The Mi3

thingiverse

First off: Huge thanks to pheneeny for his AM8 design and inspiration. I actually bought an A8 just to upgrade it, back in July of last year. Then, major credit goes to BLV for his MGN12 upgrade. As he said, "Why not?" The linear rails make all the difference, in my opinion. And thirdly, I'm grateful to Paul Cole, who kindly shared with me a ton of info about his Mega and dual Z stepper functionality. Thanks again! UPDATE: I've added Z-axis pillow blocks to isolate the Z lead screws from their motors. Check out Thing https://www.thingiverse.com/thing:3933127 for details. Well, the only A8 parts in this printer are the motors, their wire harnesses, and a burnt-out hot bed serving as a plate for a stick-on heating element. It's running on RAMPS 1.6, with TMC2208s, and Marlin 1.1.9. So it's not an AM8, but it does have the BLV MGN characteristics. But I believe that's about all. I printed most of the parts for this printer on my Maker Select V2. Once the Mi3 was functional, I printed the last few cover parts on it. I haven't included any STLs or design files, but if anyone is interested in anything, please post a comment and I'll see what I can do. It was all done in SolidWorks. When I started this project, my goal was to keep it as clean as possible, meaning: no visible wires. A wire harness/bundle made to look good, yes, but not wires. The printer frame is 2040 and 2020 aluminum extrusion from Misumi, but it's mostly all covered by plastic cover plates. I didn't like the color of the so-called "black anodized." It looked more like brown to me, hence the covers. They all snap on/off. The frame is all tapped, drilled, and assembled using M5 x 25mm socket head capscrews. The ONLY bracing it has is the 2 gantry supports: no other corner bracketry or bracing of any type is used or needed. I pick it up by the top cross-rail and carry it. It weighs 39 lbs. I changed the top cross-rail to a 2020 and ran it across the tops of the gantry verticals. That gave me back a whole lot more vertical space for taller parts. The entire printer sits on a plastic support frame, which is surrounded by a plastic decorative shroud. The support frame has 3 4010 Noctua exhaust fans to get rid of the heat. There's a sheet of plexiglass between the printer and the support frame, so nothing falls into the visible underbelly. The printer then screws down to the support frame in the 4 corners under the snap-on covers. I put all the electronics in a drawer just to get them OFF the printer and out of sight. All wiring easily unplugs/attaches. The Y plate uses 3 carriage blocks: 2 on one side and 1 on the other. The hot bed is mounted on 3 points opposite the plate and locked with locking thumbwheels. The Z axis is managed/driven by independent Z motors and end stop switches utilizing the dual stepper feature in Marlin to auto level the X at the start of every print automatically. Those of you who own an AnyCubic i3 Mega (maybe others) know just what I'm talking about. The hot bed is a self-adhesive from GulfCoast Robotics, and the cable chain rides on the plexi separator sheet to the rear and down into the drawer. The extruder is an exact clone of the upgraded DD extruder I have on my Maker Select V2. Micro Swiss everything, all metal, hardened .04 nozzle, screw-in thermistor, even the metal extruder mounting plate. It allowed me to hang the extruder directly underneath the X axis rail. There's much more to say, but.... I'll let the pics do the rest of the talking. Thanks for viewing! And oh yeah, it prints SO nice too. I've added a couple pics of some RC airplane parts I'm printing from 3DLabPrint.com.