Sunday, July 6, 2014

3D Printer Mini-Update

This project is still alive! The printer was coming together nicely until I had to pack it up in preparation for graduation. I've since resumed work and the final bits and pieces are all falling into place.

The highlights of the past week:

  • All wiring has been completed. This includes connectors for ease of maintenance, heatshrink to prevent shorts, zip-ties to bundle groups together, and braided PET sleeving on exposed wiring for cosmetic purposes.
  • The Z smooth rods are now adequately anchored at the bottom. In conjunction with the mid plate, the rods are now completely stable. This was a critical improvement as the long Z axis would significantly amplify any error due to rod wiggle.
  • Auto bed leveling functions as intended! Some of the software configuration took longer than expected due to inconsistencies in documentation. I suspect when ABL was incorporated into Marlin, some things were tweaked and the material I referenced was longer up to date.
Challenges of the past week:
  • The printed ABS mounts I made to carry the Y-axis linear rail were not rigid enough to counter the racking forces introduced by the H-gantry. This resulted in a few mm of error every time the Y-axis changed direction. Printing like this would result in parts skewed at a 45 degree angle. Options to correct this include switching to the "CoreXY" system, or creating a new, more rigid mount. I chose to go with the latter by making a mount from angle iron and flat steel bar. This does add some weight to the carriage, we'll see how that translates into performance soon...
  • While tightening the belts for a test, I snapped off the belt mount. I've since changed the model to have much stronger supports, and was able to get the part printed locally.