Nut for Linear stepping motor.

thingiverse

The previous Y-axis movement test was unsatisfactory; view the issue at this link: http://www.thingiverse.com/thing:106254. The problem involved a slow and noisy performance, coupled with non-straight lead screws. Additionally, the motor wiring was incorrect. To rectify these issues, I used a dial gauge to correct the lead screw's straightness and redesigned the lead screw nut, replacing backlash adjusting nuts as per this link: http://www.thingiverse.com/thing:98894. Marlin firmware and Cura were utilized for the movement test, with a 200.0 steps per unit value set in the configuration.h file for an 8mm lead screw and 1/8 micro-stepping condition. Manual Y-axis movement was carried out using Cura's jog buttons at a speed of 100 mm/sec, resulting in a better performance as demonstrated in this video: http://youtu.be/AMEa2v2D23w. However, the uploaded nut had a large tolerance, causing it to fit slightly tight against the lead screw due to Rep2's inability to produce an exact circle. The nut length was reduced from 25mm to 4mm to minimize friction and only one nut was used because backlash couldn't be felt with just one. Teflon oil was employed as lubricant, providing a smoother feel compared to WD-40. If you need a model with smaller tolerance, please let me know.