Here I have some feedback about the dual motor extruder with two belts as drive.
Already after the first usage the belts looked very used, and I had to worry that they would wear out quickly. But now I used about 20 Kg of filament, and they still look like they did after the first print and they still have good grip.
Even the results of the prints has been better, the slip is much lower, the motors will lose steps before it allows high amount of slip. This is mainly an advantage but also can be a disadvantage if settings like bed leveling are not precisely set. Printing on high speeds works generally better.
Unfortunately I can’t prove it, but my 3D prints seem to have a nicer surface, I suspect that this is due, among other things, to the fact that there are fewer air pockets because the filament does not have any notches caused by extruder gears.
The maintenance procedure when the filament is empty is also a bit annoying. My filament sensor only notices that the filament is finished when the belt is no longer touching the filament. This is because my filament runout sensor is at the end of the bowden tube very close to the hotend. That’s why it’s necessary to loosen 2 screws to remove the rest of the filament. But ok, that can be done in 1 minute.
Other people would typically not have this problem as the runout sensor will be located at the other end of the bowden tube (before the extruder).
Overall, I’m very pleased because the benefits far outweigh the benefits for me, it’s one of the best upgrades I’ve ever made.
If I ever build a second version I would probably install a dial that allows the filament to be moved/inserted by hand. The rest is fine
Edit July 2024:
Some words about durability: The printer now Printed 40 KG Filament with max pressure (Max Speed) means max load on the belts.
I think I should have increased the pressure on the belt when printed 35 kg. It still works but I have more slip.
Re-tensioning helped this time, I think at 70 kg I will have to replace the belts.
The result is at least ok I think, as 70 kg is more than most printers prints in it lifetime…