Hi all,
This happened to my son’s Ender 3 v3 KE last night. Anything we can do to save it? The printer is only 100 days old 
I can see some wires encased in the blobs.
And why does it look like it overflowed from the top of the rubber boot thingy?
Thanks
Good news! Creality is going to send me a new hot end assembly.
Can anyone tell me what would have caused this? I’ll probably get a better understanding when the new parts arrive, but I just can’t understand how it appears to be overflowing from the top down.
I’ve had that happen to me at least once on my original ender 3. Basically, it’s caused by the nozzle/heat block/heat break assembly not all being tightened together sufficiently. It’s often possible to salvage some of the hardware from that sort of mishap. There’s a very high chance that the thermistor, and probably the heater cartridge as well.
So maybe the nozzle gets plugged and it just forces its way out any opening that’s there already or any interface with a weak enough seal? If you look at the picture with the level sensor on the left, to me it looks like the print got all bunched up around the nozzle (you can see strands), then the blobs came down from the top on top of it.
Thanks!
Hotend nozzles operate with a fair amount of pressure. Might depend a bit on your extruder, but I would say as a rule, that if your nozzle clogs, the extruder should be the weak link, and start skipping. If I had a blob like that every time a clogged nozzle happened, I’d have bought a lot of hotends by now. It could be though that your hotend was just barely holding the pressure in, and then the nozzle clogging was the final straw, but it shouldn’t be that way.
My guess is that the nozzle was not tightened properly, then clogged, and the filament came out around the base of the nozzle and filled the cover and overflowed…
Bob
Basically the jist of it is you had a leak. You likely had other symptoms for a while but went undetected. Good news is nothing is likely broken. i’m not familiar with the latest parts of the ender 3 … I’ve switched to micro swiss a while ago. It a pain but if you disassemble everything and have the tools you need, heat gun … you can recover the hot end.
Either a leak in the nozzle, heat break … somewhere in your hot end.
Just to put an ending on this. I got the replacement hot end parts after two or three weeks. I swapped it all out. Printed a bency then something else and caught a whiff of burning plastic. Pulled the silicone boot off and found that the new parts leaked too, but I caught it before it spilled out of the boot. I heated it up again without the boot, to get all the plastic to melt off. Once that finished, I cleaned it up to remove all traces of filament. Then I tightened the nozzle while it was hot. Been running fine ever since!
Thanks for your pointers everyone!
Aha, not tightening the tip when it is hot. Rookie mistake.
The tip came preinstalled, so manufacturer mistake? 
You should always still hot tighten the hotend when you get it from a manufacturer. Metal changes shape when it heats up which is why you need to heat-tighten it. The manufacturer will not heat tighten these at the factory as they are just assembling it together!
Good learning experience, never assume it is tight enough, always check it for yourself.
Ah grasshopper, one must always double check. Remember Confucius say “manufacturers quality control ain’t worth $#!+”.
Truly words of wisdom.
In the words of another wise man:
Fool me once … shame on … shame on you…
You fooled me. Can’t get fooled again.
Same thing happen ed on both my KEs. I may have to buy a couple hotends to have on stock. Both printers are under warranty but not covered.
A bit of a followup to my original post. We used our printer for maybe 200 hours after installing and hot tightening the new nozzle. Then it exploded again. Luckily, I was able to cook it off and clean it up. So I guess I need to add hot tightening to my periodic maintenance…
Yes adding heat tightening to you maintenance schedule. Basically every time I go to clean or repair something on the printer I will also do a hot tighten on the hotend!
