advice needed - solid abs on extruder assembly

[sethcluett 0]

Hello, so I have a doozy of a first post:

 

tl;dr: look at the photo - how do i get this hardened ABS off the print head?

 

Over the weekend, without asking, a student replaced the filament on our S5 from Ultimaker Branded PLA to a generic ABS he found. 

 

I arrived Monday morning to discover the horror show in the attached photo: Hardened red ABS had popped open the print head and the build-up caused the x-y limit switch error, since it can't reach the corner. 

 

The ABS does not want to release from the print head.

 

My instinct was to heat up the extruders and pull the abs loose, but the chunk facing the rear of the machine won't let the print head start-up calibration run, so i can't get past the error to head up the extruder. 

 

what i've done:

I have been careful to not use too much physical force, but what i have done hasn't worked.

I started to use an x-acto knife to remove the chunk that is preventing start-up, then thought I'd reach out to the forums and ask about best practices here.

 

Would acetone work? Am I right to think a heat gun would risk melting the print head enclosure plastic?

 

Any advice or war stories welcome. 

 

Thank you.

 

[Smithy 1,144]

Sorry to see your print head looks like this, but it happens more often than you think. When the object comes loose during the print, then the head moves the object around on the bed and the filament can fill up the head. To prevent this in the future, always check your bed adhesion, especially when someone uses ABS. And also important that the silicon cover in the print head is in a good condition.

 

You can only use a heat gut to carefully soften the material. Be careful not to soften the rest of the head, but it should work to get out the ABS block. 

 

If you want to try if heating up the print cores is enough, I don't think so, but you can try it, then just press the stop switches by hand in the left back corner, to "fake" the homing. I think the order is important, which of the two switches must be pressed first.