Hi I'm building a Sphinx style CNC and have problems attaching the pulley to the lead screw on Z. It simply seems to be loose. The first time I tried tightening it I overtightened it to the point where I stripped the threads on the clamping collar and had to order a new collar. Has anyone else experienced this? If so, do you have any solution? Thanks, Andreas
What I did on all collars was carefully take the bit used for my m3 tap and drilling into the rod through the hole the set screw would go into. Then I would tap the hole in the rod. I screwed a longer m3 screw through the threads in the collars and into the threads in the rod. None have ever come loose or slipped. I did something similar where the shaft couplers attach on both the threaded rod and the stepper shaft. Word of caution, it is very difficult to drill these holes with the possibility of breaking the bit.
That sounds like a well engineered solution. I do believe it is beyond my machining toolset (not to mention skill-set). I think I'll try adding some shims between the axis and the coupler...