Now THIS is what I got into 3d printing for. A fully developed community created and iterated solution to a problem…a design that couldn’t_possibly exist without 3d printing. Now I just have to attach the flintwheel. Printed in PETG, which gives really good results when I cut the print speed to half my ABS speeds. #saintflint @shauki @Dale_Dunn @Mauro_Manco (So who is mmemetea?)
Mike, this are a final work of @Michael_Memeteau based from @shauki work/idea #doubleforce . #saintflint are a state of art out from QR community for simple #bicgear but usable with other gear too.
is there a step/solidworks of this extruder?, i would like to modify it so a mk8/7 can be used.
Sure Nicolas.
https://www.youmagine.com/designs/saintflint-extruder
Inside this link have onshape design need only modify Nut ( saintring 
) for mk8/7
dumb question what exactly does this improve?
@Mauro_Manco , im looking at the onshape design, but cannot get what should i modify (theres no “Nut” geometry. I guess that what i need to modify is the adjusting wheel (that can be called a nut :D) to make it a bit bigger, right?
@John_Car For a start:
- No slippage unless you go way past your step motor spec’s;
- Avoid local deterioration of the filament (if it does, normally the other side should help pull the filament out of the zone of trouble (if it doesn’t, probably thing are likely to get awry anyway for another reason);
- More stable and constant feedrate (no more under-extrusion):
- Easy loading for a bowden set-up (just remove the ring and load manually);
- Lost-cost solution;
- Low RPM, this where you get the most out of your step motor;
- No ventilation required;
- Works even with 0.4A step motor;
- Works with semi-flexible filament (support in pull and push direction);
- Open & original design;
Need more?
@John_Car , uses both sides of the drive gear to improve driving force on the filament. This means you can potentially use less idler force overall because there is more driving surface. This means less deformation of filament, and possibly better reliability.
@Nicolas_Arias I already did a modification to accommodate a 8.54 mm diameter flint. I was on my way to get a 11 mm ready but this mess up a little with the way Onshape is building the thing. Let me another 24h and I can surely come with something that should help you and others as well. OK? By the way MK7 or MK8?
ops sorry i called Nut because no remeber name of geomery 
but i hope @Michael_Memeteau ressponse soon your question but i think sure need only modifiy adjust wheel in case wait and print arms… and wait response meantime can use nylon string or rubber for close well your saint… as in this post from other user of qr community (inside comment ring for 8.45 dimeter drive ) https://plus.google.com/110174019370807515508/posts/CguLqoq3CzD hope this can help you.
Thank you for the explanation
I dont really have problems with gripping filament, but i see the potential for a long bowden tube or maybe when you start using something like a volcano that chews filament. But most apealing is filament doing a 360 so can feed from rolls suspended over the printer and have it exit above again to the bowden tube. Wonder if there is a direct extruder application for this.
Genius design. Basically you are getting twice the grip for the same power???
#saintflint is getting so much love! Great…
The original design is with the lighter part that grind the flint (hence the name). The small diameter and the material it’s made of are very interesting: no big groove on filament, yet this is a very hard material (remember, flint is a stone like in “Flinstones”). This make up for a very low cost and very durable solution.
@Michael_Memeteau i guess the most used hobbed wheel is the mk7 today, so, i would make mk7 first, mk8 after that one 
I’m on it…
@Griffin_Paquette … with the added benefit of balancing the forces on the step motor. Also, even if the flint/coil is not perfectly centered on the axle, the overall diameter is what matters, so no force fluctuation. No need for a spring as the numbered plastic ring will take the deformation as it’s not in whole contact with the conical thread.