BQ Prusa i3 Hephestos Autolevel (no servo needed)

thingiverse

What is it good for? Its a new autolevel mechanism I made for my BQ Prusa i3 Hephestos, but it should fit on other printers too. Unless other autolevel solutions, no probing servo is needed. Also there is no probe offset for x and y and very little for z and you only need to print one part, if you reuse some parts of your printer. How it works In normal operation, the 2 wires of the z endstop touch the upper linear ball bearing, doing a shortcut. If the extruder tip is hitting the glass base, the 2 wires of the endstop lose electrical contact to the upper ball bearing and the z endstop triggers. Disadvantages The x-axis belt minimally gets stretched every time the z endstop gets triggered. About half of the extruder weight (depending on the leverage effect) will rest on the glass base, every time before the z endstop gets triggered. What you need 3D printer Mechanical endstop (reuse your old z-endstop or make a new one. See notes below.) 2x M3 nut 2x M3x25 screw What you need to know How to compile and flash the 3D printer firmware! Print Settings Printer: Prusa i3 Rafts: No Resolution: min. 0.2mm Infill: standard PLA Post-Printing The Mechanical Part Print the part See section "endstop" Unmount the old carriage for x-axis Reuse the linear ball bearings and press two in the newly printed part Mount the new part Strip and solder the two ends of the wires from the endstop and put it through the endstop wire duct, until the cable coating is even with inner surface of the printed part. Bend the two wire ends downwards until they touch the inner surface. If necessary, use glue so that the wires don't get pushed out. Now bring the third linear ball bearing in place, so it touches the two wires and shorts them. The Firmware Part Edit your Configuration.h const bool Z_MIN_ENDSTOP_INVERTING = false; const bool Z_PROBE_ENDSTOP_INVERTING = false; (only needed with new Marlin firmware. If it's not set in your config file, skip it.) #define ENABLE_AUTO_BED_LEVELING (uncomment this line) #define Z_PROBE_OFFSET_FROM_EXTRUDER -0.5 (you need to figure out that value for yourself. -0.5 is a good point to start) Compile and upload firmware to your printer. For Cura: add G29 between G28 Z0 and G1 Z15.0 in gcode.start Endstop Make your own http://reprap.org/wiki/Mechanical_Endstop Solder the 2 wires to "SIGNAL" (2) and "GND" (1) Reuse Desolder the mechanical switch and solder one wire to "COM" and one to "NO".