Extruder-X universal -1.75/3mm, direct drive extruder, Nema 17/23

by 3dmakers Nov 14, 2013
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Too bad it doesn't have any bowden support! :) This extruder is not mountable on a mendelmax frame for example.

you can use one of bowden adapters, like:
Bowden adapters:

(Greg's Accessible) Wade's Extruder Bowden Adapter
by summetj
Bowden Cable Coupling for RepRap
by Erik
Bowden pneufit convertion kit (JHead)
Printrbot Simple Bowden Conversion

It is why I have released nema23 version. Maybe someone will test it.

I tried to implement this with Nema 17 / 3mm filament, but... not enough torque. I burned out the E motor driver... must have turned up the voltage too high or something.

New version witn 45 degrees fan mount added

Does anyone know a source for an MK8 gear that will fit a NEMA 23 motor w/ a 1/4" (6.35m )shaft. The eBay one from Denmark has a 5 mm hole, but says the drive gear has an effective dia of 7 mm. I could drill it out, but I'd be concerned that the gear might be too thin?


I have made and tested a few variants of MK7 nema23 ready gears starting from 9mm til 20mm diameter. Gears are available in two variants: Hardened steel - 45HRC or brass. With nema23 and and large pulleys quality you dont have to choose between quality and torque. Some photos: http://thingiverse-production-new.s3.amazonaws.com/renders/2e/25/d9/c1/8c/WP_20150418_00_58_34_Pro_preview_tinycard.jpg

I have quite simple solution. Take flat file, nema23 motor on long cables, run motor at top speed and reduce diameter to 5mm. It took 30 minutes in my case :)

Just remember to put a piece of felt with a hole in it next to where you're filing, and tape it around the motor a bit. You don't want to risk getting ANY metal filings/dust into the stepper motor.

I like this one. Have you tried extruding 3mm filament with a nema17 motor? Do you think it will work, or is the torque too low?

I am even not going to test 3mm filament with Nema17 :).
My rationale is that: average max torque of nema17 motors if ~0.45Nm, even with small drive gear with 7mm diameter we would have max theoretical torqe ~13KG. From my experience with 3mm filament and geared extruders torque ~20KG is needed, so when we substract gear train inefficiencies,..., and friction ~10% (because of direct drive extruder has no such gearbox:) ) we will have ~18KG. So it is why I have designed Nema23 version, you can easly get 0.6Nm which is not so heavy ~ 0,6kg, which fullfill such requirement.


Thought so. I have some Nema17 motors that I don't use, so I thought about using them. I have too much 3mm filament to make the switch to 1.75mm (and a 3mm e3d head). I'll go with geared for now and get back when/if I switch to 1.75.

With some limitations like not so hi. layer (0.3), nozzle 0.4 bigger and slow speed ~40mm/s, you can be successful with 3mm.

If I try, I will get back with results.

Well, I am tempted to try it out, but I might want to start out with better gears for my current extruder and get everything to run smoothly first. It's an old Mendel that has been running fine, but the print is just not "nice" enough. I think it needs a recalibration.

I have some meters of 3mm like you :), and going to test intenively nema23 direct extruder. My latest prints http://printerzero.blogspot.com/2013/11/150-microns.htmlhttp://printerzero.blogspot.co... with 150 microns quality :) (geared extruder)