that after changing to a Pentium 4 and DeskCNC (with
the same old controller board) I managed to squeeze 35 ipm from the x-
axis before stalling. For the z-axis, I could get 17 ipm.

However, the y-axis seem to be acting up. At one stage, I could only
get it to make noise without any movement. After powering off, trying
another day, it was OK again. Now the y-axis can't seem to make up
its mind whether to move forward or backward. In MDI
G91 G01 Y0.1 F10
it is supposed to move forward (same direction) each time it is
activated. But what is happening is, sometimes it move forward, other
times it move backward.

DeskCNC uses a serial cable from PC to controller board, and parallel
cable from controller board to driver. So I try to see if I can
isolate the problem. I switched to TurboCNC which uses a parallel
cable direct from PC to driver. Same problem.

What could be the possible cause? Where should I start looking to
solve the problem?


Looks like a lot more work to get a consistent dependable system
going.
Thanks

Peter