Printrbot Metal Plus MMU (Prusa Inspired)

thingiverse

This is my Multi Material Upgrade (MMU) for the Printrbot Metal Plus inspired by the Prusa MMU. This collection of models has parts that I have remixed from: Josef Prusa's MMU served as a base to inspire mine. https://www.prusaprinters.org/ SpannerHands' MP spool holder was used to design the extruder mount, and his ideas influenced my modification. (https://www.thingiverse.com/SpannerHands/about) Walter's printable housing for Printrbot extruder gears was also remixed into my design. (https://www.thingiverse.com/walter/about) Please check out these talented makers. PLEASE NOTE: This modification limits the Z axis to 220mm from the standard 254mm, which wasn't a concern for me since I never utilized the full limit. I designed this upgrade to fit MY modified Printrbot Metal Plus, which already features SpannerHand's mods. This involved cutting the X cart and relocating the Z sensor using a blower fan for part cooling. If you decide to perform these modifications, you can either use them in conjunction with SpannerHand's changes or opt out of his mods entirely. However, if you choose not to modify your X cart, the part cooling fan might not align properly. I've also included designs for an E3D v6 and UBIS hot end mount; these will require modifications to fit the MMU. UPDATE - 08/04/2018: I have since removed this mod from my Metal Plus due to issues with printed extruders. I opted to order new bearings from Aliexpress instead of using the ones included in the Printrbot gear head extruder gear set. UPDATE - 07/27/2018: The extruders themselves are largely unmodified apart from enlarging holes for brass inserts, which were made as a mirrored pair and mount on the extruder mount with M3 bolts into M3 inserts. The mount utilizes Spannerhands' concept of attaching to the metal frame of the plus, with added cable tie holes for secure placement. To ensure that one filament is clear of the filament guide before another is inserted, I used clear PTFE tube, which also helps spot any potential issues and allows for quick action to prevent damage. They look pretty cool too! Electronics: I'm using an Arduino Mega & RAMPS 1.4 board as my main controller, which only supports two extruders. To accommodate the additional extruders, I've added Printrbot's Extrudrboard connected to the AUX-2 pins on the RAMPS and configured the firmware to utilize those pins. Parts list: - Prometheus V2 Hot End - https://www.distechautomation.com/products/prometheus-v2 - Brass inserts M3 & M6 - https://www.ebay.co.uk/itm/M3-M4-M5-M6-Threaded-Solid-Brass-Press-in-Barbed-Inserts-for-plastic/262993790868?var=562002386626&hash=item3d3ba6c794:m:mOHTFRbrYIVeJt2c76sT51w - M6 pneumatic fittings - https://www.aliexpress.com/item/10Pcs-PC4-M6-Pneumatic-Straight-Fitting-Connector-for-4mm-OD-Tubing-M6-6mm-Reprap-For-3D/32668216080.html?spm=a2g0s.9042311.0.0.3a8KMo - Extruder gear set - https://printrbot.com/shop/gear-head-extruder-gear-set/ - Gear set bearings - https://www.aliexpress.com/item/10pcs-Lot-MR85ZZ-Double-shielded-Miniature-Ball-Bearings-5x8x2-5mm-for-3D-Printer-Model-Making-Deep/32812874077.html?spm=a2g0s.9042311.0.0.3a8KMo - Clear PTFE - https://www.aliexpress.com/item/3D-printers-1M-2-4mm-Clear-PFA-PTFE-Tube-Teflon-PiPe-J-head-hotend-RepRap-Rostock/32611337704.html?spm=a2g0s.9042311.0.0.3a8KMo - Printrbot Extrudrboard - Currently Unavailable