First test with the tiny 50g NEMA 14 steppermotor
Someone has to ask the dumb questions, but what exactly am I looking at in that assembly? What is that motor doing, and what are the reasons/advantages, for the gearing you are using? It also seems the small size, at least in this application, is negated by the fact t hat you need gearing. Again, I don’t know, I just know the traditional i3 clone designs really.
less mass to move … also more precise filament transport.
I tested these (with 60/13 gearing) and found them to be too weak.
The only worked if run at a fairly high current, and then they burn out easily. If they could be made to work it would be awesome.
Seems to work http://fine.My extruder now weigh only 180g.
What current are you running them at?
it probably would be worth indicating what temperature and filament as well. I assume a hotter temp for a particular type of plastic would require less force.
First print in PLA 0.15mm layer with 0.2mm airbrush nozzle 205c. 0.15 are probably a little too much for 0.2 nozzle.@Oystein_Krog
I did not change current from the other stepper just felt with my fingers if they got too hot.
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I printed a lot with a 8.5 Ncm nema 17 pancake and 12:50 (as far as I can remember), which will be reactivated soon. So a 5 Ncm nema 14 should work imho. The only issue I found wasn’t extrusion torque but somewhat limited retraction speed. https://youtu.be/oceiGND5-3g
@Markus_Seidt : I’ve also tested the pancake stepper you use in that video and for me it works much better than this one. It is unfortunately also much much more expensive.
The limited retraction speed is caused by excessive gearing … The controller just couldnt keep up with the amount of steps per mm needed. A 13:60 reduced extruder tops out at 80 mm/s (with smoothieware)
I think the 1:3 approach most manufacturers use is more appropriate 
P.S. Hi Markus … I’m “thefrog” on the ultimaker forum
With my 1: 3 gearing, I get 12Ncm with these 4Ncm stepper`s which is enough with a properly designed extruder. It’s the retraction speed that can cause trouble. I’ve used stepper motor with 5Ncm in my extruder for almost a year without any problem.
What is the problem with retraction speed? Are you skipping steps whilst retracting or does the controller limit speed?
Don’t those big machined aluminum parts negate the mass savings of the stepper ?
With 148g I think it’s ok.
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