Unload Filament with new SW (MK4s and MMU3) does not work
After my update to the new SW-Version (6.5.3 and 3.0.4) the unload of the filament after the print does not work. I have the nextruder with the "standard" sensor configuration (read contact). It did work perfectly with the old SW. But now after the print the filament is not retracted by the MMU and a "filament present" error of the filament sensor appears. After pulling the filament manually (without any force) the MMU is pulling back.
The same happens when I load the filament to the nozzle. This is working because I have selected the "standard nextruder". But unloading does not work.
Is there some configuration I need to modify?
RE: Unload Filament with new SW (MK4s and MMU3) does not work
If you are using MMU, you must also have an MMU type sensor mounted on the nextruder for proper function (with an auxiliary lever extending under the gearbox) and you must not have the "Standard" sensor selected in the printer, but always the MMU type!! When using the standard sensor on the nextruder, the wheels will push the filament out of engagement, but the filament will remain in the sensor! And that's why the MMU thinks the filament is engaged with the feed wheels and doesn't give the command to pull it out. And the fact that your probably incorrect sensor combination has worked for you so far is not the fault of the FW but yours.And if you start printing with the MMU, don't start printing with the filament in the nozzle, but have the filaments loaded in the MMU slots and leave everything to the printer to load the correct filament!
RE: Unload Filament with new SW (MK4s and MMU3) does not work
Why did it work before? And why is it not working now. Without any change on the HW it could only be a change in the Firmware.
RE: Unload Filament with new SW (MK4s and MMU3) does not work
And why did it happen to me, right? I was expecting exactly this reaction! And as I wrote last time, the fact that it worked for you was just a miracle caused by the meeting of countless lucky circumstances! A change in FW can come at any time and no one will look back at one user who, moreover, does not have correctly assembled HW for the correct and guaranteed function of the device! It was enough to change some limit value somewhere, which is important for the better function of tens of thousands of printers that are correctly assembled! Well, you will have to adapt and mount the changed sensor for use with MMU on Nextruder, if you want to use the new FW functions not only now but also in the future! And if you contact support with this problem, their answer will be the same as mine.
RE: Unload Filament with new SW (MK4s and MMU3) does not work
Rebuilding the sensor to MMU should not take more than one hour. If you purchased the MMU from Prusa, you should have all the necessary parts for rebuilding the sensor included in the package and the instructions for rebuilding can be found in the MMU assembly instructions!
RE: Unload Filament with new SW (MK4s and MMU3) does not work
I had the new sensor implemented. But TPU was not working. So I need another solution.
RE: Unload Filament with new SW (MK4s and MMU3) does not work
If I understand this correctly, unfortunately, in my opinion, you can forget about printing TPU using MMU. MMU cannot handle this and is not intended for it. And if you want to print TPU separately, you need to loosen the sensor clamping screws to start with so that the pressure rollers do not deform the filament. In fact, you do not need to accept the recommendation to align the ends of the screws in the pressure nut at all, but tighten them just enough so that the filament is securely held, but no more! And so that I do not forget, when printing with one filament (without MMU), when inserting the filament with this sensor, you need (unlike the original sensor) to first select "Load filament" in the printer menu and only then insert the filament into the hole on the top of the sensor. This is important so that the extruder wheels start moving and introduce the filament. However, nothing prevents you from having the filament inserted in the MMU and starting printing as multi-color. In this case, the printer will introduce the filament itself and start printing. And there are a lot of discussions and recommendations here in the side threads on how to adjust the printer for TPU printing. But you certainly know this, judging by the number of your posts, this is not your first time here.
RE: Unload Filament with new SW (MK4s and MMU3) does not work
You are right - I'm a bit long in the Prusa hemisphere.
I was hoping there is a fix for this problem, like the extra load distance I'm using to feed the filament into the "standard" Nextruder.
TPU might work for TPU allone (which is 99,9% of all my TPU prints). I was able to produce hinges with TPU and PLA. A rather rare application, but sad that it was once possible and now with a new (supposingly better) SW it is no longer able.
To comfort me: Bamboo fails also with TPU and PLA in one print
RE: Unload Filament with new SW (MK4s and MMU3) does not work
Well, maybe it will be necessary to play with the settings here too. Just to explain the difference between the two types of sensors. The "standard" works by waiting for the filament to appear in the sensor. The sensor is actually "above" the feed wheels and at this moment the wheels in the extruder start rotating and at the same time it gives the MMU a command to stop pushing the filament into the printer, on the MMU the selector roller turns to the neutral position and the extruder feeds the filament into the nozzle. With the MMU sensor it is different. The printer receives the command to load after the filament passes FINDA on the MMU. Upon this command the extruder wheels start to rotate slowly and wait for the filament. The filament is then caught by the slowly rotating wheels in the extruder and moves on. And only when the pressure rollers deviate and the lever moves to the left does the sensor react to this, switching to the "filament loaded" state. This gives the MMU a command to stop pushing the filament into the printer and on the MMU the selector roller turns to the neutral position and the extruder feeds the filament into the nozzle.
RE: Unload Filament with new SW (MK4s and MMU3) does not work
Right. In the "standard" configuration the sensor has some distance from the nextruder wheel. To overcome this situation the "extra loading distance" in the custom g-code tells the MMU to push further after the sensor has triggerd. During the unload the nextruder pushes the filament until there is no more to travel and the MMU had, in the previous SW, pulled the filament slowly until the sensor had given signal that the filament was unloaded.
Now the loading procedure works as before. But during unload the MMU did not pull the filament, is reading the sensor and nothing happend.