Tronxy P802D X Belt Tensioner - parametric

thingiverse

I completely rewrote this! 1. The belt alignment was slightly off, I couldn't move the pulley on the stepper any further forward without the belt rubbing against the front wall of its slot in the left Z-trolley, so I adjusted the axis of the cable pulley hanger a bit backwards, off-center. 2. Due to the big bearing (a 6x20x5) used for the right-hand pulley, there were some sticking and sizing issues on large jobs at the extreme-right end of the x-travel, so I swapped it out with a smaller pulley (same diameter as the gear pulley). 3. I made it open-ended for easier belt access and removal. After 10 huge prints (near 200mm wide), not a single problem occurred. The backing plate is the original from my first-ever tensioner. It's just a rectangle with a hole in the center. Cheers, "Crunchy" 2019/1/14 There are plenty of cheap Prusa i3 class TronXY printers on eBay, and very few of them have belt tensioners. Without belt tension, the quality from these machines is absolute garbage. This is my solution to the problem. Along with this part, you'll need a 40x12x3mm rectangle with a 3.2mm hole in the dead center for a backing plate, and an M3 x 35mm screw, washer, and nut. Put the M3 nut in the slot on my part, put the screw through the washer and backing plate, then place the backing plate against the right-hand side of the right-hand Z drive. Insert my part into the left-hand side of the right-hand z drive, so that the screw meets the hole in the tensioner, and threads into the nut. Use the bearing, M6 bolt, and nut as provided to install the pulley and belt. Tighten the back screw until the belt is moderately tensioned and run a few test prints to get the best quality with minimal "ringing" in the y travel faces of the test prints.