UPDATE 2019-11-10: By request added a version with a BLTouch mount. I don't personally own a BLTouch so I went off the dimensions at https://youprintin3d.de/media/pdf/54/75/b4/f5a1c8_77037f55e5d542309d9fc178165c9f3f.pdf. For this mount the X offset is -29 and the Y offset is 0.
UPDATE 2019-10-26: Added a new cooling duct with a completely different design. This duct is giving me even better results - I'm seeing almost perfect 70 degree overhangs at 0.2mm layer height, and even 80 degree overhangs are not absolutely awful. See part NewPartCoolingDuct.
Also added V2 of the WireLoomAdapter - this helps keep the wires away from the extruder gear.
UPDATE 2019-18-8: Added a new V2 version of the part cooling duct - this aims the air a few mm higher and at a shallower angle and is giving me better printing results.
This is an X carriage to hold a Bondtech BMG extruder and E3D V6 hotend in a direct-drive configuration on the BLV mgn12 3D Printer mod for Anet A8 / AM8 / Prusa I3 clone. It includes a holder for an 18mm inductive/capacitive sensor.
Also included are adapters for 1/2" ID (approximately 18mm OD) split wire loom for cable management, as well as a part cooling duct.
The part cooling duct is inspired by Semi-Circular Anet A8 Fan Duct (although it was modeled from scratch), and the wire loom adapter on the X motor end is based on the one from BLV mgn12 3D Printer mod for Anet A8 / AM8 / Prusa I3 clone (although again modeled from scratch).
#define X_PROBE_OFFSET_FROM_EXTRUDER -38
#define Y_PROBE_OFFSET_FROM_EXTRUDER -24
Anet A8 with BLV MGN12 upgrade
3D Solutech PETG
All parts except for the cooling duct are printed at 0.2mm with 5 perimeters, 50% cubic infill for strength, with supports everywhere. The WireLoomAdapter was printed in the orientation shown in the STL with supports and a brim.
The PartCoolingDuct is printed at 0.1mm layer height with no infill, no supports, no brim.
Clean off supports. Put 4 M3x8 screws in the holes to attach to the MGN12C block, but do not attach it to the carriage yet. Use 2 M3x20 screws with part X_screw_holder from BLV mgn12 for the X belt attachment.
Place M3 nuts in the provided openings to allow attaching the part cooling fan and wire loom adapter on the main carriage.
Assemble the BMG extruder and V6 together, do not install the heater cartridge until you pass the V6 through the hole in the bottom of the carriage. Ensure that the V6 heater block is rotated as shown in the pictures, then insert the 3 long screws included with the BMG and tighten them to the extruder motor.
Attach the carriage to the MGN12C block with the 4 screws you inserted earlier. Add the fan, cooling duct, and cable loom holder.
Add the heater cartridge and the inductive/capacitive sensor.
Insert the cables through the slot in the cable holder, use zip ties as needed. Add the 1/2" ID split cable loom.