Anti-wobble Z-coupling (for Mendel-Prusa)

thingiverse

I got obsessed with z-wobble in my MendelMax 1.5 recently and thought it was worth fixing to see if it would improve print quality. My printer's motor axis is very stable, but the lead screw itself is wobbling at the coupling location. Based on nophead/Griffin_Nicoll's design, I updated my model with adjustable asymmetry to minimize the effects of the z-wobble issue. The updated design allows for adjustment in a single direction and has some visual updates as well as additional length to enforce straightness. I decided to use m3 screws and bolts to improve durability and resistance to wobble. Here's what worked for me: 1. I moved my printer's head up and down with a straight coupling, then checked if the axis moves back and forth (observed from the side). 2. If so, I applied an asymmetric coupling in one direction with varying values, starting at around 0.3mm. Adjusting it to find the optimal value involved experimentation. Some users have experienced improvements by fine-tuning their values: 1. Straight on one end, asymmetrical by about 0.3 mm on the other end. 2. Rotate the coupling, and check if any improvement is noticeable. The most important part of optimizing the asymmetry for best performance can be tedious and takes patience