Hi Chip,
OK, I found the info sheet that came with the Xylotex steppers and drive box. It says,"
The STEP impulse must be an ACTIVE HIGH signal. The DIR line must be stable 200 nanoseconds BEFORE AND AFTER the rising edge of the STEP line. The STEP signal should be high for a minimum of 2 nanoseconds." (capitals theirs). It also goes on to specify the step and dir pins, which I have correct.
So, with that in mind, what I did was enable the Sherline pulse, make sure I had the other stuff correct, and try the steppers. No change.
I don't know what the info sheet means about the dir line being stable 200 nanoseconds before and after, etc., and I don't know if there's a setting for that, but one thing to remember is that everything worked perfectly yesterday, and I made no changes to the pins/dirs/low actives, or anything else. It ran a program, finished, returned home when I clicked on Go To Z, and then started acting up when I tried to jog the z axis up.
Still baffled, Bob