Archive for December 3rd, 2017

MPCNC: Z Axis Coupler Backlash Prevention

The MPCNC has the entire weight of the Z axis motor and stage resting on the leadscrew, so the instructions call for preloading the spring coupler by stretching it with the leadscrew butted against the motor shaft. The leadscrew end isn’t particularly flat, so I inserted a 1/4 inch ball bearing between the two before the stretch:

MPCNC - Z Axis leadscrew - coupler bearing

MPCNC – Z Axis leadscrew – coupler bearing

I’m reasonably sure the ball won’t make the slightest difference, but two slightly misaligned shafts can now pivot on a point, rather than grind against each other. There’s no evidence of misalignment; I feel better and that’s what counts.