Bondtech BMG on a Taz 4 (or Taz 3-5--needs slight mod for Taz 6)

thingiverse

This is my Bondtech BMG with E3D V6 hotend mod for my Taz 4. I will also work on a Taz 3-5, and it will work on a Taz 6 but needs a minor mod to attach the +X limit switch. I'll get around to that eventually and include the new part when I have time. You might be able to glue or drill a hole to attach the limit switch until then. This setup is great, accurate and reliable, especially after my removable metal bed and precision bearing upgrades. I forgot to mention that I switched to 1.75mm filament, but I don't recall if the Bondtech BMG has a 3.0mm filament model. When printing the lower air duct, I did not use support inside of the duct itself; instead, I used some outside. Internal walls are designed to eliminate the need for support which would be difficult to remove. The duct on the extruder holder needs some internal support. Try to keep it to a minimum because it can be difficult to remove if you overdo it. Parts: Standard (not mirrored) Bondtech BMG E3d V6 hotend A 24V blower fan, which is actually a 12V version in the photo that runs fast. I have 24V ones on the way but this one works fine. A 5V 30mm fan for the hotend cooling fins. The duct comes with the E3D kit. Also a short hunk of PTFE tube to connect inside the Bondtech BMG I used a NEMA17 40mm length stepper. The BMG and E3D I ordered from 3DMakerworld. Note that the extruder mounting bracket has two plugs for the duct to the left of the BMG extruder. The bottom screw on the BMG needs to be tightened from the left side of the fan duct, and then the two plugs cover the hole for the 2.5mm hex wrench. The outside left plug is not a problem but the inner (right) plug requires some finesse. I used some fine needle nose pliers and a small flat blade screwdriver to coax it into the hole. A few M3 x 10-12mm screws and washers. Two M3 x18-20 screws and washers. I used four brass M3 inserts for the hotend blower fan and in the lower air duct to attach it to the extruder holder. I also included the mount for the 12mm inductive probe which I show here, but really that should be elsewhere because it requires a metal bed to work. If you do not have a metal bed or intend to use a probe to auto-level then just ignore the probe clamp. The interface between the air duct and the extruder holder duct should be clean and carefully fitted to prevent air leaks. You have to change your E-steps to about 455. I think that was the starting suggestion, and after calibrating, be extruding 100mm of filament a few times; I did not make any changes to the starting number. That change can be made from the LCD panel Control settings. Remember to save the settings afterwards so it persists. This can also be accomplished from a command line in Simplify3D, Slic3r/Pronterface, etc. I'll try to add some more photos later.