MK4 randomly unloading filament during prints?  

RE: MK4 randomly unloading filament during prints?

I discovered the power cord was loose - but also support recommended I stop using the alpha slicer release and use 2.5.2 or the latest stable release. Trying it again here. 

RE: MK4 randomly unloading filament during prints?

My MK3S+ also ejected filament during a print - again using the Alpha 6 slicer for 2.6v. I went back to slicer 2.5.2. Seems to have solved this weird problem so far. It's strange though I've printed many prints with the alpha slicer with no issues. Why now suddenly? 

RE: MK4 randomly unloading filament during prints?

This may seem silly but are you accidentally inserting pauses into your prints in PrusaSlicer and not realizing it?

RE:

I have the same problem. looks like problem with filament sensor. but I don ‘t found filament sensor yet,  as well no manual showing it. looks you have fixed it. going to print another part, as well to slice and print, change slicer,  to test if it is hardware or software problem.

RE: MK4 randomly unloading filament during prints?

A pause shouldn't automatically unload the filament.....

Posted by: @brutusboots

This may seem silly but are you accidentally inserting pauses into your prints in PrusaSlicer and not realizing it?

RE: MK4 randomly unloading filament during prints?

I have the same problem.

At first I though I had some colour changes in the gcode by accident bu that wasn't the case. In my case this only happens with a light gold/yellow coloured filament of a certain brand. I am going to check if the filament sensor can be disabled for the MK4.

RE: MK4 randomly unloading filament during prints?

Since new - I have had issues with the filament sensor on the MK4 - false reporting "no filament" - I contacted support - recommendation was to open the filament door and blow out the drive gear area - no change.  Found that as I rotated the filament - ie, from 270 deg to 180 deg, or from left to facing forward - the sensor would indicate "no filament" - in desperation - I removed the 3 screws that hold the planetary gears in place on the front of the extruder - removed the planetary gear set - reinstalled the drive gear/planetary gear set - that must have dislodged material I couldn't see - because the filament sensor is now working correctly - ie, the filament can be inserted and rotated 360 deg - remains detected!  As an FYI - this is a factory assembled printer - and I am not recommending anyone disassemble their printer - but this worked for me....your mileage may vary....

RE: MK4 randomly unloading filament during prints?

I just completed assembling my MK4 this past weekend, and ran into this same issue with my first print using PLA. The print was about 20 minutes in total, but the filament auto ejected about halfway through the print. Interestingly enough the filament color was light gold/beige in color, similar to what Marcel V reported having issues with. I've since printed over 15 hours using black PETG and have not run into the problem again, so it definitely appears that the light gold color filament causes problems.

I'm curious though why the filament would auto eject? Shouldn't the printer pause and ask you to press the button before ejecting filament (similar to what the MK3 does)?

RE:

I have the same problem. Printing yellow petg om MK4

Slicer 2.7.1 and firmware 5.1.0

RE: MK4 randomly unloading filament during prints?

same issue here mk4 with Slicer 2.7.1 and firmware 5.1.0

RE: MK4 randomly unloading filament during prints?

Same issue. Trying again with filament sensor disabled.

RE: MK4 randomly unloading filament during prints?

Same on my MK3S.