Quote Originally Posted by Jonathan View Post
Measure how far the axis moves. So for example on X move the gantry to one end, then turn 20 turns (or whatever) and measure how far it moved. You don't need access to the screw.

The meter you have will be fine. Just connect the negative probe to negative, (i.e. ground) and the other one to the correct pins. You may have to unscrew the board to access one of them.
Access to the chips wasn't too bad - off all three I got a reading of between 2.2 and 2.3 and occassionally -2.2 & -2.3 but I'd say that's my multimeter playing silly buggers.

As for turns per 20 on the X gave me 80mm, 10 on the Z gave me 40mm (couldn't turn it 20) and 20 on the Y gave me 62mm