Easy Print/No Supports - BMG Direct Drive for Ender 3

thingiverse

My first public submission. I hope it helps someone. This is a direct drive adapter for the BMG Extruder with Ender 3 type mounting plates. I made it because I wasn't completely happy with the other adapters that I saw or tried. Design goals: - No supports: other designs required supports over large areas and/or required printing in a non-optimal orientation. My design just prints flat on its back and is an extremely easy print. - *Very* stiff: I tried a couple of designs that flexed where the v-wheels connect because the holes for the plugs were too large. I also encountered designs that had very thin walls so the entire structure would flex. This was especially noticeable during retraction when I could see the entire direct drive assembly rock up and down. My design Does. Not. Flex. :-) - BL Touch clearance: There is enough space to the left of the fan shroud to allow many of the popular BL Touch brackets. Negatives: - Tight fit: Getting the motor and BMG to mate is a little fiddly. Just wiggle the motor around until the gears eventually slide in smoothly. It won't fit perfectly immediately. This was intentional to keep everything stiff but it takes a few tries. - Weight: This mount weighs about 34g which is 6 to 10g more than lighter designs. I think it is worth it for all the positives. I also believe that there are places which weight can be saved without sacrificing my main goals. But, you have to start somewhere and "a shipping product is better than a perfect product." Notes: - The mount between the motor and extruder is thicker than many designs. This contributes to the stiffness but means the screws don't set as deeply. So, be *very* careful to not over tighten your motor mounting screws so you don't strip the threads in the motor. Been there, done that. You've been warned. - My "BMG" Extruder is a clone that I received for review purposes. My understanding is that the dimensions are identical but I do not have an original BMG to compare to. If you have any experiences here, please let community know. History: - 21 January 2021: First submission