Blob residue: Leave it alone or remove it all?
I'm STILL sorting out bed adhesion issues with my new-ish Mk3. This morning, I woke up to find that an overnight print had come un-stuck and blobbed the printhead.
Removing the blob was comparatively easy. The only obvious damage was to the fan guide at the bottom of the printhead: I had to take it off to get at the blob, and when I unscrewed it, the screw mount cracked off. It was quick to repair with superglue, and I'm hoping that holds up long enough to print a new one.
Questions
(Happy to get a link as an answer; Not asking anyone to type all this stuff anew.)
1, the key question)
Is it better that I really get in there and clean off every remnant of the print blob? Or is it better to just leave well enough alone, since it seems to be back to basically functional, and not risk going into the head with tools? Or a bit in between: Clean off certain critical areas, avoid messing with others?
2)
What tools and techniques WOULD you use to clean off the blob residue?
3)
Do you think the screw mount on the fan guide stays cool enough that the superglue repair will hold up long enough to print a new one? (Assuming I run some other basic prints and tests before getting around to trying to print a new fan guide.)
Re: Blob residue: Leave it alone or remove it all?
Wish someone had a picture of a Blob attack on a 3D printer in action, but wouldn't want someone to intentionally ruin their printer. Looking at that mess especially the last photo it looks like the filament is pouring down from the heat break area between the heat sink and the heater block.
Could this have happened or does the blob just form around the heat break and the inside of the blob next to the heat break is melted.
If the EXTRUDER is not put together properly can you have back flow seeping out here at the heat break if the nozzle get's clogged? Path of least resistance right?
In the last photo you see the more solid plastic going away from the edges, but on the heater block it melts down over it like a lava flow. Gravity pulls the flow downward.
Sorry, this subject makes me think ways this is caused and what you need to do to keep it from happening.
Re: Blob residue: Leave it alone or remove it all?
From some ideas I've read previously on these forums people have using hair dryers/heat guns to clean up after a clog. I would remind you that there are a lot of plastic pieces there and would remove the E3D hotend from the E-axis.
If you bought your printer assembled now would be a good time to use the online assembly instructions.
5. E-axis assembly
Step 18 Inserting the E3D hotend
Re: Blob residue: Leave it alone or remove it all?
I have a soft wire brush that I use to clean off the print head when I get a blob. But you have more than a minor blob. I don't think I'd use the wire brush around the heater or thermister. Those can be fragile.
Re: Blob residue: Leave it alone or remove it all?
looks like this was a serious Blob!
I would loosen the E3d V6 assembly, from the extruder plastics, carefully, and endeavour to remove the waste plastic from between the heat block and the cold end heat sink, otherwise you are likely to mess up the functioning of the heat break, with resulting extrusion problems.
be extremely careful of the thermistor wires and heater wires,
a heat gun, may help you remove the remnants of the Blob...
be careful not to overheat the extruder housing plastic parts.
be careful of the fan blades
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Blob residue: Leave it alone or remove it all?
I've tried loosening it with a small heat gun (a sparkfun heaterizer) but the PETG structure around the PLA blob residue became soft and begun to move as well, long before my IR thermometer said either should be melting.
Re: Blob residue: Leave it alone or remove it all?
I've disassembled a bit more of the head, and tried to get the E3D assembly out (re: Joan & David's suggestions). However, the blob is bonding to both the E3D assembly and the plastic housing,
Firm-but-gentle pressure isn't enough to re-separate them. Also, the thermistor and heater wires are embedded in the blob.
Any thoughts on how to get all that separated? (As I mentioned in the last post, trying to use a heat gun to melt the PLA also softened the PETG housing enough to cancel that attempt.)
Re: Blob residue: Leave it alone or remove it all?
I've disassembled a bit more of the head, and tried to get the E3D assembly out (re: Joan & David's suggestions). However, the blob is bonding to both the E3D assembly and the plastic housing,
Firm-but-gentle pressure isn't enough to re-separate them. Also, the thermistor and heater wires are embedded in the blob.
Any thoughts on how to get all that separated? (As I mentioned in the last post, trying to use a heat gun to melt the PLA also softened the PETG housing enough to cancel that attempt.)
ugg. looking at the thermistor and heater cartridge wires encased in that makes me shudder. They are not long for this world i fear.
instead of using a broad based heater like a heat gun or hair dryer I would try heating up the block and see if that will loosen it some and other than that maybe a soldering iron to keep your heating more contained. I would be extremely careful around the wires.
Good luck!
Re: Blob residue: Leave it alone or remove it all?
Thanks for the advice, all.
Maybe I just leave the wires in the blob? Clear as much of the blob off the heat break as I can, but leave the wires as they are? It seems like the cure is worse than the disease, insofar as we're talking about trying to clean the wires.
Re: Blob residue: Leave it alone or remove it all?
...and after dissassembling it down as far as I could get it with some of the parts glued together by the blob, I can see that I'm not going to easily recover this hotend.
I've gone ahead and ordered another one.
My only regret from the process was back at the start I didn't put the fan guard back on and at least TRY to print some replacement parts for the extruder structures before tearing it down to clean it all the way. I'd still be ordering new parts, but maybe not as many, and there was pretty much no downside to trying.