The manual gives suggestions that have been successful, you are free to try any combinations you like.
ABS is probably ideal, the reason I did not use it is because it really lets off strong fumes during printing.
The idea with the TPU wheel is the smaller gear is softer and more forgiving with some flex. If damage were to occur it should happen to the smaller gear. So far other than polishing of the teeth the PETG/TPU mating has shown no significant wear in the dirt and grime of an open station tractor.
PETG and ABS are likely equally suitable for the hard parts of the project.
Thanks @PotatoFarmer for providing the files for printing these off.
The big gear i printed with PETG at .15 layer height and i think it looks absolutely perfect. The small gear is TPU 95A. i can’t wait to get these installed and test them out.
The type of TPU I used did not declare hardness. But the results were a very hard rubber like a hockey puck.
The finger guard is TPU so it can flex without cutting your fingers if a person is very determined to touch the pinch point. Also since it attaches without fasteners it flexes over the holder to stay on.
Plus TPU is usually pretty glossy so its nice against the more matte pteg.
here it not terrible as it is mostly in the support material. I am using the carbon fiber from filaments.ca. Just wondering what your nozzle temp is and your retraction settings. I know every printer is different but maybe just to give me an idea of where to start.
Anyone try and printing one with nylon filament? I haven’t tried printing any gears with nylon but I have found it to be a very impressive material that would probably be ideal for printing the gears as it seems to be very low friction and quite durable. The only problem is that it costs a fair bit more than PETG.
What kind of issue are you seeing? What kind of extruder?
I’ve been reasonably successful with a bowden tube extruder modified slightly. The trick is you have to go slow (30-40 mm/s). I’ve also seen it recommended to turn retraction off, but I have accidentally been printing with a retraction length of 5.5mm and it was working not too badly most of the time.