Does your MMU2.0 cutter work?
Does your MMU2.0 cutter work? I never seen my cutter cut any filament since day one and I am only seeing some stringing cut by the blade.
Re: Does your MMU2.0 cutter work?
amazingly it did cut once. i accidentally bumped one of the spools behind the machine and about 5mm popped out the front that i didn't notice and when the selector moved it actually cut the piece off and it fell into the catcher on the front of the MMU2.
the last time the blade hooked a piece of filament and it bent 90 degrees in front of the blade and jammed between the assembly body and the blade and i had to reset the MMU2
“One does not simply use a picture as signature on Prusa forumsâ€
Re: Does your MMU2.0 cutter work?
I wish that they implement in such a way that it cuts every filament change to remove deformed tips.
Re: Does your MMU2.0 cutter work?
my blade is out. it was a pain. really. should have been done better....
I have a Prusa,therefore I research.
Re: Does your MMU2.0 cutter work?
I wish that they implement in such a way that it cuts every filament change to remove deformed tips.
i don't understand github because i'm old and don't care; but maybe somebody opened up a firmware request where the filament hits the finda rolls back via the pulley, the selector moves, then the filament is jogged forward say 5-10mm and then the selector comes back and cuts before moving to the next tool change. that would at least give the knife a purpose. strings it has no effect on because the strings just bend under the knife.
obviously this knife feature as currently implemented is doing nothing
“One does not simply use a picture as signature on Prusa forumsâ€
Re: Does your MMU2.0 cutter work?
I had the same 90 degree bend and drag problem as well. It dragged the blade half out of the holder and i removed it manually. I don't think i will put it back in.
I did actually see it cut a piece of filament once because it shot out of the MMU2 and hit me on the forehead!
RE: Does your MMU2.0 cutter work?
The blade has come loose on mine. Does it make sense to fix it or should I just remove it?
RE: Does your MMU2.0 cutter work?
@ray-b2
Firmware version 3.90 enables the cutter and gives you a menu option to cut manually.
The MMU2 printed part has R2 parts for the selector and front PTFE tube holder which does a better job of holding the blade in place.
I have the new parts and upgraded to fw V3.90-RC3 and have the cutter working.
So your choices are:
- Take the blade out
- Print the new parts and upgrade to FW V3.90 (It is now at RC-3)
- Print one of the updated selector designs on Thingiverse and upgrade your firmware.
The cutter isn't an end all solution. You need to address stringing and bad tips by getting really good profiles for your filament and/or buying better quality filament.
RE: Does your MMU2.0 cutter work?
My filament cutter work, I've tested it first with the 3.9.0-rc1 fw, I just made a little change to the front PTFE holder.
RE: Does your MMU2.0 cutter work?
And if you have the "open canal" or magnet FINDA mod, here you go:
https://www.thingiverse.com/thing:4219114
RE: Does your MMU2.0 cutter work?
Now that fw 3.9.0 supports cutting i have been testing it a bit on my mk3s + mmu2s with the new blade holder.
If i from the menu choose to cut one of the filaments, the printer behaves ok until directly after it has cut the filament, the moment selector cuts it the mmu behaves as if it got reset.
Also i have tried both normal and stealth mode on mmu but didnt see any difference (i almost always have it set to "Normal" and not stealth)
Any idea why it keeps reseting it self when cutting?
I should also add that mmu reseting itself is not exactly a new thing, the difference now is that i can easily reproduce it by doing a cut.
I have contacted prusa support about my mmu issues (long before cutting was implemented and fw 3.9.0) but all i got was to check power and cables to mmu and that has been done multiple times and i really don't believe that is the issue (of course i'm not excluding power problems but not because of cabling)
RE: Does your MMU2.0 cutter work?
Does your MMU2.0 cutter work? I never seen my cutter cut any filament since day one and I am only seeing some stringing cut by the blade.
This may be naive, but I really have not as of yet figured out exactly what that blade does or is supposed to do.
RE: Does your MMU2.0 cutter work?
@jsw
Update to fw 3.9.0 and preferably also replace the 3 updated plastic parts, two for the blade holder and one for the ptfe holder that holds the 5 short ptfe tubes.
Then go to menu and select cut on one of the filaments.
RE: Does your MMU2.0 cutter work?
@jsw
Update to fw 3.9.0 and preferably also replace the 3 updated plastic parts, two for the blade holder and one for the ptfe holder that holds the 5 short ptfe tubes.
Then go to menu and select cut on one of the filaments.
What did they change in the PTFE holder? I haven't been following. Almost everyone I know that has a MMU has already done this mod (basically a must): https://www.thingiverse.com/thing:3233579
RE: Does your MMU2.0 cutter work?
@nimaim
That's not the ptfe tubes i'm talking about, it is the other one, the 5 short ones close to the cutter.
The shape of that piece is changed a bit, probably to avoid bending the very end of the filament as it is cut, old one have the slot where the blade moves in more like a V shape, but new one is a bot more flat and supports the filament a bit more.
Also not sure why this modified part was not mentioned in the patch notes
RE: Does your MMU2.0 cutter work?
@nimaim
That's not the ptfe tubes i'm talking about, it is the other one, the 5 short ones close to the cutter.
The shape of that piece is changed a bit, probably to avoid bending the very end of the filament as it is cut, old one have the slot where the blade moves in more like a V shape, but new one is a bot more flat and supports the filament a bit more.Also not sure why this modified part was not mentioned in the patch notes
OH! Interesting, thanks. I sanded down each filament path on that holder a good amount so I'm good there, but yes I agree it definitely needed improvement. The biggest issue is if there is even the slightest friction, filament won't be able to get pulled by the motor because that piece previously had no wiggle room.
RE: Does your MMU2.0 cutter work?
@nimaim
not sure what you mean because each of the 5 holes got a short ptfe tube that is chamferd in one end and i dont understand where you could possibly sand.
the tricky part is to turn the chamferd side the right way so filament dont get stuck on its way out towards the extruder (completely flat filament tip, like after it is cut)
RE: Does your MMU2.0 cutter work?
I have not been following MMU news for a long while. I have removed the blade long ago. (as it came out loose)
Can anyone kind enough to tell me exactly which parts have to be printed and replaced? (I've downloaded the stls. Please point to me which file to print. Thanks in advance. )
One more question: is the cut filament routine added to the MMU printing process? Under what circumstance do I need to use this cut filament function shown in the menu?
RE: Does your MMU2.0 cutter work?
The changed parts is listed in the patch notes for fw 3.9.0 except for one.
The parts are: mmu2-blade-holder, mmu2-front-PTFE-holder and mmu2-selector-finda.
Pocket for blade is deeper now and the cover that goes over it is modified so it is easier to get it to stick and align when screwing in the two screws holding it in place.
There is a menu entry to cut a filament "manually", you just pick which one you want to cut then the mmu2 does its thing, hopefully without bending the filament.
Note that the tip will be completely flat and not pointy, so probably good to make sure the short ptfe tubes got the chamfer at the correct side.
There is also a menu entry to turn cutter on and off, haven't tried it yet but i would guess this one makes a cut between each filament swap while printing.
RE: Does your MMU2.0 cutter work?
Yes. It works reasonably well. It took quite a bit to get it set up properly though. The indentions are not quite right in there. I did break my blade on some carbon fiber Poly-carbonate filament, it goes through flexible filament like butter though.
As has been said above, it would be nice if it made a sweeping cut periodically to kill all the stringers.