Large Blob Issue (Requiring Hot end disassembly)
Hello everyone! So I have dealt with blobs stuck on the extruder (we all go through this once a while) but I woke up this morning to a very unpleasant surprise of the biggest one yet (nicknamed this alien poop). This issue was preventable and the fault was on my end (Should've done the weekly Z axis calibration and taken care of the bed)
I managed to pull off the large portion of the blob, eh hem "alien poop"
I was printing in PETG which caused the blob to stick onto the printed parts of the hot end and cause some warping and minor damage when I pulled it off. I decided unplug all wires from the control board, and to just take apart the hot end because the plastic has seeped up pretty far up the heating block
I want to induce as minimal damage as possible, so should I just use a heat gun and slowly make my way through on the heating block? Also my dad has a i3 mk3s too, so shall I reprint the plastic parts in PETG or use the older ones with some minor damage. Before I do anything I want to hear your suggestions so I can fix this stressful situation as best as I can, thanks!
Best Answer by jsw:
OUCH! That looks like the worst I've ever seen.
Somebody ought to make a gallery of these.
The worst I've had are smaller ones which successfully came off using nozzle heat, gravity and a bit of gentle persuasion.
Soon after I started reading this forum I heard the horror stories of the Blob Of Doom ruining extruder parts, so when the local 'makerspace' closed up due to the pandemic, I printed spare extruder pieces in black ABS and added them to the 'crash kit' for the printer. You're lucky that you have access to a second printer.
I haven't heard of one of these yet that could not be fixed with the judicious application of heat and reprinted plastic parts. I do remember hearing of a broken thermistor wire, but of course this was due to too much force while it was still encapsulated in the solidified goo.
Dogs are BETTER than Cats
RE: Large Blob Issue (Requiring Hot end disassembly)
I’m by no means an expert, but I’d say if you have access to another printer you should print the replacement hotend parts there.
I’ve just started printing in PETG myself and while it’s an awesome material it can be unforgiving with mistakes.
RE: Large Blob Issue (Requiring Hot end disassembly)
OUCH! That looks like the worst I've ever seen.
Somebody ought to make a gallery of these.
The worst I've had are smaller ones which successfully came off using nozzle heat, gravity and a bit of gentle persuasion.
Soon after I started reading this forum I heard the horror stories of the Blob Of Doom ruining extruder parts, so when the local 'makerspace' closed up due to the pandemic, I printed spare extruder pieces in black ABS and added them to the 'crash kit' for the printer. You're lucky that you have access to a second printer.
I haven't heard of one of these yet that could not be fixed with the judicious application of heat and reprinted plastic parts. I do remember hearing of a broken thermistor wire, but of course this was due to too much force while it was still encapsulated in the solidified goo.
RE: Large Blob Issue (Requiring Hot end disassembly)
@ntdeim
Thanks! Yes I think I should just go ahead and reprint the parts on my dad's printer
Dogs are BETTER than Cats
RE: Large Blob Issue (Requiring Hot end disassembly)
@jsw
Hahah yes someone definitely should make a gallery of this. I myself have never seen a blob this bad either, and usually they're pretty small that pliers would do the trick. I never thought of the extruder parts getting damaged, for I never guessed it would seep up. I think your crash kit Idea is a good Idea and something I'll keep in mind. Sure I have access to my dad's printer next to it, but having already printed parts would ensure a speedy repair. I think I'll reprint the parts, use a heat gun and go gently.
Dogs are BETTER than Cats
RE: Large Blob Issue (Requiring Hot end disassembly)
@jsw
Hahah yes someone definitely should make a gallery of this.
Here you go. I seeded it with some photos that appeared here recently. Everyone, feel free to add to it.
RE: Large Blob Issue (Requiring Hot end disassembly)
Didn't make a mess of the printer so much as a general statement. I think my printer is tired of printing CaliCat.
RE: Large Blob Issue (Requiring Hot end disassembly)
To prevent this in the future(not 100%).
Bed needs to be clean, this is so model will stick. Use dish soap only.
First layer should be 100%, this also helps with sticking.
Then models with small foot print on bed, use a big brim and/or glue stick.
For a big flat model also a big brim and glue stick.
This could help to prevent a blob.
RE: Large Blob Issue (Requiring Hot end disassembly)
If you work with Octoprint, this plugin might give some security: https://plugins.octoprint.org/plugins/thespaghettidetective/
I have never tested it myself, read some positive reports about it, but I don't give any guarantee about its functionality!
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Large Blob Issue (Requiring Hot end disassembly)
To prevent this in the future(not 100%).
Bed needs to be clean, this is so model will stick. Use dish soap only.
First layer should be 100%, this also helps with sticking.
Then models with small foot print on bed, use a big brim and/or glue stick.
For a big flat model also a big brim and glue stick.
This could help to prevent a blob.
To tag onto this- from my experience a properly dialed in first layer is super important with filaments like PETG.
When I first started printing PETG, I had the live z way too far away. This resulted in lots of blobbing and a very unsightly extruded. When I finally dialed in my first lay the blobbing was no longer an issue...
Instead, I now had an adhesion issue. For reference, I’m using the powder coated sheet. What I found was, if the first layer calibration is just a little too low, the filament will get lifted when completing the path of the end of the first layer. So the corner, for instance, will be either just barely holding onto the bed or completely lifted as a result. Depending on the geometry of your print, this can cause no issue, lead to warping, or (in my case) result in the print completely lifting off the print bed and falling over mid print.
RE: Large Blob Issue (Requiring Hot end disassembly)
For those who want to see it, here's the worst one that ever happened to me. I just posted a larger copy of it to the gallery in the link above.
I came back to a print job one day and found the first few layers of my print being dragged around the print bed on a string, like trying to walk a cat on a leash. 😉 It separated from the bed and started to create a Flying Spaghetti Monster and then just blobbed up on the nozzle. Fortunately I caught it before any real damage. This was PLA on the textured sheet.
Heat and gravity with a little gentle persuasion did the trick, fortunately.
RE: Large Blob Issue (Requiring Hot end disassembly)
If the MMU2 is stable, you might get such results with a little luck:
😋
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Large Blob Issue (Requiring Hot end disassembly)
LOL, our cat is a bit shy of the printer when it is going. She will occasionally inspect it, but one thing that drives her away is when circles are printing and it makes those almost musical sounds to trace the arc. I figure there may be some overtones that cats do not like.