Advice please

[Greeny]

To get pinion to rotate 1 revolution the motor needs to turn 5 revolutions (90/18)
1600 pulses rotates motor 1 revolution.
So need 1600 x 5 = 8000 pulses for pinion to turn 1 rev.

Can't work out distance (D) travelled for 1 rev of pinion without more info.(Num teeth on pinion & rack mod if it's r&p)

Once you know distance travelled for 1 rev of pinion= D, then distance per pulse = D/8000

**Edit, seems you need pulses per mm so its 8000/D

Cheers