Filament change during prints
I am trying to print some game tokens. They have at least three "layers" of colour or 2 filament swaps. I've been using Prusa Control to slice and set the colour changes. However, a few issues arise occasionally.
1) the printer does the "push the button to auto-eject" and nothing happens. It continues to beep at me and pushing the button does not eject the filament. It doesn't happen everytime; just occasionally and it feels like this happens when I try to merge two STLs into one print but I don't know for sure.
2) the printer no longer autoloads a certain filament. I had picked up a few sample packs and the one colour is on it's last 15cm or so and I was wondering if length mattered.
3) the extruder squirts a few cm of filament between the colour switch confirmation and the print. Usually i can grab it but occasionally it drags into the object so I pause the print, remove it as carefully as I can and resume. Is there some trick or setting I'm missing?
Re: Filament change during prints
I'm not sure about #1. I'm guessing #2 is because you have a MK3 and not a MK3S which the filament sensor is not really compatible with a lot of the different filaments. I have to turn my filament sensor off on mine because it wouldn't see filament sometimes. One of the main reasons I upgraded to the MK3S stuff.
As for #3, I think there is a trick. And I seem to remember dealing with what you are dealing with and getting the hang of it.
When there is a color change it moves the head to the front right corner of the bed and asks to change the filament, it extracts, and then inserts new filament. And when it inserts it extrudes a couple CM's of plastic, hopefully making a cone on the bed. Once it's done it asks if the color change has been successful. What you want to do is grab a pair of tweezers (or needle nose pliers) and grab on to the cone (or pile of extruded mess of old/new color) and while holding that extruded mess in place (don't remove it from the bed yet). THEN and while you have a hold of the extruded waste, then push the button on the control panel. It will then extrude a bit more plastic, and then retract slightly and if you continue to hold the extruded waste with the tweezers at it's location on the bed (don't remove it from the bed). Let the head move away from the extruded waste. Then head will move back to the print and it will not drag any old color to the object.
I probably described that terribly. 🙂
Re: Filament change during prints
Sorry, I should have specified that it is a kit MK3s.
I've been removing the "cone" but I'll try just anchoring it and seeing if the squirt catches on that. Hopefully this becomes a thing of the past if I get a MMU.
I do have another question about the filament change. I had a short length of filament which was shorter than I anticipated. The end disappeared into the head but the printer kept printing. I checked the support>sensor info and it read:
PINDA: 0
FINDA: N/A
IR: 0
I took the zeros as out of filament. I aborted the print but it turns out there was still some filament in the extruder (but not enough to autoeject).
So, my assumption is that the sensor can read "no filament" but the printer still prints and, if I had waited longer it would have asked for more filament when it actually ran out.
(Lesson regardless, pause > visually check and then abort or continue)
Most of my issues are around filament changes now that I have the "keep the sheet clean" routine down. It printed a great Hero Forge 28mm figurine in one colour much better than I was anticipating. So I'd really like to get over this hurdle.
Re: Filament change during prints
Margaret I see from the Finda mention that you are using a MMU2 or 2s so you might want to post this in the Forum section for the MMU users....
https://shop.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-f52/
Better chance of finding folks with similar machine setups.
Re: Filament change during prints
No, it's a straight MK3s. Apparently they put the potential for a MMU into the brain which is why mine said FINDA N/A. However, it did confuse the heck out of me because I figured that was my problem - my FINDA was offline.
According to tech support there is apparently a zone of time when the sensor thinks there's no filament (IR=0) but the printer knows there's still a few cms left to print or eject. My mistake was to abort instead of letting the machine tell me it was actually empty. Which I have been assured it does.
But thank you for the redirect. We're thinking of getting an MMU and that forum will be of interest 🙂