Jonathan,
I think I will have to try it that way to get it right. I had thought the pitch was 5mm but the distance travelled is not correct. I was hoping to be be able to turn the drive 1 turn and measure the distance travelled which would have given me my pitch.

antsals,
usbcnc seems to be very good but I have only started using it. The only thing I have found so far that I dont like is that the X and Y axis controls in the jog pad are the wrong way round from what I am used to. X goes from left to right and Y is up and down. I havent found a way to change this yet.