Small Nema17 for extruder/feeder?

Hello,

I'm still continuing to plan my new printer. It will be an Ultimaker-style 3d printer with a bit larger print volume.

I want to use three different extruders, all of them build as bowden feeders. My question to guys is: Do I really have to rely on those standard Nema 17 motors or can I also use smaller versions of them, like this one that has a holding torque of only 36Ncm? Would that be enough for bowden feeders?

It depends on the extruder design. If you will be using a 1.75mm direct drive extruder then I recommend you use a motor with more torque. OTOH if you use a 1.75mm extruder with 3:1 or 5:1 gearing, you can use a shorter, lighter, less powerful motor. The motors I use with my 3:1 geared extruders have about 25Ncm of torque at rated current, very similar to this one [www.omc-stepperonline.com]..

I don't think there is any advantage to using a 0.9deg/step motor for the extruder over the more usual 1.8deg/step. If you use a geared extruder, I suggest you use 1.8deg/step to avoid getting a very large steps/mm, which could limit the speed at which you can load and retract filament.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Please, could you tell me more about your 3:1 geared motors? Did you print your gear drive yourself?

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RichterK
Please, could you tell me more about your 3:1 geared motors? Did you print your gear drive yourself?

Yes I printed the gear drive myself. The various parts can be found at [www.thingiverse.com] and [www.thingiverse.com]. It's a variation on the extruder for the RepRapPro Ormerod, see [reprappro.com].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].