* NOT HAPPY! Adding / Changing filament mid print

[Keyemaster2001 0]

I am a little frustrated with my UM3+ ! For the money paid and to be a professional grade 3D printer why wasn't filament change written in the firmware? I have recent lost a 17 hour print due to not being able to route more filament in the printer. I really don't know why there is no load and unl0ad function during paused printing. Please make this a priority on the next firmware update.

[gr5 2,069]

You can just lift the lever on the feeder, pull out old filament, insert new filament. Right? Am I missing something? I don't use load/unload -- it seems like a lot of work for nothing.

Plus you can always continue a failed print. I know it's not written nicely into the firmware (like it is with UM2 tinkermarlin) but I've had multiday prints fail and have been able to keep the bad hot go to bed and the next day edit the gcode and continue a "failed" print no problem. It was an hour of work but saved me a day. I know - not a great solution and lots of work. But possible to do.

[Keyemaster2001 0]

The filament was past the insertion hole which made it impossible to grab. Is there a guide on removing filament showing this operation? IE,, Pause ,,, keep hot end temp.,,, Pull out C-clip ,, push down on silicone tube,,,, It seems like important information to me am I wrong?

[gr5 2,069]

You have to remove either end of the bowden when you get that.  Remove the little c clip and then PUSH DOWN on the outer ring while lifting firmly on the bowden.  Make sure the outer ring moves down a bit before pulling on the bowden - push quite hard - maybe use pliers if it doesn't move down.   It's safer to do it at the feeder end although in my experience with um2 one has to do it on the head end more often.  

I would mark the bowden with a sharpie or a knife for future reference so when you reinsert it then you can verify that it's all the way in.  When inserting again push DOWN on the outer ring, then push down on the bowden, then insert clip while still pushing down on the bowden.

That white bowden holder ring thing has 4 blades inside.  Metal blades.  You can see the mark they make on the bowden.  If you ruin your bowden you can buy more at 3dsolex.com. Or Ultimaker.

Edited January 8, 2017 by Guest

[neotko 1,417]

@gr5 you are missing the part about the core cooling down immediately after hitting pause, and the limited time window to swap, reinsert. Also the core retracts to the safe point where cooling down the material won't clog the core (automatic safety procedures of um3) and that when inserting new filament the firmware inverts that values to continue as better as possible after a pause, if the filament is pushed too far it will make a big blob on the print (ruining it) and if too short will leave an area underextruded.

So, seems easy, but isn't without a procedure on the firmware.

Afaik UM is working on this feature (saw it on a beta test in september). So, I would just wait, they plan to improve the user experience as much as possible.

[gr5 2,069]

>pushed too far it will make a big blob on the print (ruining it)

Yikes - I didn't think of that. One could remove the bowden at the head, mark it with a knife or pen, remove it completely, line it up with the new filament and mark the new filament in the same spot then insert new filament until line is at the top of the head. But still...

I'm not sure you have to do it before the nozzle cools as I think the filament is in the cold region anyway if it is doing a significant retraction before pausing.