For the intrepid adventurers who want to test this solution out themselves, here is everything you will need:
1x Printed x-carriage
1x Printed z-probe-mount
1x Printed up-down-bar
5x 2.5m x 12m socket head cap screws
1x 3m x 25m socket head cap screw
4x 3m washers
1x 3m nyloc nut
1x mechanical limit switch
2x 10mm x 5mm x 3mm neodymium magnets (ours came from a sonicare brush head)
- Print out the new x-carriage, z-probe-mount and up-down-bar.
- Press the magnets into the holes on the x-carriage.
- Attach the limit switch to the z-probe-mount with 2x 2.5m x 12 screws
- Attach the up-down-bar to the z-probe-mount with 2x 2.5m x 12 screws and put on nuts.
- Attach the z-probe-mount to the x-carriage with the 3m x 25 screws placing a washer after the screw head, between the carriage edge and the probe edge on both sides, and before the nyloc nut.
- Put the new mount on you mendel90.
- Drill a 2.2mm screw hole into your mendel90 frame, 9mm from the left inside cut out and 5mm above the bottom of the cut out. This will hold the raising and lowing pin.
- Insert one 2.5m x 12 screw into the raising and lowering pin hole.
- Hook up the z-probe switch to the z-min switch connection.
- Add a G29 to your slic3r custom g-code config just after the G28 (home all axis).
You will also need to configure the offset to the extruder in the firmware (Auto_Bed_Level branch) for you exact printer.
The offset of the z-probe can be found in configuration.h, starting at line 201 it looks like this:
define X_EXTRUDER_OFFSET_FROM_Z_PROBE 35
define Y_EXTRUDER_OFFSET_FROM_Z_PROBE -14
define Z_EXTRUDER_OFFSET_FROM_Z_PROBE 7.10
- You can calculate these values with this procedure:
- With the z height correctly set (this is just normal reprap step), position the extruder exactly on the bed
- Run a m114 and record the result
- Move the x and y (in proterface) to put the probe in the same x and y position the extrude is in then run a g30 (do a sigle probe)
- Run another m114 to find the probe position and height and record the result
- Subtract the first m114 from the second m114 and enter the values into the configuration.h
Currently this is only set up to work with RAMPS boards. If you have another board, you will have to get the z-bed switch working on the z-min switch for your printer. If you do, we would love to have your patch.