Floating X mount Prusa i3

thingiverse

This is a remix of Auto touch Z end-stop.(https://www.thingiverse.com/thing:220709/) By Radus. I fell in love with the simplicity of this auto bed leveling feature. This mount allows the X axis to float freely, requiring two mounts, one for each side. The switches should be wired in series and firmware set to normally closed switches. When your print head hits the bed, the circuit will open and the firmware will record the height. Remember to adjust Z safe homing settings in Marlin since this setup will override your standard Z axis settings. Z_PROBE_OFFSET_FROM_EXTRUDER depends on the amount of backlash when the printer head strikes the bed. Unlike probe auto bed setups, this value is actually positive. Mine is set to 1.1. Start with a high value (higher than mine), do a first layer test print, and lower it until you achieve a nice first layer. Starting low might damage your printer. I incorporated a microswitch from a broken Onkyo receiver instead of the foil Radus used. Refer to the picture for measurements of the microswitch. I also created a mount for the original brass nut that comes with the Z axis on my printer, rather than using the standard nut that Radus employed. The holes for the wires to the microswitch are quite tight, so I used thin wires from an old LPT cable. An ethernet cable would be another suitable source for these thin wires. I designed this mount in Sketchup and uploaded the .skp file; feel free to remix! 2016-02-22: A new version has been uploaded that allows the microswitch to be mounted on either side of the Z-axis rod. As mentibump pointed out in a comment, this design is sensitive to differences in weight between the X-axis. I plan to convert my printer to bowden and use it with one extruder motor attached to the X-axis. See this thing: http://www.thingiverse.com/thing:938737