prusa i3 direct drive extruder for e3d hotend and mk8 drive gear

thingiverse

Here's a rewritten text of the original: Direct Drive Extruder for E3D V6 and MK8 Gear Fitting Directly on X Carriage Along with switching to an E3D hotend, I also wanted to upgrade to a direct drive extruder since none of the designs found on Thingiverse suited my needs perfectly. I'm transitioning from a JHead paired with Greg's extruder, so this is my take on a direct drive extruder meeting specific goals: 1. No bowden design 2. Extruder should not narrow build volume (old extruder limited z-height by motor hitting bracket) 3. Weight-balanced design to prevent 'falling forward' (limited by motor clearance) 4. Symmetrical design for easy fan mounting 5. Cable management (optional) 6. Flag for optical endstop (optional, shown here) 7. MK8 drive gear 8. Suitable for E3D v6 1.75mm, requiring a 4mm bore so PTFE tubing can extend into the extruder below the drive gear 9. Attachable to x carriage with 30mm hole distance 10. A little more rigid than other designs An optional fan duct fitting this design is available here. The extruder design was loosely inspired by Hackerbot's direct drive extruder. Instructions Mandatory printed parts: DDExtruder DDIdler MountingPlate HotEndBracket Required nuts and bolts: 1 x MK8 drive gear for 1.75mm filament 1 x MR105ZZ bearing (5x10x4) 1 x M4x50 screws 4 x M4x30 screws 5 x M4 nuts A spring for the idler Few M4 washers (optional, use to increase tension if necessary or try shorter screw) 1 x M3x16 screw 1 x M3x20 screw 1 x M3 nut 2 x M3 washers 3 x M3x10 screws E3D v6 and PTFE tubing, of course Optional: CableBracket: Replace 2 x M3x10 with 2 x M3x20 screws. Some zipties BearingExtender: 1 x MR105ZZ bearing Assembly instructions: Print everything at 0.2mm layer height (or 0.1mm, but that's excessive) to avoid issues with item heights. Remove support material MountPlate: Break pillars free from M4 nut shafts and remove flag for optical endstop (about 2mm) or break whole flag off if you don't need it. DDIdler: Remove supports so the idler can be clipped into place later. Put bearing onto the shaft, then add two M3 washers onto M3x16 screw and screw it into the shaft. Secure with M3 nut. The extra rigidity helps keep everything stable. DDExtruder: Place DDIdler into the extruder. Ensure smooth movement. Attach to motor using M3x20 screw while holding idler in place. Use 3 M3x10 screws for remaining screwholes. Insert Mk8 drive gear, line it up with filament bores. Do not assemble spring and screw until you want to add filament. MountingPlate: Put M4 nuts into holes and attach DDExtruder with 2 M4 screws. Install E3D hotend with PTFE liner and ensure required length for PTFE liner If using cable management bracket, print and secure with M3x20 screws instead of M3x10 screws. Tie cables to the brackets using zipties.