Why should I use a geared extruder?

Currently I'm using a NEMA 17 stepper motor from folger tech to drive my filament and has no gearing. It seems alright but lately I've been wondering if it's the week point in my 3D printer. For instance, I tried to use a .3mm nozzle and it was like riding the struggle bus given how slow I had to print with it.

Is it really worth it to use a geared extruder such as the wade extruder used by TAZ Lulzbot? Could a Bowden setup benefit from this?

Assuming you are using 1.75mm filament, to get enough force to extrude reliably at high print speeds, you need one of the following:

- A non geared extruder with a high torque (about 60Ncm) motor, run close to its maximum current;

- Or a much smaller motor (20Ncm torque is sufficient) with gearing between 3:1 and 5:1.

So the advantage of gearing is that you can get reliable extrusion with a shorter, lighter and cheaper motor. I use geared extruders in both my printers.

Edited 1 time(s). Last edit at 03/30/2016 04:02PM by dc42.

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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].

My BulldogXL, with its 5:1 gearbox, has been absolutely reliable in the 16 months that it has been on my printer. I don't try to print at 200 mm/s with it...

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]