Anet A8 3DTouch/BLTouch Auto Leveling Sensor Bracket

thingiverse

Update 30-APR-2017: I added the config file that people have been asking for. The configuration enclosed is the original 5 button configuration file of SkynetV2.3.1 modified to support 3DTouch/BLTouch. Note that this is for SkynetV2.3.1. --- End of update --- The 3DTouch/BLTouch sensor is a servo-based sensor. Its main advantage is that it allows you to easily switch between printing on glass or directly on the bed without having to adjust auto-leveling parameters. This sensor requires an additional pin that's not easily available on the Anet V1/Sanguinololu control board. To use this sensor on an Anet A8, you either have to move to a different board, modify the LCD cabling (see http://www.thingiverse.com/thing:2091529), or free up a pin on the Anet board by converting the display to I2C. See my design for freeing up a pin: http://www.thingiverse.com/thing:2098646. There are several 3DTouch brackets available on Thingiverse, but most won't fit the Anet A8. The one that might work (http://www.thingiverse.com/thing:2084025) moves the sensor so it's almost in line with the fan and right next to the extruder cooling fins. This limits the bed area available to the probe in the Y direction. My design will only work on Anet A8s with the same hole pattern on the extruder carriage as mine. This is a very tight fit, but it should not touch anything and is greater than the manufacturer's minimum suggested distance of 15mm from the hot end/nozzle. Prints: SensorBracket.stl, AlignmentSpacer.stl I printed both at 100% fill, 0.1mm, support "Touching Bed". I'm not a print settings expert, but I figured the bracket needs to be as rigid as possible. The alignment spacer is the distance from the base of the sensor to the bed when the nozzle is a paper thickness above the bed. The spacer is only as precise as your printer. Mine was spot on (today). It should measure 8.3mm on a good day. Mount the sensor on the bracket before attaching the bracket to the extruder carriage. Use Repetier-Host, Cura, etc., to place the nozzle the thickness of a sheet of paper off the bed. Use the alignment widget to set the height of the sensor above the bed. Some of the Marlin/SkynetV2.3.1 Configuration.h settings: I determined these two offsets using the grid file "Coords mm.pdf" define X_PROBE_OFFSET_FROM_EXTRUDER 59 // X offset: -left +right [of the nozzle] define Y_PROBE_OFFSET_FROM_EXTRUDER 14 // Y offset: -front +behind [the nozzle] The Z_PROBE_OFFSET_FROM_EXTRUDER setting should be set based on your actual results you measure during setup. define LEFT_PROBE_BED_POSITION 15 define RIGHT_PROBE_BED_POSITION 195 define BACK_PROBE_BED_POSITION 205 define FRONT_PROBE_BED_POSITION 25 If you use a non-standard servo pin, you'll need to define SERVO0_PIN. In my case, it's 27. define SERVO0_PIN 27 DO NOT attempt to do an Auto Home after your very first upload. Send one of the test gcodes to make sure you're connected. M280 P0 S10 ; pushes the pin down M280 P0 S90 ; pulls the pin up M280 P0 S120 ; Self-test – keeps going until you do pin up/down or release alarm M280 P0 S160 ; Release alarm Hardware: (2) M3 x 8, (2) M3 x 12, (4) M3 nuts