Simple Direct Drive for Ender 3 and Voxelab Aquila

thingiverse

After I dug around trying various direct drive extruders for my Voxelab Aquila, many were horrible to print, and none of them quite had everything I wanted, so I designed this one. Design goals: 1. Be easy to print, with minimal supports and minimal post print cleanup 2. Be quick and easy to assemble 3. Make the distance to the hot end as short as possible 4. Don't sacrifice print volume 5. Secure the extruder to the carriage rigidly 6. Remain compatible with the stock cooling assembly 7. Be cross compatible between Ender 3 and Voxelab Aquila 8. Integrate some ease of use features for loading and unloading filament 9. Integrate some form of cable management Additional hardware for direct drive bracket: 2x 30mm M3 flat head cap screws 1x M5 nut OR 1x M5 T-nut This direct drive extruder bracket is secured to the carriage via one of the M5 roller bearing screws and a M5 8mm span nut (or a M5 T-nut) that is press fit into the part. I opted to ditch the little round spacer in order to add rigidity by using a well placed nut in its place. As M5 nuts aren't standardized in thickness, I have included a few STLs of this that can accommodate various thicknesses of M5 nuts in order to maintain the correct spacing of the roller bearing and the carriage. You should measure your M5 hex nut that you intend to use before printing this part, in order to print the correct STL for it. I also threw in a STL that lets you use a M5 T-nut instead of a hex nut because odds are you have one of those lying around. Should you use the T-nut, it should be inserted into the part smooth side inwards. DO NOT use the washer with the M5 screw that secures the bracket. There is not enough clearance. Print the direct drive extruder bracket in its default orientation, with supports touching the buildplate at 80 degree overhangs. There is one small section that requires support. Elephant's foot is bad for this print, or else you will need to bust out the file to get the motor to fit on the bracket. In CURA, the setting "initial layer horizontal expansion" can significantly help mitigate elephant's foot. I prefer to err on the side of less elephant's foot, as under-sizing the first layer more than necessary has little negative effect on my prints typically. I set my initial layer horizontal expansion to -0.3. I printed mine at 100% infill, because I wanted mine to be rock solid, and it is. And if it isn't clear yet, you will have to separate your extruder's cable from the Z axis cable to use this, and you may want to extend it by 60mm or so, but you don't have to. More assembly instructions in Post-Printing. This is not required for the direct drive bracket, but I threw in a few idler arm STLs in various configurations, and they are named such that they can be identified easily. In more detail I will describe them below. The idler arms require additional hardware as well: 1x 10mm M4 screw for the bearing 1x 16mm or longer M4 screw for the spring tensioner 1. Standard bare bones, just a hole for the filament 2. Press fit for a bowden tube that bottoms out, that can be used as a filament guide. 3. Pass through for a press fit bowden tube, such that the tube can be cut to mate with the idler and hobb as close as possible. 4. Accepts a M6 bowden fitting for a reverse bowden setup. This is my preferred. 5. Accepts a M6 bowden fitting as well as a press fit bowden tube underneath, to cut down and mate with the idler and hobb. A small drop of superglue usually keeps tubes in place for me, if I need it to. Print your idler arm in the default orientation, while generating support everywhere with 80 degree overhangs. You will have to remove supports in the bearing cavity and file a bit. I use a pair of pliers to crush the support in the bearing cavity and wiggle it out. It isn't too bad. I'm going to assume you can put together the idler arm, so I won't put that in the post printing, as it is already fairly long. I went through many revisions until I was happy with this, so hopefully it works out well for more people than just me! If you enjoyed this print let me know!