MMU2S Adapter for Bondtech BMG MK3S Extruder

thingiverse

This is a remix of the Bondtech Prusa MMU2S MK3S Adaptation by @Leonrsmln31. Credit goes all to him for the parts. I have changed nothing with the design, but am just making this design to have better instructions on what to print and how to put everything together! I found it very hard to figure out how everything gets put together and what needed to be printed. So I have simplified it. This contains all the parts you need to convert your Bondtech BMB MK3S extruder to use it with the MMU2(S), and no extra parts. **1: Print These Items:** • SensorcoverLatch • Sensortab • Topplate_M5x0.8_MK3S_MK2.5s • Drill_Template Print all files in your choice of PLA or PETG, 0.20mm layer height or lower, with standard print settings. **Optional Parts:** • Topplate_M10x1.5_MK3S_MK2.5S - instead of the M5 version if you wish to supply your own M10 pass-through bowden connector. If you want to use the one that comes with the MMU2S, print the M5 version up above. • Bondtech_Hinge_Tab - if you wish to print your own Bondtech Idler door with the tab permanently on it, instead of drilling your SLS Bondtech door to install the tab. I recommend drilling the black SLS Idler door instead because SLS is lighter. **2: Clean Up The Prints** The holes for screws in this design print smaller than needed. Use a drill bit to widen all the screw holes, and also widen the hole for the filament path a bit too. Use a razor to remove any elephant foot from the edges of the parts, and use a heat gun or hairdryer to remove any strings. **3: Assembly Instructions** 1. Using the drill template, drill a hole into your Bondtech SLS Idler door, and install the sensor tab into the hole. The sensor tab installs from the left side of the door, if you are looking at the door from the front of the printer. The sensor tab might print too large to fit into the hole, so just use a razor to make the diameter of it a bit thinner. But you want it to be tight in there so it doesn't fall out, so just carefully keep removing material from the sensor tab until you can get it to go into the hole snug. Tighten the idler door back onto the extruder with the thumb screw. 2. Screw your bowden coupler (M5 or M10) into the top plate. Then, screw your top plate onto the top of the extruder with the M3x10 screw. 3. Place the IR sensor into the SensorCoverLatch printed part. The pins for the wires should be facing out the back of the part. Use the tiny M2 screw (that comes with MMU2) to screw the IR sensor in so it's tight, but don't overtighten it! If you are having a hard time getting the screw into the hole, don't force it! Ream out the screw hole a bit more and try again. You should be able to get it in there. 4. Move the sensorcoverlatch and IR sensor all the way to the left on the groove, so that it's close to the bowden coupler, as far as it will go. Use an M3x40 screw through the back screw hole to screw the sensorcoverlatch part into the topplate. Add an M3 nut on the end of the screw, and tighten it just until the nut catches the screw. 5. Plug the IR sensor cable into the IR sensor. It has a latch on it and should clip onto the ridge. **4: IR Sensor Calibration** 1. Make sure no filament is loaded into the extruder. 2. Now you go into your printer settings to the support screen, and go to IR sensor info. It should be reading "0". 3. Start tightening the M3x40 screw on the sensorcover latch. As you tighten it slowly, the sensorcoverlatch should start moving to the right. Pay attention to the IR sensor number on the printer. 4. Once the IR sensor number changes to "1", you have gone too far. So loosen the screw just until it reads "0" again. Now you are all set and ready to print with the MMU2S! Follow the rest of Prusa's instructions.