Removing filament problem  

Re: Removing filament problem

You should always preheat to the temp of the filament that is loaded. You can use the Setting menu to adjust higher if needed. Make sure you are pulling up with steady pressure when you select the unload and it should pop right out.

Re: Removing filament problem

Thanks! The filament unload has been ok other than that one time (Have tried 3 different PLA and 1 PETG) .In the hindsight I really should have paid attention to temp . I was just surprised how hard it got stuck and I couldnt remove it at all.

Re: Removing filament problem

The filament always seems to get a hardened glob inside that jams.

The only way that I found to remove it is to have the extruder heated up and move the filament forward a bit to melt the glob then unload the filament.

I do this:

1) Preheat nozzle to temp of filament (Settings, Temperature, Nozzle) or how you want.
2) Once up to temp. Move the extruder motor forward 3 clicks (Settings, Move axis, Extruder, 3 ). Little bit of filament might come out.
3) Go back to main screen Unload Filament.

Re: Removing filament problem

So the filament that you were removing required 230 or the filament you were loading required 230? If you only heated it to 215 and you were removing the filament that required 230 that would explain the clog.

When changing filament here is what I do: preheat to the filament temp or slighter higher, extrude a little, then do the unload quickly pulling the filament clear before it starts cooling down.

Re: Removing filament problem

When changing filament here is what I do: preheat to the filament temp or slighter higher, extrude a little, then do the unload quickly pulling the filament clear before it starts cooling down.

Chris, what's the manual method for extruding? Didn't know there was an option and will have to look for it.

Re: Removing filament problem

I still use the unload function, but as the motor is extracting it I'm ready to pull it once the motor stops moving. The timing takes some practice but if you wait too long after the motor stops it will cool and get stuck.

Re: Removing filament problem

Settings > Temperature> Nozzle = maximum temperature needed (eg 230)
Settings > Move Axis > Extruder = ~5 to 15mm
Unload Filament
Prep new Filament
Load Filament

What this does is get your nozzle ready for the new filament - worst case is your lower-temp PLA flows a bit too much which is fine since you're just unloading. Extruding a few millimeters makes sure that there's no small blob gathered in the cooled nozzle. It's too easy for a bit of extra pressure to build up and, when it cools down in between prints, create a plug that's hard to pull up through the upper ptfe. You should have plenty of time to Unload Filament, new pressure won't build up (significantly) and cool if you're not extruding any further.

Short version - push a bit of filament through before unloading.

Works every time. Got lazy just this morning, didn't follow the procedure and sure enough had to yank to free the filament. Also different revisions of the firmware have handled unloading differently, sometimes faster sometimes slower, and maybe filament sensor plays a part but I don't run that so can't say.

Re: Removing filament problem

So the filament that you were removing required 230 or the filament you were loading required 230? If you only heated it to 215 and you were removing the filament that required 230 that would explain the clog.

When changing filament here is what I do: preheat to the filament temp or slighter higher, extrude a little, then do the unload quickly pulling the filament clear before it starts cooling down.

The problem here was that the it was stuck in the part between the top end and the motor pulleys. So heating the hot end had no effect and it was well and truly stuck. I really tried multiple ways but that thing wasnt going to move 🙂

The filament I was removing was 230 . I hit preheat and then just tried to pull it off..

Re: Removing filament problem

Settings > Temperature> Nozzle = maximum temperature needed (eg 230)
Settings > Move Axis > Extruder = ~5 to 15mm
Unload Filament
Prep new Filament
Load Filament

What this does is get your nozzle ready for the new filament - worst case is your lower-temp PLA flows a bit too much which is fine since you're just unloading. Extruding a few millimeters makes sure that there's no small blob gathered in the cooled nozzle. It's too easy for a bit of extra pressure to build up and, when it cools down in between prints, create a plug that's hard to pull up through the upper ptfe. You should have plenty of time to Unload Filament, new pressure won't build up (significantly) and cool if you're not extruding any further.

Short version - push a bit of filament through before unloading.

Works every time. Got lazy just this morning, didn't follow the procedure and sure enough had to yank to free the filament. Also different revisions of the firmware have handled unloading differently, sometimes faster sometimes slower, and maybe filament sensor plays a part but I don't run that so can't say.

Great Tip! thanks. Will do this from now.

Re: Removing filament problem

I also took a drill while assembling the MK3 with a 2mm drill and then drilled out the filament path above the motor. Because it was quite tight on the filament and also the hole was not 100% round. Since then I never had to worry while unloading.

But I think extruding a small amount just before unloading is a good idea, too. Whished the MK3 would do that automatically if that really helps....

Re: Removing filament problem

Junk machines like the DaVinci brand even extrude before auto unloading filament. This seems to be another quirk that PR overlooked when hurrying to release a hardly tested machine.