Friday, January 22, 2010
Geared Nema 17 Extruder
I didn't have a lot of luck with the standard Mendel direct drive pinch wheel extruders, most likely because the steppers I had were not strong enough. I ordered in some 5 kg*cm Nema 17's, but unlike the datasheet, they had substantial flats on the shafts, which made building a direct drive extruder problematic. So, I thought I'd try building a geared extruder, using printed gears.
Green PLA is my new favorite color!
Also, I mentioned on the wiki that this was based on Adrian's geared Nema 14 extruder, but really it's a mashup of that and Nophead's great geared extruder designs, just tweaked to fit the hardware I had handy.
Right now I made the drive gear twice as thick as the driven, so I don't need to locate the gears on the shafts too accurately axially. Helical would make them quieter at the cost of some axial loading, but they're pretty quiet already.
Besides, I don't think Forrest has released his code yet, and the ones on Thingiverse are square, which do not mesh well when printed on my printer.
It would look cooler though. :)
miscellaneous/Art of Illusion Scripts/
It can make curved herringbone gears. If you want to play with it, try modeling a gear couple of roughly the same size as the one you just made. Once you have the number of teeth you want and so on, try changing the shovel segments from its default of 3 to something around fifty, to slowly generate a curved herringbone pattern.
But where could you find coloured PLA, it's possible to find different colours?
Enrique, I'll have to check out your script. I've been using Alibre instead of AOI, as Alibre works a lot better for someone with my CAD background. I do use Skeinforge for all my prints though; it's very valuable. Thanks!
Tombo, the green PLA was a sample from http://ultimachine.com/ , I imagine they'll have it in stock soon.
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