RE: MK3S/MMU2S not loading filament on print
john are you printing from SD card or USB?
RE: MK3S/MMU2S not loading filament on print
john are you printing from SD card or USB?
I haven't print anything from MMU2S. I was trying to load the filament to nozzle and I ran into the problem. I have been trying to fix it for almost 2 months now (I was working at it during weekend, not weekday).
I'm taking apart the extruder now and I took a good look at the sensor. That got me wondering and wanted to ask a question - Am I supposed to tighten the extruder idler spring screw to make the idler arm go deeper inside the sensor area? If my question make sense (English isn't my first language).
RE: MK3S/MMU2S not loading filament on print
Updated (sigh).
I believe I have found the culprit: PINDA sensor that is DEAD.
After reading everything I can find on Google, people kept mentioning the sensor "trip" (an example, you can find whether sensor detects filament going through FINDA or PINDA in Support Info/Sensors) - so I checked that. I put a filament in MMU2S and FINDA showed "1". Then I put a filament in Extruder - PINDA showed "0". So that explains the all issues I'm having. I even took Idler off and trying to use it to trip the sensor and it's still showing "0".
I just sent an email to the Prusa support center. Hopefully, they can help me with that. ☹️
Now off to printing with my brand new MK3S!
RE: MK3S/MMU2S not loading filament on print
PINDA has nothing to do with the filament, it detects being close to the steel sheet.
Did you mean IR sensor instead?
RE: MK3S/MMU2S not loading filament on print
PINDA has nothing to do with the filament, it detects being close to the steel sheet.
Did you mean IR sensor instead?
lol, I was confused with PINDA and IR. Yes, I was speaking of IR sensor.
RE: MK3S/MMU2S not loading filament on print
Double check the plugs on both ends to make sure they are correct.
If they are and you have a multimeter handy you can check the function of the board.
- Remove the top cover of the tower so you can get to the sensor.
- Turn the printer on.
- Test the (facing the printer) right most pins and you should see 5v.
- Test the left most pins with nothing breaking the sensor plane and you should get 0v.
- Test it again with something breaking the plane and you should get a job zero reading (pretty sure it's 5v, but not positive).
- Break the plane while watching the IR value in the sensor status.
If all that passes then the sensor and rambo should be good. If that is the case then the issue is simply adjusting the tower and idler door.
If something doesn't test right, that will help Support identify what part(s) you need.
RE: MK3S/MMU2S not loading filament on print
Double check the plugs on both ends to make sure they are correct.
If they are and you have a multimeter handy you can check the function of the board.
- Remove the top cover of the tower so you can get to the sensor.
- Turn the printer on.
- Test the (facing the printer) right most pins and you should see 5v.
- Test the left most pins with nothing breaking the sensor plane and you should get 0v.
- Test it again with something breaking the plane and you should get a job zero reading (pretty sure it's 5v, but not positive).
- Break the plane while watching the IR value in the sensor status.
If all that passes then the sensor and rambo should be good. If that is the case then the issue is simply adjusting the tower and idler door.
If something doesn't test right, that will help Support identify what part(s) you need.
Yes, checked everything. Thank you for suggestion. 😀
I got responded from Support, he suggested me read this: https://help.prusa3d.com/article/wprwemqsmj-ir-filament-sensor-calibration and it turned out it fixed the issue.
One thing I don't like the way they designed the chimney - it was too difficult to keep the chimney to right because of limitation of single screw that would stay in single position. They should have made chimney more adjustment-friendly - like slide to right or left to make it easier to calibrate the IR sensor. I had to force push my chimney to right and tighten the screw. But the sensor test kept changing "0" and "1" if I sightly touched the chimney.
I would worry about during the printing and if it had to change to different color filament and it probably making some vibration and chimney could slowly knocked back in position and screw up the sensor.
RE: MK3S/MMU2S not loading filament on print
If it's changing it's reading with you tapping on the tower, then you are definitely going to have issues printing with it. You need to work on it some more and that may mean you night want to reprint your door as the flag might not be quite right. There is a modified door available (the page my sig links to links to the door) with a larger flag that you can shape to fit better.
I know it doesn't seem like it, but once you get it positioned right, that one screw will hold it in place just fine. It's the getting it in place that is a PITA.
RE: MK3S/MMU2S not loading filament on print
But the sensor test kept changing "0" and "1" if I sightly touched the chimney.
Did you try my modified version of the idler door? I redesigned it because I was having the exact same issues. The modified version fixes it by moving the pin for the gear .75mm closer to the door and reducing the size of the area surrounding the pin so it has more clearance for closing.
