I designed and printed this after enabling LIN_ADVANCE in marlin. I was finding without the gearing my direct drive extruder that came with my hictop machine would sometimes skip and I would have to run the stepper very hot. With this, I can use a pancake size stepper and still never skip a beat running the motor fairly cool at the same time. I have been using this for awhile now and have noticed a marked improment in the overall smoothness of my prints and stability of the printer. This extruder can act as a bowden extruder. I have included a clip that the motor can snap into which then snaps onto the side of the z carriage of many kit printers. The extruder is threaded and ready to accept a standard 6mm pass through bowden coupling. I prefer a direct drive system myself, in which case, the stainless throat that comes with hictops and many other machines can be screwed directly into the same threaded hole. This provides a very direct route to the hot end great for flexible materials. Please see my other thing for mounting this extruder and the standard hot end parts in a direct drive setup.
18-03-26 - Replaced regular nuts with nylon lock nuts
18-04-14 - Uploaded changes related to revision 3. See PDF drawing revision 4 for details. Uploaded an STL of the complete assembly
18-08-25 - Uploaded revision 4 of extruder assembly and revision 3 of cover. See drawing revision 5 for details
18-10-29 - Packaged last revision that is backwards compatible with direct drive bracket. Added revision 7 files that have been changed to create a more compact assembly
18-12-19 - Revision 8.2 - MOVED CENTER AXIS OF FILAMENT HOLE CLOSER TO TANGENT WITH FILAMENT GEAR. REQUIRES LESS FORCE ON TENSIONING ARM TO ATTAIN GOOD GRIP ON FILAMENT. NO OTHER PARTS WILL NEED TO BE REPLACED. ADDED EXTRA INFO TO BOM
19-04-16 - REV-8.3 - REMOVED SMALL SPACER WASHERS. CHANGED OTHER PARTS TO INCORPORATE BOSSES TO ACT A BUILT IN WASHERS. UPLOADED A .STEP FILE ASSEMBLY
I printed all the parts in PET-G because I find it slides on itself very well. I am also able to lubricate the gears with an sae90 gear lube with no illeffects to the material. Keep in mind some parts will need supports. The gears and washers I printed at 10mm/s to ensure dimensional accuracy. It is very important on these parts to ensure meticulous extrusion calibration or the gears will run tight. If set perfectly the gears run very smooth with no percivible backlash. all parts were printed with a 0.2mm nozzle. I would not reccommend going bigger that 0.3mm for any of the parts. This is a very picky print. Everything needs to be calibrated perfectly. Your first layer height has to be spot on.