Kossel Mini carriage for MGN12

thingiverse

Added a probe for an optical endstop, re-enforced the backstop for the captured toothed belt and countersunk the four mounting bolt heads. WARNING: See Instructions. See http://www.thingiverse.com/thing:450238 for the matching optical endstop mount for Openbeam 15x15. Timelapse video: https://www.youtube.com/watch?v=VxSCTOD9BZQ Instructions PLA appears to have a relatively low absorption in the infra-red area of the electromagnetic spectrum. The 2mm thick probe which breaks the IR sensor in my endstops lets through most (>80%) of the IR LED's output. The visible indicator LED on the sensor board only dims slightly when the probe is in place, certainly not anywhere near enough to trigger a low logic level. My solution was to paint the probe with a small amount of black acrylic paint. Two coats over 5 minutes was sufficient to cause the indicator LED to turn off fully, though in practice the endstop is triggered while it is still dimly lit and the output voltage falls below the Arduino input pin's low logic level.