Backlash is most commonly created by cutting the teeth deeper into the gears than the ideal depth. Another way of introducing backlash is by increasing the center distances between the gears. Standard practice is to make allowance for half the backlash in the tooth thickness of each gear.

What is backlash and how is it measured?

Gear backlash is the play between teeth measured at the pitch circle. It is the distance between the involutes of the mating gear teeth, as illustrated in Figure 39.17.

Why is backlash bad?

Backlash creates an issue in positioning when an axis changes direction. The slack in the threads/gears cause measureable error in axis positioning. The MachMotion software can compensate a small amount for this error and better track the true position.