MK3S filament stuck
Hi,
I completed my MK3>MK3S upgrade yesterday and calibrated it this morning.
I dialled in the Z, everything looked great.
I started to print a PLA Calicat .. it printed about half of it and then just stopped feeding the filament (no clicking, just wasn't feeding - but the bondtechs were moving okay). I noticed this after a while and stopped the print. I opened the idler door, heated the hotend to 280 and gave a gentle and then not so gentle tug - the filament wouldn't' budge.
Then it snapped off as you can see here:
Would anyone have any suggestions as to what I do from here (and why it stopped feeding).
I have a horrible feeling I need to take the whole thing apart again, don't I?
Thanks
Re: MK3S filament stuck
For one, looks like the gear on the motor wasn't installed properly. Loosen both set screws, ensure one screw is perpendicular to the flat on the shaft - tighten it. then tighten the other set screw, which acts to jam and lock the flat screw to the shaft. Flat First, as they say.
Check the other gears on the printer; they also need to be assembled flat first.
You'll need to remove the nozzle to clear the filament. Heat the hotend to 280c, loosen the nozzle an eighth or quarter turn. Let things cool to around 100c, then remove the nozzle and hopefully the filament will come out with it. If not, it's a full hot end disassembly.
Be sure when reassembling, install the nozzle - and tighten it against the heat break (HEX should not touch the aluminum block), then you heat to 280c and do the final torque.
ps: read here for a recent experience ...
https://shop.prusa3d.com/forum/hardware-firmware-and-software-help-f64/request-for-enhancement-make-e3d-fully-replaceable-t28513.html
Re: MK3S filament stuck
I've just had a similar jam and snap half way through the second benchy after a 3 to 3s upgrade.
I can't get the bit of filament through by pushing with a 1.5mm metal bar and I can't get a needle up the hotend
Will report back....
Re: MK3S filament stuck
I tried the removing the nozzle and pulling from the bottom - no joy
I did heat it all up with the nozzle out and managed to push some of the filament through and then it stopped again.
I've also realised the white Prusament PLA I was using is super duper brittle - fresh out of it's bag
I guess its a full disassembly
Re: MK3S filament stuck
Turns out the MK3s hotend removal is not unpleasant.
I took the fans off, took off the hotend cover with two screws off that was under the part fan (I took the fan support arm off) and then took the two screws holding the extruder motor out from the other side of the printer at the top - one of them held the sprung door for the bondtech.
I then heated it up with the hotend hanging in space and then unscrewed the heatsink.
It took the metal tube that buts against the hotend out of the heatblock so I used two M6 nuts against each other to get it out of the heatsink
I could not pull the ptfe tube out of that and see the blockage in the tube.
Baked it at 250c and used a bit of 1.5mm wire to push the lump out. Backed again and used some twisted wire to clean the hole - it looked super clean anyway.
Put it back together (with thermal paste) and it seems to work better than ever
I've bought a 1.75mm hand reamer in case it happens again and I'm wishing I could get new 60p ptfe tubes without a £12 delivery charge from prusa...
Still not sure why it happened. I've dried the white filament and I did notice a strand of black plastic where the ptfe met the metal inside the heatsink.
Been checking the heatsink with pla and its less than 50c all the time
Re: MK3S filament stuck
After printing a bunch of parts in pla and pet its just blocked again with the white Prusament
The filament snaps there as it grinds on filament once blocked.
Will contact support I think
Re: MK3S filament stuck
Post a photo of the heater block with nozzle installed.