My first test after assembling the board was to connect one motor to each axis in turn and test using Windows XP SP2 and Mach3. The test involved going to the motor tuning section and pressing the up and down arrows.

On the X and Y axis it was clear that steps were being lost. I had to turn the settings down to the lowest speed and even then there was the occasional loss of a step.

On the Z axis however the shaft only twitched. With identical settings to the X and Y axis it would not spin. So, the conclusion I drew was that there is a board problem with the Z axis.

Now I am testing with EMC2 running on Linux. My first test showed that all three axis, X, Y and Z appear to work just fine. The shaft spins quite happily on the Z axis…

So the moral of the story is that if one axis behaves differently it could be Windows causing it and not the board.

If you are stuck with Windows probably the only ways to determine where the problem lies are to either use a modified cable to swap pins around (so the problem axis is controlled by the pins for another axis) or to switch to TurboCNC and try that (perhaps with FreeDOS).