For the steps per mm, It was a little trial and error and a little math :-).
The diameter of the dowel was 1.125 inches I multiplied that by 3.14159 (pi) to get the circumference of the dowel, 3.534 inches.
I made a mark at the bit location, told the machine to move 3.534 inches to rotate the radial axis, if correct the axis should rotate 1 full turn and stop on the mark. I adjusted from there.
When I replace the electronics, once everything arrives, the calculations will be translated to degrees of movement for the axis, so I will have to play around with settings again.
But it is fun 