Vertex K8400 Pulley and Belt Replacement

thingiverse

After experiencing issues with Vertex K8400 printer's original T2.5/T19 pulleys, I decided to replace them with more commonly used GT20 pulleys and GT2 belts. To perform this modification, you will need the following parts: Two GT2 6mm wide belt rings with length 180mm (90 teeth) About 3.5 meters of GT2 6mm timing belt Ten GT20 pulleys with 8mm bore Two GT20 pulleys with 5mm bore (for motors) Four spring belt tensioners One M4 or M5 countersunk (flat) screw and self-locking nut for it The parts from the list above are available online. You will also need to print four copies of belt_holders thing and a single copy of each motor mount. I am posting images that show the placement and orientation of the pulleys. UPDATE 19-Feb-2017 My new post Print-head Mount Redesign contains improved belt clamps. Print Settings Printer Brand: RepRap Printer: VERTEX K8400 Rafts: No Supports: No Notes: Print settings for motor_mounts: Brim: 0.2mm Support everywhere Infill 50% Print settings for belt holder: Brim: 0.1mm No Support Infill 95% Post-Printing Additional Notes You will need to file down the upper part of AXIAL BEARING CLAMP mounted to the rear wall of the printer (above Y-axis motor) and replace its upper screw with countersunk screw (see image). This is required to clear space for the rear left pulley. New pulleys have slightly smaller diameter than original ones, so X and Y motors need to be attached via modified mounts, which place them lower than original position. My belt tensioner will help you to tighten motor belts. When mounting long belts, replace original belt clamps with new clamps posted here. The belt ends should be placed between 2 clamp pieces with teeth facing the bigger piece. This carriage alignment things are very handy when doing final adjustments. Firmware update You will need to modify one line in configuration.h file and then update printer firmware. See define command on image below. If you installed my wire covers, you will probably need to file down x_motor_extr1 piece or replace it with x_motor_extr1_rev2. Does it worth the effort? I think it definitely does. The quality of prints is much better. If old minimal linear step length was 0.00742mm, new value is 0.00625mm (about 16% improvement). GT2 belts with round teeth are considered a better fit for 3d printing applications comparing to T2.5 belts with rectangular teeth. And finally, the maintenance cost down the road will be much lower since original parts are more expensive and harder to find.