MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Hey all,
So after upgrading and installing the MK3S + MMU2S units for my printer, I've hit a wall. I've gone through all of the pre-flight calibrations without any issues or errors, up to the first layer test.
At this point I could not get the filament to load to the nozzle, the MMU2S unit would grab it and push it through but it would reach (or almost reach) the primary extruder...only to be pulled back out by the MMU2S unit. Reading up on it it said that I should check to make sure the IR sensor was setup properly. After some tweaking I was able to consistently get the sensor to trigger a "1" when pushing the Allen key in. (*with the help of a wedge, until I can print a new extruder-idler-MMU2S piece) I've also checked the alignment of the gears and played with the tension of the screws associated with it. For whatever reason I cannot get it to print anything on it's own, with some pressure I could push a bit more of the filament into the line and it successfully "changed filaments" but backtracked immediately afterwards.
There is also an issue with the MMU2S unit is making a clicking sound (also squeak?) when I first turn on / load up the printer and when its starts loading the filament. I've loosened the two screws on the inside with no success and I'm honestly not sure if that is a normal part of the MMU or not.
Anyone out there have any ideas on what I should do next? I've shared a video of the clicking sound i'm getting. (I know the filament placement is awkward, but that is only a temporary setup until I can get it working) https://photos.app.goo.gl/PaLK1S9HGmtpqW4y8
Thanks
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
the mmu2 idler homes on power up , so you will hear the clicks as it hits it's stops
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Hey David, it seems to make that sound as soon as I turn on the printer, before anything seems to move or return to a "home" position. Is that different then what you were saying?
Thanks!
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
nope , as soon as the printer gets power as part of the MMU boot up the idler motor homes to it's stops. the selector and bondtech motors do nothing till the printer asks the MMU to do something. then the selector homes ( to both ends) if there is no filament detected in the FINDA
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Even when the 'Allen key' test gives you a solid 1 the printer can still fail to load with an IR sensor issue. Have you watched the IR sensor values on the LCD screen as the filament loads? See if it doesn't bounce around between 0 and 1 then. I ended up replacing the extruder idler door rather than shave a few mm off the IR flag.
Also, I found out recently that the state of the tips can make a huge difference too. If you had an MK3 and upgraded to an MK3S, you want to make sure you swapped out your extruder ptfe tube for the smaller internal diameter one that should come with the MK3S kit or MMU2S kit.
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Here are two more videos of what I'm experiences, although they don't really help that much honestly. I think I have a gear messed up somewhere along the line for the MMU2s to make that clicking sound upon startup. In concerns to watching the IR sensor values while attempting to load filament, I tired once but it seemed to cancel the load for me? I'll try it again there now and see how it goes. I'll double check the ptfe tube that I used as well. Thanks !!
https://photos.app.goo.gl/bnfko45mckyS1fCCA
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
The screeching sounds like metal on metal contact. Are your MMU selector smooth rods out of parallel alignment? The bottom one looks like it could be slightly lower on the 5th filament side, but it could just be the angle in the video. The thought is it could be that they are screeching when moving against the metal tube inserts.
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Do not use V6 Titanium Heat Break with MMU2S, hole is too small and will be jamming filament change all the time.
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Hi Alton, Have you found a solution to this problem? I have exactly the same behaviour, and the load to extruder fails 100% of the time.
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Dear All,
I have the same problem. The filament is not grabbed by the extruder gears. The IR sensor works differently with the MMU2S. With the normal MK3S triggering the IR sensor will lead to the gears to turn and to pull in the filament. With the MMU2S the gears always turns and after the filament is pulled in the IR will trigger the stop of the gears.
When I disconnect the MMU2 power supply, unscrew the tube and feed the filament in by hand (mimicking the standard MK3S) the filament is pulled in when I trigger the IR sensor by hand and all works well.
It seems that forwarding filament with the MMU2S until it is grabbed by the gear is a problem.
I played with all the settings but cannot get this working.
Any advice from Prusa?
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Dear All,
I have the same problem. The filament is not grabbed by the extruder gears. The IR sensor works differently with the MMU2S. With the normal MK3S triggering the IR sensor will lead to the gears to turn and to pull in the filament. With the MMU2S the gears always turns and after the filament is pulled in the IR will trigger the stop of the gears.
When I disconnect the MMU2 power supply, unscrew the tube and feed the filament in by hand (mimicking the standard MK3S) the filament is pulled in when I trigger the IR sensor by hand and all works well.
It seems that forwarding filament with the MMU2S until it is grabbed by the gear is a problem.
I played with all the settings but cannot get this working.
Any advice from Prusa?
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
My problem is that the pulley motor is turning to wrong way. It is not pulling in the filament to the extruder head but just the opposite.I confess I am an absolute novice but I did successfully build the i3 MK 3 from the kit and it worked perfectly. The upgrade to MMU2S has been less successful. Have a made a really basic mistake somewhere?
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
Following, because we are having the same problem. Down, Up, Down, Up, Down.... Goes to the extruder, but it doesn't even get to the Bondtech gear to pull it through.
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
I was going thruòugh this for about two months, I think that it's fixed now. The idler was warped and really did some strange things. The idler motor as it spun wobbled a bit pushing and pulling on the chassis. I printed a new idler and now all is great.
Phil
Stay safe and healthy, Phil
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
@pcweber Thank-you for your help. My attempts at upgrading to MMU2 has been a disaster from start to finish.
RE: MK3 to MK3S + MMU2S troubleshooting. Filament won't load, MMU2S clicks and squeaks?
For me the issue was the PTFE tube in the extruder. I accidentally used the larger diameter tube. Needed to use the smaller ID tube that creates better tips.
Mike