Vertex K8400 GT2 belt upgrade tensioner

thingiverse

After six months of consistently producing high-quality prints with my Vertex K8400 printer, I encountered problems with print quality. To address this issue, I attempted to re-adjust and re-calibrate the printer, replacing belts and upgrading to GT2 belts. However, it was not until I discovered that the stepper motor had worn out that I realized the upgrade to GT2 belts was unnecessary. I created a GT2 belt fastener/adjuster to facilitate easy installation of the new belts. To use this component, you will need to print four copies and their mirrored counterparts. To accommodate the new GT2 pulleys, I made several modifications to my printer. Specifically, I removed one corner piece on the right-hand side to adjust the tension for the servo motor, and I cut away most of the bearing holder on the left-hand rear side because it interfered with the new pulley and belt. With these adjustments complete, everything functions smoothly, and I am satisfied with the print results. The last picture demonstrates the difference between my old prints and the new ones, making it clear that the one on the right is the old print and the one on the left is the new one. To ensure secure installation of the pulleys, apply Locktite 243 to lock the pulley screws in place. This will keep them tight but still allow for easy adjustment if needed. Print Settings: Printer: Vertex K8400 Rafts: Doesn't Matter Supports: No Resolution: .1 mm Infill: 10% Post-Printing: Changes to the Printer Configuration Since GT2 pulleys have a different diameter than original T2.5 pulleys, the firmware needs to be modified. To make this change, locate and modify the Marlin code in the Configuration.h file. Replace the line #define DEFAULT_AXIS_STEPS_PER_UNIT {134.74,134.74,4266.66,200} with #define DEFAULT_AXIS_STEPS_PER_UNIT {160.88,160.88,4266.66,200}. You may need to adjust these values after making a test print. My measurement of a first test print of a 20mm box was 20.2 mm, indicating that the value of 160.88 should be decreased by 1% to 159.27. To upgrade the firmware, follow the instructions at http://manuals.velleman.eu/article.php?id=31.