This is a bowden style extruder?? Nice work!!! 
Has anyone ever cut grooves right into the motor shaft? This method may give enough surface are to get enough grip… Just wondering
Yes, someone did this already. Can’t get the source but remember that the thing was still in good shape after more than 1 year…
@MakerGal Nice to see some neighbour here (I’m a frenchman living in Portugal more than 20 years now)!
To answer your question, yes, this is bowden and direct would make more sense as the filament is getting out on the very same side as it is loaded from. Maybe a future version can have the loop coming back at 90º instead of 180º, but that’s for later.
@Brook_Drumm I guess the concern with that is: When the shaft gets dull, you have to pitch the motor. You kinda want a field replaceable part for that as it’s a wear item.
@Brook_Drumm , the problem is that when you get the diameter too tight like that, it engages the filament less. I’m actually of the belief that people should be using larger diameter drive gears (with gear reduction), not smaller for this reason.
@ThantiK What you say make sense, but still here, we come with the benefit of having twice the area of contact. And good luck with getting the flint wheel dull: @Mauro_Manco has done some experiments and even a diamond drill lost some teeth!!! It’s grippy but not too deep to grind the filament. Anyway, the only way to be convinced is to try it…
@Nicolas_Arias 11 mm done. Could you give it a try? It took me a little longer since the substantial diameter change has influence on other geometry, and even with parametric design tool, it wasn’t an obvious task.
Let me know if you want it in other format or STL.
Here you go… If anyone else want to help “debugging” it, you’re welcome:
about to print! 
thanks
By the way, according to http://reprap.org/wiki/Drive-gear MK8 should be compatible directly (hobbed diameter ~7 mm as for the flint). There maybe be an issue with the "non-hobbed part colliding with the body of the extruder. Anyone can confirm?
wait what is this
@Michael_Memeteau , the mk7 need to be adjusted. The body collides with the mk7 non hobbed part, a little. after filing some plastic, when fully closed, filament doesnt grip on the hobbed part. I used a mini hyena, but its the same diameter as a mk7.
Ok. I’ll give it a check.
Okay…now that I’ve peeled out the flintwheel, I find it’s too big for the shaft…where are you guys finding mini-flint wheels?
BIC lighter mini
bic normal ~6mm hole coil
bic mini ~5mm hole coil *Work°
bic slim ~5mm hole coil *Work°
Clipper large <3mm hole SOLID
Clipper mini <3mm hole SOLID
You probably got yourself a “regular” bic.
We in QR community stay collect and try any lighter for find how lighter mount same solid flint wheels with 5mm hole https://plus.google.com/+ShaukiB/posts/NCsCKaiu349
soon want expand this strange request in some smokers circle… 