Planetary drive based z axis for core xy printers

thingiverse

I originally modified the v-king z axis components to support a planetary drive motor: https://www.thingiverse.com/thing:3396656 but have since evolved that design to simplify the parts, use f695zz based idlers and include a belt tensioner as it was incredibly painful to get consistent belt tension in the original design. To assembly, print the parts (the belt clip covers are optional, I never bothered installing them and the belts as not moving) and then you'll need to build the idler and build the belt clip. To build the idler: * press f695zz bearings into the openings on both sides of the idler * pass a M5 smooth rod (or you use a M5 screw, but it's not quite as smooth) through the first bearing, a 1mm precision spacer from openbuilds.com, a gt2 toothed idler with 5mm bore, another 1mm precision spacer and the last bearing * tighten the grub screws onto the rod then build the belt clip: * insert a nut in the slot of the "belt clip" * thread a long M3 screw into the nut and the "adjustable belt clip" (obviously sliding it into the dovetail opening of the belt clip) Run the belts from the fixed idler, down to the motor, up to the idler and to the adjustable side of the belt clip. Clip both ends of the belt into the ends of the belt clip. Tighten the M3 screw to set the desired tension. I used this planetary gear motor with a 27:1 gear ratio: https://www.amazon.com/gp/product/B00QEUZ9EM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I am using 4 of these motors on my current printer design but 3 easily held a 350x400x8mm aluminum print bed with glass on top of that. I believe 2 would hold it but I'm not sure I've tested only 2 motors with the current design.