Inspired by Angus video “Reverse Engineering the 101Hero 3D Printer” I did some experimental design with the 28BYJ-48 to see how they might be used for an extruder. As already said its experimental and even as I have used two of the 28BYJ-48, they might even not be strong enough. But its fun to try. Lets see how it will end up.
http://www.thingiverse.com/thing:1597741
What weight? It would need an extreme makeover for slimming down the overall package. But a very cool experiment.
The complete package is 163 grams (2 stepper motors, all screws, nuts… even wires attached). A Nema in comparisan has alone 285 grams.
Cool! Tiko is suposed to use those motors too. Please let us know if it does actually work.
Well I have a working prototype, but not yet a valid testenvironment. I just attached it to one one of my existing printers but did not want to mess there configuration to much up (especially the current of the stepper drivers). So I just had a small time windows for testing to prevent the steppers from overheating. Not enough to get an hotend heated up. However the torque of the two steppers was surprisingly strong. I was not able to hold the filament with my fingers. Also: the setup of two extruder gears is amazing there is no slipping.
@Antonio_beta I also backed the Tiko and still waiting
I tink that backlash is the mayor problem with those motors, so the extruder doesn´t be much problematic (as you have seen torque is good) but the axis… I think they would be problematic to maneage, or maybe not!, who knows I havent try them but I would like.
@Nathan_Walkner thats right, but on the other hand they are easy to get and low cost. So replacement is not a big issue, but backlash is more serious.
@Nathan_Walkner nothing lasts forever and there is a niche for everything 
…but of course: If I want to have a reliable “working horse” I would exactly evaluate the way you do
@Tinkering_On_Steroid interesting as always, Are you FIXING another Kickstarter? this is becoming a trend
@_KaT_KaTZWorld . 
…no, that would be the third one. But I backed the 101 Hero just out of curiosity, not due to high expectations.
Awesome! I have been wanting to design a small extruder using these motors. The Micro 3D printer uses one of these motors as well, but they used one with a much larger gear box than the one that comes with them normally. I am assuming they had it custom made. It can push 1.75 mm pla at 40mm/s at 215c, so I know it’s possible. Let me know how your design works out!