Autolevel Z-probe mount and arm for Velleman K8200 / 3Drag (5g servo)

thingiverse

Overview Designed to fit a microservo (5g) and position the probe (microswitch) closely to the hotend (E3D v6 on my mount in particular). The cutout for servo's arm is slightly undersized, requiring enlargening after printing or trimming the arm. Assembly To assemble, you'll need an M5x15 screw, M5 washer and square M5 nut for attaching the mount to the printer. Additionally, you'll require an M2x12 screw and M2 nut for attaching the servo to the mount, as well as two M3x12 screws and two M3 nuts for attaching the microswitch to the arm. Wiring For original K8200 controller, plug the probe's microswitch into the Z endstop socket. Wire the servo to the extension connector on the controller board: Black (or brown) -> GND, Red -> 5V, Yellow -> SS pin. If using a fan that occupies the GND pin, solder an additional header onto the back of the board for more manageable wire management. For other controllers, figure it out yourself; it should be simpler. Configuration To enable automatic bed leveling/trimming, you'll need Marlin in version 1.0.2 or newer (get it from here), as official K8200 software doesn't support this feature. For general tips and hints, recommend Thomas Sanladerer's great video. There are, however, differences in software used - see the 'Probe Z-distance calibration' section. Copy your old configuration: The best option is to open your current configuration.h and the new one side-by-side, then copy corresponding values, as the structure of the file has changed and new features that we'll use were added. Instead of hard-coding motherboard type value (77), you can use following code: #define MOTHERBOARD BOARD_3DRAG Enable autoleveling: First, find and uncomment line: #define ENABLE_AUTO_BED_LEVELING Then set up rectangle in which to probe, my recommended values (big margin for glass clamps): #define LEFT_PROBE_BED_POSITION 40 #define RIGHT_PROBE_BED_POSITION 160 #define BACK_PROBE_BED_POSITION 160 #define FRONT_PROBE_BED_POSITION 40 Lastly, set up position of probe relative to nozzle. X and Y offsets can be rough estimates, while Z offset will be fine-adjusted further on (see 'Probe Z-distance calibration' section). Values below are for E3Dv6 hotend mounted on my bracket and servo mount placed roughly 30mm from said bracket: #define X_PROBE_OFFSET_FROM_EXTRUDER -35 // X_probe > X_nozzle #define Y_PROBE_OFFSET_FROM_EXTRUDER 4 // Y_probe < Y_nozzle #define Z_PROBE_OFFSET_FROM_EXTRUDER -50 // Not calibrated! Don't print with this value! WARNING! Don't print with these settings, Z offset requires further tuning! Enable servo support: In pins.h add following code to line 736: #if MB(3DRAG) #define SERVO0_PIN 53 #endif This will enable servo support of SS pin of extension connector on the board. In configuration.h, find 'R/C SERVO support' section and uncomment and adjust the following settings: #define PROBE_SERVO_DEACTIVATION_DELAY 300 Save, compile, and upload. Probe Z-distance calibration: General procedure is the same as in Thomas Sanladerer's video, but due to slight differences in G-code there are minor differences. Start up the printer, connect with your host software, home all axes (Z must be last one), issue Z-probe G-code:G29, home X&Y axes, go to middle of your printbed, put a piece of paper on the printbed under hotend, and slowly lower your hotend until it just slightly holds the paper against printbed. Write down by how much you lowered your hotend! Example: 14.2 Open configuration.h once again and set value of probe's Z-offset: #define Z_PROBE_OFFSET_FROM_EXTRUDER 14.2 Save, compile, and upload once again. Slicer configuration: In custom G-code section (for Slic3r it's in 'Printer Settings') add G29 just after G28. Profit Print Settings Printer: Velleman K8200 Rafts: Doesn't Matter Supports: No Resolution: 0.2 Infill: 50 Notes: PLA