Gavtech™ Dual Drive Bowden Extruder v1.1

thingiverse

Update 28/05/18: I've added v2 body, featuring an adjustable spring tensioner, improved filament path and rear of the body, and a "DD" logo representing Dual Drive. The V2 stepper gear has also been included for printing from TPU. I successfully tested it with 100% concentric infill using 98A Surreal TPU, which works very well and allows more pressure on the filament from the extruder gears. Additional pictures have been added to show how to assemble the parts. Update 26/05/18: An 18t gear set has been added, with thicker teeth than the original gears, allowing for closer positioning of the extruder gears. Please consider donating via PayPal on my website http://ferociousdesigns.co.uk or through Thingiverse's tip function. All donations are greatly appreciated and encourage me to design more items! Here is my dual drive extruder design, inspired by Bondtech. I printed the entire thing in 25% cubic infill with a 0.2mm layer height and parts oriented as saved in the STL files. PLA was used, but you can use whatever material you prefer; Nylon might be best for the gears at least. Use supports only touching the build plate for the main body and also suggest support interface / roof. Supports should be placed everywhere on the arm with a support interface / roof to achieve the best finish. The "Arm Gear" is designed to push onto the smooth end of a brass extruder gear (like the Anet A8's stock gear). You may need to remove the grub screw to get it in, and at this point, you can either use a longer grub screw if available or glue the extruder gear into the recess in the "Arm Gear" part. The "Drive gear shim" is required to fit inside the extruder gear, as it has a 5mm bore, while you'll be using an M3 bolt. The "Stepper Gear" should be quite difficult to push onto the stepper shaft. This is intentional so that it doesn't move once installed; with some encouragement, it will go on. You may want to use a 10mm long 5mm wide aluminum standoff instead of the 3mm to 5mm spacer. I used: 1x M3x30mm pan head bolt for the gear axle on the arm with a nylock nut backwards. A 35mm bolt would be better here, but I don't have any. 2x M3x20mm Cap head bolts to go through the left side of the body into the stepper mount and finally into the stepper. This may vary depending on your stepper mount. 1x M3x40mm Cap head bolt for the arm hinge (I'm actually using some M3 rod I cut to length at the moment). 2x M3 Washers + 2x M3 Nuts for the arm shaft to hold the top extruder gear in place. 4x F623zz bearings in the arm (Anet A8 belt idler bearings) - https://amzn.to/2LvNS75 2x Brass extruder gears like the ones that come with the Anet A8 - https://amzn.to/2GNmgGQ or https://amzn.to/2IJIpeZ 2x PC4M6 Couplings. These will take some work to screw into the body; use a spanner or something... - https://amzn.to/2seeT5V As of v1.1, you no longer need the M3 washer behind the arm! Regarding the spring: I've found that using the stock Anet A8 extruder spring works best for me. Other springs with thicker wire are too stiff and cause jamming of the gears.