UM3 extruder messed itself. ABS all over. How to clean-up?

[cotton9 0]

I apologize if this has been discussed in the forum before, but as you can tell from my title, I'm not sure how to describe it to look it up. I've only been printing for a couple months, but haven't had too many issues to deal with until today.

I starting a 6 hour print of an open-top cylinder (abt 20cm diameter) last night, black ABS (not Ultimaker), default Cura settings for "Generic ABS" (w/ glue stick). The first layer printed fine, so I went to bed. When I checked it this morning, the UM3 said the build was completed, but nothing was on the plate, and the material was an unrecognizable glob stuck all over the head - inside and outside. It's stuck, and it's a mess.

Is this common and does it have a name? Any ideas how it happened, how to prevent it, and how to clean it up? My initial thought is that there was adhesion issues because the default plate temp wasn't quite high enough for most ABS. I've tried heating the extruder to dislodge it, which loosened it a bit, but then I got a max temp error (probably b/c the fan can't hit the extruder). Unless I hear otherwise, my next step is to try and clean it up using a desoldering heat gun.

Any insight would be appreciated.

[gr5 2,173]

Do you have a heat gun? You need to get that mess up to about 110C. A bit hotter than boiling water. If you don't have one yet, buy a heat gun asap. A hair dryer might work actually - not sure.

Don't do unattended prints until you are an expert at getting parts to stick. Here's a (long but informative) video:

 

[cotton9 0]

Thanks for the reply,

I grabbed my heat gun, then put it down to double-check in the forum. Glad to have the method confirmed.

I haven't had any issues with sticking until this print. But I admit that I've relied heavily on the temps listed on the filament packaging and Cura plate defaults. This was my first time with this particular ABS, and I've since read that the default ABS plate temp is adequate for Ultimaker brand, but not hot enough for others. I'll try again w/ higher temps (and anything else that video says that I'm not already doing).

Thanks!

[cotton9 0]

For the record, in case someone finds themselves in a similar situation:

Cleaning this up was NOT EASY.

I ended up using a precision heat gun that's part of a desolering kit, using 250-300 C temps, with a variety of tweezers and pliers.

1) Unstuck the fan casing from the blob - This wasn't difficult w/ heat.

2) Dropped the fan casing out of the way and dislodged the blob - This was much more difficult than anticipated b/c two of the hotend wires were disconnected and embedded inside the blob. I had to slowly pick away the heated ABS to get to the deeper unheated ABS and eventually dislodge the wires.

3) Removed the ABS that squished itself on top of the heater block from the head - I couldn't slide out the extruder b/c ABS was sitting on top of the heater block, which prevented it from lifting. After about 20 minutes heating/picking this small section to remove the ABS, the hotend eventually fell off. As you can tell from the photo, the ABS had gone so far inside that there was no way I was going to be able to remove it all from above the heater block while still attached.

Can anyone tell what parts of this are salvageable vs. useless? Any tricks to clean up the last bit? Heat/picking/acetone?

[meduza 191]

What has happened with that print core is that you have broken off the heatbreak, i would say it is pretty useless in its current state.

[ultiarjan 1,223]

Indeed, your only option is to get a new core, but I would not trow the parts away. In time there may be 3th party alternatives or refurbish kits for which you can still use them. I don't know of any such initiatives now, but it just seems logical that someone will pursue this....

[gr5 2,173]

Get a new core. BUT DON'T THROW THIS ONE AWAY. You will be able to purchase just the broken parts some day. Do soak it in acetone overnight though to get the rest of the abs out of there.

[cotton9 0]

Will do - Thanks for the info!