UM3 both print core's completly destroyed

[korreander 0]

hi @ All

 

UM3 was doing a print job when there was no material left through the core1 print.
I noticed and stopped this.

Unfortunately, all around the printcore under the cover was Materal, see pictures.

 

Does anyone have similar experiences?
What could be the cause?

 

 

 

Edited March 21, 2019 by korreander

[starbuck 25]

I've had this blobbing happen to me a few times now. Typically, the extruded filament didn't stick to the bed well enough, the printer was still extruding and filament had nowhere to go but up (into the head). I usually clean this very slowly by heating the head up, picking away any melted plastic I can get to, then taking apart the head and finally using a heat gun to heat up the plastic to peel it off. It takes a lot of patience to do and have a good printcore afterwards.

[gr5 2,265]

This is called a "head flood".  It's somewhat common on UM3 and S5.  No one knows how common.  It's never happened to me and I've been using the UM3 for years and S5 since it first came out.

 

UM considers cores to be "consumables" like filament (costs about the same as 3 spools of UM filament).

 

You could consider a 3dsolex core which should last longer but you broke these at the heat break which is not any stronger on the 3dsolex cores.

 

The cause of a head flood - there are 2 possible causes:

1) Your part comes loose from the bed during a print at a moment when the part is wider than it is tall.  The head then carries the part around like a hockey puck.  People tell me this is the most common cause by far.  The solution is to NEVER have parts come loose from the glass.  I sometimes have chunks of glass embedded in my print, but my prints never come loose.  I have a video of how to achieve this if you are interested.

 

2) The door fell open and it started extruding into the door.  You may have weak magnets or they might not be touching the vertical screw or maybe your door is not angled properly (you can bend the metal portion of the door such that it closes better).  You can pry the magnets out 0.5mm and that might help.  

 

 

It's hard to tell the difference between #1 and #2 because in both cases the door is open when you come back to the printer.

[gr5 2,265]

@starbuck - you should never get a head flood.  Here is some complex and important advice to keep your parts from ever coming loose again:

 

 

[starbuck 25]

@gr5 I work with college students who are not always 100% trained on these machines like you and I probably are. Plus with 18 UM3s and 6 UMS5s I see some of the small statistics like how often head floods pop up. I'll be sure to watch your video still! I'm always training my staff to look out for things like when parts are peeling up or underextrusion so maybe I'll find more training material for them.

 

The magnets were my cause at least 3 times. I bent the frame of the head back into place so they had a stronger grip which fixed the issue. Also stuff like this exists for that reason https://www.thingiverse.com/thing:2658960