RE: MK3S/MMU2S not loading filament on print
I haven't tried Sneaks modified one yet. Originally, I had Sneaks modified Idler installed when I moved chimney to right and it didn't trigger the IR sensor. And then I switched back to original one and got it working.
I will work on it tomorrow along with all 5 filament test - I will put the modified version on it.
RE: MK3S/MMU2S not loading filament on print
I'm one of the lucky guys who is printing with MMU2s almost on daily base. Feel free to check it out https://www.instagram.com/3dprintingspirits/
Nothing I can say would ease your pain. Been there and understand what you're going through. The chimney design with the IR sensor need to be perfectly adjusted. There is no space for any errors. So first of all make sure the IR sensor is not moving by itself. The plastic cap doesn't press it down like it should. As the next step make sure the sensor triggers after around 0.75mm filament width is inserted. Otherwise you might get fast back and forth switching values during operation and load/unload. To make it more complex make sure this is happening with correct idler screw tension. Be prepared to adjust this if needed. This is something you might see during first prints.
This is the most important step in the whole MMU2s assembly. If this sensor is not working correct, you will get very strange and funny errors. It decides if the MMU2s will stay on the printer or put back in the carton (in rare cases even further).
Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram
RE: MK3S/MMU2S not loading filament on print
You're lucky... Unfortunately for me to struggle with that - at least, I learned lot from it.
As today, I finally managed to get calibration corrected. I noticed the MMU2S first print calibration is different from my new MK3S - filament seems smaller than MK3S.
My next target: get all 5 filament in and see if it worked correct. But that will be next weekend - I'm bit busy with real life.
RE: MK3S/MMU2S not loading filament on print
The space between the filament going through the MMU2S bondtechs is to loose... the filament is not picked up by the MMU2S it just slips through the bondtech and the wheel guiding it from the top.
If I help the MMU with putting the filament to the printer there is no problem with printing.
So I now only have a bondtech mmu issue how can I get this resolved ?
RE: MK3S/MMU2S not loading filament on print
@christian-h7
I thought Id just quickly share my solution to this as it might help someone without altering the shape of any parts.
I think I had sort of the same problem. Basically no filament ever left the MMU. There was low resistance and loading was otherwise ok. Was sure I had the sensors nicely tuned, but turned out that the IR sensor startet triggering from the movment of the bondtech gears in the extruder as soon as the MMU started to load to nozzle. So the loading stopped, naturally. I wasnt able to detect this when trying to calibrate the IR.
To solve it I simply moved the tower as far left (away from the door) as possible, and tightened it really good in that position. The IR was 1 wihtout filament then. Then I tightened the spring loaded screw until the sensor went to 0, and then even som more and way more than the manual says. 3-4 threads outside the nut. This holds the door tightly fit and allows the bondtech gears to move without triggering the IR. Havent had any trouble with filament not going through to the nozzle since. This is on MK3S MMU2S with latest firmware using prusament pla. Havent tried other materials yet. Crossing my fingers this wont give me other problems later on, but it wouldnt surprise me 🙂
Good luck
RE: MK3S/MMU2S not loading filament on print
@sneaks
Thanks sneaks, I'm starting to think this will solve my problem also....however, I can't print it...catch-22...sigh.
RE: MK3S/MMU2S not loading filament on print
@mractor1
Bypass the MMU, you should be able to print as a normal MK3 if the MMU is not working properly.
RE: MK3S/MMU2S not loading filament on print
Seems like I'm having similar issue. It seems like MMU2S and Extruder are doing tug of war after few seconds of loading filament. I couldn't pinpoint which MMU2S or new Extruder that caused the issue.
I know this is an old post, but I wanted to reply because I experienced this also. It seems if the MMU2S tensioning screws are too tight, the MMU2S idler won't rotate to the correct position and remain stuck on a bondtech gear when it shouldn't be. My solution was to loosen the MMU2S tension screws just a little bit. Instead of their heads being just below the surface, they are level with the surface. The tug-of-war problem stopped. The MMU2S seems incredibly sensitive to the tightness of these screws.
RE:
@pjr mentioned a extruder part assembly which does make sense due to the parts lying around after "assembly" but while reading the instructions I couldn't find any steps for this even though there are parts left.
Didn't took me to long to install all parts but I was searching for the (in the instruction mentioned) extruder assembly and gave up after searching a while because it worked at first. Now I'm running into some problems and did see you make a photo I've never seen before. Is there any link you could provide? I'm sorry if this is stupid but I'm just not able to find or see it anywhere... ):