Triple D Diamond :: DDDiamond :: Direct Drive Diamond 3 Color Hotend for BMG Clone Extruder for MGN12 Linear Rail

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UPDATE: this entire setup weighs 931g. That’s including three pancake steppers, 23 mm thick, just over 100g each. This print weighs 101 and is sooo solid. The only fragile bit is the thin stepper plate. This is a hotend bracket for the Diamond 3-color. Since the three inputs are V6 hotends, I decided I'd like to see how this looks as a direct drive! This is designed to mount on this linear rail (I put a 400mm on the CR-10s and it fits nicely between the motor and the belt tensioner.: https://www.amazon.com/gp/product/B0762MKQFD/ Printing in PETG at 80% infill and 1.2 walls (2 passes on a .6 nozzle), this weighs just over 100k once the supports are removed (varies by material and density). So for screws and bowden tube inside the V6 and all fan and all that -- under 1kg for this. As heavy as that sounds, a set of dual Titan Aeros are about the same weight with 42mm steppers. Here are the 23mm steppers I used: https://www.amazon.com/gp/product/B07ZD144GG/ The attachment pattern is a 20mm x 4 M3 screw pattern for a MGN12 linear rail bracket. All nuts (BLtouch and fan) have embedded hex patterns inside the design, so no wrench should be needed, only a hex driver. I used this screw set, which includes various lengths and nuts: https://www.amazon.com/gp/product/B07J3J92H6/ Hey, Kev! Why the heck is this thing such a funny shape? I'm glad you asked. In order to cool the three V6 hotends, you need a fan blowing down the center However, the fan tower was blocking the screws in the front of the BMG, so assembly was a pain. I tapered it in a bit to a single smaller channel and then distributed it out at the bottom in order to make access to the screws on the front of the extruders. Furthermore, it's not easy taking a 1KG~ hotend and dangling it 70mm from the linear rail without getting a bit of wobble. I'm pretty happy with the amount of support beams and how solid this sits. Solidly? ASSEMBLY / DEPLOYMENT: For the PTFE tube, I used approx 35mm Bowden (about 35.4 max).-- I didn't get too precise and the filament still feeds well all the way in. Assembly is a bit tricky. I assembled all three extruders with the V6 inserted and all 3 screws inserted. I slid them down into place (without the diamond tip present). There's not enough room for the front face of the BMG to come off, but you can loosen it, allowing the V6 to spin. One by one, carefully spin the V6 to screw each end into the diamond. I did a little at a time, but there's a bit of flex and grace. This is a somewhat tedious process, so I'm sorry in advance. Once the three throats are into the diamond, there should be enough room to get a long hex screwdriver in. I have a set of these and absolutely love them: https://www.amazon.com/gp/product/B014ERIFU6 Again, the only reason for the hourglass-shaped center tube is to facilitate a screwdriver. It's still tight, but possible. After that, attach the BLTouch to the recessed bracket. I gave it a few extra MM of upward play. If you use the included springs, you shouldn't need spacer nuts. The final version of this has upward supports with two versions: Optional BLtouch bracket or one without all the supports and no BLtouch.