K2 owner here for 18 days and CR10sPro owner for 4 years. Zero problems setting up and running the K2 (mainly using PLA without glue) so far but yesterday had a massive blob the likes of which I have never seen before while printing regular PLA . There was a error message on the screen but it was still spewing out filament when I came back 50 minutes later to check, to find the print failed to adhere to the bed and it looked like this.
I had to partially dismantle the head but fearful of over heating fan housings connectors, circuit boards etc I decide not to apply heat to the blob with a hot air gun instead I heated a box cutter knife blade and slowly hacked away enough of the blob to remove the hot end.
All up this took about 2.5 hours.
Next I tried to remove the nozzle (somewhat foolishly without heating the holder) and snapped off the tip. I’ve removed nozzles on the CR10 when used with PLA before without heating but did not realize the copper nozzle would be so soft.
Anyway I managed to get the threaded section out easily (almost by hand) by applying heat with the SMD heater and using a 3mm easy-out left handed screw remover.
A small but useful benefit is I now know how to remove and replace the hot end and even tackling such a mongrel of a blob. I’m now concerned if it was to be a higher temp plastic although these seem adhere better to the PEI plate than PLA. Am now using it with glue.
I have to admit I was surprised the K2 let things get this far. Just wondering if anyone else has seen a K2 with such a massive blob?
It looks like at least on the current firmware versions, and possibly only on some printers, the AI detection feature simply is not working. Have no further details on this unfortunately. Mine will try to put down flow calibration lines, ball half of them, scan it, then somehow decide the flow should be 0.95 from that. (Then fail putting down the first layer and not stop for that either.) Must baby-sit the first three layers until this all gets sorted out.
Fully sympathies!!! Hot air gun and a box cutter are your friends. The best type of hot air gun is one you can stand on its back side. Heat the box cutter blade in the hot air stream and slowly cut away at the blob until you can remove the whole hot end from the head. You may just have to ditch the fan and buy a new one
If you have, or have a friend, or a makerspace with a hot-air electronics “reflow” soldering iron, these work great for removing filament blobs. Something like the prolific 858D is ideal and inexpensive, and often sports a max power output of 800W, which is impressive considering its size and price. Use the largest tip, and set the temperature to slightly over the filament melting temperature. Work areas slowly; remove chunks gently with tweezers. Stainless steel tweezers are ideal as SS conducts heat poorly so keeps your fingers cooler. With some patience, can remove most of the blob, then remove the hot-end (while everything is still hot) to get the rest. It is possible to remove filament from fan blades, but depending on the fan plastic, it could be damaged from the heat. Glass-reinforced nylon fans are common, and that material’s glass-transition temperature (what temp it softens at) may be very close to your filament temperature.
and even tackling such a mongrel of a blob. I’m now concerned if it was to be a higher temp plastic although these seem adhere better to the PEI plate than PLA. Am now using it with glue.