Mochaboy's "Tool less" Tensioner Printrbot Jr / XL and GT2 belts

thingiverse

Update 8/10 Added bracket for GT2 belts - Recommend printing that bracket at .2 layer height I had a few design goals for this part. Use parts available at Home Depot Be "tool less" Be non destructive to the fascia No more damn toothpicks The tensioner consists of a top belt catch, 2 14mm adjuster knobs, and a bottom captive plate/foot. You need: 4 x M4x30mm Hex Bolts (Home Depot small parts section) 4 x M4 nuts Some notes on assembly: 1) The skp files are dimensionally accurate +~.25mm. You can change them to suit your part or just print with 3-5% extra scaling. I printed my parts at 1.03 and 1.04 scaling and they came out "just right". 2) the channels for the M4 bolts in the top plate should be have very little play but the bolts should be able to slide through them effortlessly. If they're too tight - just ream them out with a drill bit. 3) the captive nuts should face the tensioner bottom/foot 4) The foot keeps the parts secure and protects the wood from marring 5) The bottom foot has a cavity cut out so it can sit on top of the cap screw :) I found that after about 50 hours on my printer, it needed a belt adjustment - the knobs make this effortless now :) Enjoy!