Mendel90 GT2 mod

thingiverse

GT2 Belt & Pulley Mod for Mendel90 by nophead This mod upgrades your Mendel90 printer's performance using GT2 belts and pulleys without a twist. The update on 09/08/2013 includes a y-axis tensioner for the dibond model. Here is what you need: - 2 x GT2 Pulley, 20 teeth, 5mm bore (http://www.robotdigg.com/product/9/GT2-Pulley-20-Teeth-5mm-Bore) - 2 x GT2 Pulley, 20 teeth, 8mm bore (http://www.robotdigg.com/product/23/GT2-Pulley-20-Teeth-8mm-Bore) - 663 mm + 903 mm GT2 belt (http://www.robotdigg.com/product/10/Open-Ended-6mm-Width-GT2-Belt) - 4 x M3, 4mm grub screws (http://www.robotdigg.com/product/17/M34-Grub-Screw-PACK-SET-for-Timing-Pulleys) - 4 x 608ZZ ball bearings (http://www.robotdigg.com/product/12/608ZZ-Ball-Bearing) - 1 x M8 cap screw x 60mm - 1 x M8 cap screw x 45mm - 2 x M8 nyloc nut - 2 x M8 washer - 2 x M3 nyloc nut - 2 x M3 cap screw x 40mm - 2 x M3 washer Instructions: 1. X-axis mod: Print Mendel90_gt2_x_axis.stl and follow these steps: + Remove raft and open bridge layer in ball bearing hole with a knife. + Open bridge layer for screw holes (4mm for M4, 3.3mm for M3 screw holes) with a drill. + Press fit bearings in x idler holder. + Put GT2 pulley with 8mm bore on M8 x 60 cap screw, teeths closer to the cap. Fix with grub screws. + Insert cap screw with pulley into ball bearings; put pulley on top of printed x idler holder. + Secure cap screw with washer and nyloc nut; adjust for easy rotation if needed. + Replace stepper motor pulley with GT2 5mm bore pulley. + Press fit GT2 x idler onto original x idler assembly and fix with M4 cap screw. + Insert GT2 belt without twist, secure with new clamps. + Adjust tension with tensioner on x carriage. 2. Y-axis mod: Print Mendel90_gt2_y_axis.stl and follow these steps: + Open bridge layers in ball bearing hole with a knife. + Clean up y idler. + Press fit bearings in y idler holder. + Push GT2 pulley into idler teeth; insert M8 x 45 cap screw, fix with washer and nyloc nut. + Insert two M3 nyloc nuts into bottom. + Remove both y rods, turn heated bed over. + Remove belt clamps and belt. + Insert GT2 belt through GT2 idler without twist; clamp to anchors with new GT2 clamps. + Replace stepper motor pulley with GT2 5mm bore pulley. + Mount GT2 idler with original screw, slightly tighten. + Mount y-axis tensioner and adjust belt tension/direction with two M3 cap screws. No firmware changes are needed. Note that you may hear clack sounds from the pulleys; temporarily fix this by adding painter tape around cap screws where the pulleys and bearings are. For a permanent solution, upgrade to an 8mm rod with two snap rings on both sides. If you only want a GT2 belt upgrade with a twist, you need two GT2 pulleys with 5mm bore, the GT2 belts, and the GT2 belt clamps.