My mk3's extruder was engulfed in a solid blob of plastic
Ugh. I left a 4 hr print to do its thing. Shortly after it started, something must have scraped free or lifted or something and it blocked the nozzle and re-directed the entire print's worth of plastic up into my extruder, engulfing it in a golf ball-sized blob of solid Prusa-orange PET.
I have seen this before, so I know I am not the first, but man, what a bummer. This will be my first disassembly of the printer. I dont know what all will need to be replaced, but it is definitely everything below the two fans, and probably the heater assembly.
That's what I get for running it un-attended I guess.
Re: My mk3's extruder was engulfed in a solid blob of plastic
Re: My mk3's extruder was engulfed in a solid blob of plastic
It's often not as bad as it looks. You can heat up the extruder and gently pull the plastic away once it softens. Careful use of a heat gun on the outside can also help.
Here's a picture of mine when it happened. Luckily mine was PLA, so it took less heat, but I was able to remove it without any damage to the printer.
Re: My mk3's extruder was engulfed in a solid blob of plastic
We have seen this before. The recipe is a clean bed and a correct Z level.
Wash the steel plate with detergent and water, wipe with paper. Then, do not touch the bed with your fingers.
Bear MK3 with Bondtech extruder
Re: My mk3's extruder was engulfed in a solid blob of plastic
Does it inevitably first happen on layer 1? That's what I'm assuming. I had the blob of doom once, and since then I don't walk away for long until after layer 1 is done.
Re: My mk3's extruder was engulfed in a solid blob of plastic
Does it inevitably first happen on layer 1? That's what I'm assuming. I had the blob of doom once, and since then I don't walk away for long until after layer 1 is done.
No. Mine was well into the print when it happened. I do agree with RHDreambox in that keeping the bed clean is key to avoiding it. I had been lazy about cleaning prior to this fail.
Re: My mk3's extruder was engulfed in a solid blob of plastic
Thanks for the hints. I will certainly try to salvge any parts I can. Some of my factory black PET pieces look like they may have melted along with the blob, but I will stay hopeful!
Re: My mk3's extruder was engulfed in a solid blob of plastic
As a follow up, I was able to pre-heat the PET blob using the ABS pre-heat setting, and then carefully pry it off of the extruder assembly. First I was able to carefully pull out the fan shroud which was thankfully not damaged. The blob came off in mostly one piece by getting a small screwdriver into it and tugging on it steadily. It pulled off as the heated softened plastic let it stretch away. I then picked at remaining smaller chunks of plastic still wedged around the assembly. Got a lot of it, but could not get all. I will likely do a full tear down and re-build once I print the new updated extruder parts, as well as the replacements for the slightly damaged extruder assembly parts.
It is printing a PLA part right now, and other than having to re-calibrate, it seems to be running fine.....I likely wont leave it alone again until several layers are good and soundly created. The failed part looks as thought it messed up shortly in to the first layer and went down hill from there.]]
Thanks for the suggetion to pry it off! I dont think I would have even tried to do that given how bad it looked!