Steel substitute for brass extruder drive gear?
I love my new Original Prusa i3 MK2. I'm not sure if I've let it get cool for more than 7 hours since it arrived about a month ago. I've printed a wide variety of plastics, mostly PLA, PETG, and ASA (not an ABS fan).
I've also tried ColorFabb XT CF-20, the 20% carbon fiber filled copoly blend. I knew from reading that it was abrasive and I'd need a steel nozzle, that was no problem. What I didn't hear or read anywhere was that it will also affect your drive gear...
That's my poor hob nut with the rut down the center and the teeth all filed down flat.
I'm not complaining, the machine is engineered well, I assembled it correctly and it works fabulously. The XT CF-20 is good strong stuff, once you get it dialed in, it's easy to print, and looks *great*. I'm pretty sure that there isn't anything wrong with my retraction settings, it's just that a quarter kilo of carbon fiber will rub the nubs off your noodle grinder, uh, so to speak.
I don't think a lot of people have had trouble with this gear, and I'm having trouble sourcing a replacement that seems to work well. The inexpensive steel nuts available (e-Bay-mazon, drop shipped from China) are not particularly good, although they do seem to work.
Is there a better source for a replacement extruder drive (hob) gear? Thanks for your recommendations!
-Roger in Michigan
Re: Steel substitute for brass extruder drive gear?
Did you ever find a solution? I am currently looking for a new extruder gear as well.
Re: Steel substitute for brass extruder drive gear?
Prusa can now supply steel hobbed drive wheels.
ask on chat!
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Steel substitute for brass extruder drive gear?
Where is the chat? I can't find anywhere to talk with them directly from the Prusa website... maybe I'm missing it somehow, but the Contact Us page only has a form to send an email to them.
Re: Steel substitute for brass extruder drive gear?
Go to the shop, sometimes it takes a second to load the DHTML but a little orange tab with a huge arrow shows up on the lower right of the webpage. I think that is what she meant by Chat.
P.S. just talked to Shop Chat and they said they don't carry it in their e-store.
Maybe here https://www.filastruder.com/products/hobb-goblin-5mm-id-drive-gear
MK2S kit owner since 8/15/2017
Re: Steel substitute for brass extruder drive gear?
Guys,
please use our English section of the forums, you will definitely address more users there 😉
Thread moved
/ Knowledge Base
The guy behind Prusa assembly manuals...
Re: Steel substitute for brass extruder drive gear?
After chewing through the original brass hobbed gear with some carbon fiber PLA, I replaced it with one of these hardened steel mk8 gears.
It's a bit larger diameter in the low part, so it will require tuning your extruder steps per mm. It can also sometimes cause some problems loading the filament, since the lower hole isn't *quite* in the right place for the larger gear - but I only had a couple of minor loading failures at first, which were quickly resolved by slightly bending the tip of the filament inward before trying to load. After a few times, the filament stopped catching on the lip there and I haven't had any loading problems since. I assume it eventually pushed/deformed the top of the PTFE tube out of the way.
The only other issue I had was that it was rubbing on the lower ABS plastic that sticks up, with the opening for the ptfe tube, and it would make an awful squeaking noise when doing lots of quick retractions. I just used a little hobby knife to trim away a bit of the plastic on the back corner there and that fixed that right up.
Re: Steel substitute for brass extruder drive gear?
current prusa drive gear is all metal .
i talked to the support yesterday , and the picture was updated to the new one .
too bad the shipping is still way too expensive , so i'm looking for alternatives