Pancake stepper for flying extruder

[Falkia]

Thinking of saving some weights on the extruder for my Delta printer. I have a Micro Swiss Bowden Dual Gear Extruder M2714. Is there any suitable pancake stepper that will work? Running Duet2 Wifi with 24v PS.
Thanks
Fredrik

[oliof]

Since that's a direct/ungeared dual drive, I'd worry about pancake steppers bprovidug enough torque. I'd go for at least 20Ncm torque, so something like https://www.omc-stepperonline.com/nema-17-stepper-motor/nema-17-bipolar-1-8deg-22ncm-31oz-in-1-33a-2-8v-42x42x34mm-4-wires.html -- no idea whether that gets you any weight savings. Alternately, you could switch to one of the mini extruders with the round NEMA14 motors, but those are in the 45-80$ range ...

[Falkia]

@oliof thanks, that's looks like a good choice. I have some Wantai 42byghm810 laying around but they are heavy (340g).

[lord binky]

@falkia I have tried E3D's slimline motor (mt-1701hsm140ae) and compact but powerful motor (mt-1703hsm168RE) on my BMG in a flying extruder. I definitely hit limitations and have to compensate with flow rate with the slimline as I increase print speeds. When I'm doing flexible filaments it's not an issue since the print speed needs to be lower anyways. The other part is that the motor runs hotter than you'd expect and may run into issues there such as using PLA for your flying extruder mount. It is within spec and not necessarily bad but definitely outside of the comfort zone of many because it's smaller and you don't have extra torque to trade off in lowering your motor current to reduce the motor heat to keep it cooler than the hotbed.