Improved Z probe mount for the extruder carriage for those of us who can't mount on the back side of the carriage due to the new fan placement. Holds 12mm diameter induction proximity probe (plus new version for 18mm probe - but see notes!). Mount attaches via the two hex screws underneath that hold the extruder in place, and via extending the tie wrap location on the corner of the platform. A hole is provided on the extruder plate edge to firm it up by adding a tiny wood screw. Don't tighten the 2 hex screws until you make sure the mount is fully engaged to the extruder plate. Screw holes are slotted to allow you to do this. Use small screw on edge or mount will split. (UPDATE 5/13) VERY IMPORTANT - use one of the toothed washers that came with your probe inside the underside nut. This will help keep the probe from swiveling in the mount... or worse, the nut may slide off completely during a print.
Successfully deployed on 2014 Simple w/LCD using probe purchased from printrbot and v3 of "marlin inductive" firmware. M212 values were set at X0 Y0 Z-0.9. X and Y need to be zero or a "Probe off Bed" error will occur. Z may vary. My probe sits about 2mm above the tip of the extruder nozzle, and that value gave me very good results with a .32mm first layer.
Update 5/10 - Stick with V2 firmware, or Non-LCD firmware. To use V3 firmware (needed for LCD) - which is actually metal simple firmware - you'll need to add a y limit stop switch on the opposite side of the y carriage, or your extruder head will grind into the body of the printer and louse up your settings and your machine. Took a while to notice this simple difference between the new and old machine.
For gcode settings in repetier, be sure to add G29 command after G28 command in code header. Note - You may, as you cannot on a Metal Simple, home all values before the G29 autolevel with a regular G28. This will prevent a situation where, if your printer was left with the probe off the bed, it will autolevel and print in the air. Just make sure you have everything set up before you do this, and be ready to unplug the unit if your extruder drives into the plate. Note - you may want to still use "G28 X0 Y0" until your probe is within a reasonable range, or you may damage your machine by driving the extruder into the plate.
UPDATE: Added 18mm probe version on request. NOTE! This one is untested - I strongly suspect it may ram into bed screws, so exercise caution. Let me know if you try it and your results.
Print as oriented in new STL file. Printed w/all layers at .33 with supports. Tweak the Overhang threshold value to something small (10Â° worked for me) so that support only prints for undercarriage mount arm. All other parts print fine without supports. Use raft if you need to, but didn't have to. NOTE: Since you have to remove the existing tie-wrap to put this one on, make sure you have a replacement BEFORE you cut off the old one!
Sample on photo printed with Simple Metal.