MCG bowden extruder Feeder feat. ATOMIC extruder knob

thingiverse

PLEASE READ! Work in progress. After finding a printable feeder and using it under enclosure, I designed this. ABS printing requires 100-105C bed temperature, but after about 1h of printing, the enclosure temp rose up to a steady 42C. The feeder I printed was PLA, which bowed under spring pressure. Determined to reach my goal of getting rid of under-extrusion on my bowden Ender 3 printer, I made this. It's printed in PLA with 0.2mm layer and 100% infill. Top and bottom parts should be printed flat side down. The latch should be printed flat with supports and a "howling wolf" logo upright (it will then be on the side of your print, bolt hole aligned with Z-axis). It requires some post-print cleaning but not much. Make sure all holes are clear; if not, use a 3mm drill on the body and 4mm on the latch. After printing: * Use an M3 20mm (20mm including head) bolt and hex nut to bind top and bottom together using a hole near the bowden coupler. Tighten while making sure top and bottom are nicely aligned. * Slide the assembly in between the latch arms, ensuring the hex hole on the latch is towards the NEMA motor and the top/bottom assembly is 3mm (not 6mm) corner holes towards the NEMA motor. * The latch should slide freely; if not, check your print. * Use the stock Ender 3 feeder idler spring between the latch and the body. * Use the stock Ender 3 idler bearing with the latch. Use an M4 20mm bolt (including head) and a hex nut to hold the bearing between the latch arms. Press the assembly against a worktop, then place the bearing between the latch arms while trying to push the screw through. Put the nut in the hex hole and turn the bolt to keep it together. * Congratulations! It's assembled. Now use M3 25mm screws to bolt it to the NEMA motor. When everything is tightened up, it's time to screw in a bowden coupler. I recommend buying an upgrade for that as it allows the PTFE tube to reach the bottom of the coupler and improve filament flow. It's best to use a flat 6mm key and your thumb to gently screw the coupler in while holding it perpendicular to the side of the feeder, lining it up with the hole axis (doable). NOTES: The filament guiding tube formed by two pieces of the body pressed together might be too tight due to print settings. Before latch assembly, it's advised to drill through with a 2-2.5mm drill to open the tube and smooth out any inconsistencies to make the filament flow as uninterrupted as possible. Because I tried to make the filament bend slightly around the motor cog, the filament goes off the straight line between inlet and outlet sides of the guiding tube due to tangency of contact between filament and the mentioned cog. It's advised to cut the filament at an angle so that the sharp end hits the edge of the outlet part of the guiding tube. Please be honest in your comments. Let's make it work! I'm happy to answer any questions.