...

• Please see included STEP file where the individual parts go.
• The wheels are attached with 6mm spacers, with standard spacers on one side and eccentric spacers on the other side of the sled. The eccentric spacers can be used to increase the force the wheels press onto the beams.
• The lasercut holes in the aluminium plates are often too small. Drill them out to have the right sizes so that the screws go through. The only exception are 4 holes in the bed plate:
  
  These holes need an M3 thread to be cut into. Use M3x5 screws to bolt the upper sled plate to the bed plate using these threaded holes.
• The 8mm shims (12x8x1mm) are not shown in the STEP file. The shims go onto the lead screws between the lock collars and the ball bearings.

Firmware

We are running an enhanced version of GRBL with the XY table, called GRBL-Advanced. It runs on a STM32F411RE / STM32F446RE Nucleo Board and offers backlash compensation to archive better precision.

You can find the Github repository with our fork here: https://github.com/Laser4DIY/GRBL-Advanced

Results

We measured around 0,05mm of backlash for the XY table in both directions. But with the backlash compensation feature, some impressive results are archivable. Here is an example engraving done with our Laser4DIY machine:

Image AddedImage Added

Please note that letters are not a single line, the outlines are engraved.

Here is a microscope shot of an engraving with a font ~0.5mm high:

Image Added

...

Copyright FabLab München e.V. 2021

...