trying to set up bCNC

[DerFarm]

I have successfully wired the motors so that they run ... and run ... and run until I either click on stop or the bCNC just gives up and says the world is coming to an end.

One of the things I need (I think) is to set $100,101 and 102. If I'm reading it correctly, this tells GRBL how many steps it takes to one mm. The equation is: Steps/mm = (Steps per Revolution)*(Microsteps) / (mm per Revolution)
(http://www.diymachining.com/downloads/G ... _Rev_B.pdf).

From the people who sold me the motors:
1) Z will move 12.7mm per revolution (200 steps), X and Y will move 29.263mm per revolution (200 steps).

I have my external drivers set to 800 steps/rev. If I'm doing it correctly this would be:
800/29.263 = 26.999... Essentially, 27 steps for one mm on X and Y.
800/12.7 = 62.99... 63 steps for one mm on Z

This seems weird. Is this correct?