K2 Waste chute blockages; could machine level be an issue?

Flagship K Series
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Just lost a nice two-colour lithophane to a waste chute blockage. Or at least when I checked the machine, which actually said the filament was blocked between the extruder and the AMS, the waste box was full to overflowing and in fact the printer seemed to have lost both its sense of position and dignity and had started pooping directly onto the print bed.

There was indeed an extruder clog, but very small - I think the waste chute had filled, so the nozzle was in contact with “old waste” from previous colour changes. I think this had caused it to |“back up” and thus cause the extruder clog.

I’ve got my own design waste chute on my machine and thought that might be the problem; but it was totally clear, whereas the waste “box” (for want of better word) on the K2 was chock-a-block with little spiral turds.

Are we any closer to getting some idea why this happens and more importantly how to stop it? It makes the idea of leaving a print to run for more than a few hours laughable (this happened after just four hours).

I’ve one topic for discussion - my printer is not on a level surface. I know this is less than ideal, but it’s hard for me to correct, so my printer currently leans forward by maybe a degree or two, no more. This of course means the slope on the waste chute is reduced by the same amount, but also, a “poop” from the nozzle is a fraction closer to the front of the waste box than it would be if it were vertical.

Could it really be that sensitive? I don’t know, so I’m asking for data; please reply with answers to the following;

  1. Do you find your waste chute gets blocked?
  2. Is your printer;

a. vertical/level
b. leaning forward slightly
c. leaning backwards slightly

I’m thinking the hitting the front of the waste box issues is more likely a cause of the problem than the reduction in slop of the outlet by a degree or so…but either way I thought it was worth checking.

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This. This is what I’m talking about…not even thirty seconds into the print and already an uncleared turd in the box…

PXL_20250316_203340850
PXL_20250316_2033408501920×1446 179 KB

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Think something might actually be broken now…it seems to be making no attempt to clear the waste at all…I seem to remember that before the bad overflow there was an arm of some sort that at least made some sort of attempt to “scoop the poop”. Now, nothing. I’m wondering if the army of unscooped solidified poop may have broken it. :-(.

Does anyone know if a spare is available and how big of a job it is to repair if so?

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I just dismantled the bezel and head cleaner. This is not a job for the faint of heart nor fat of finger.

The split pin that holds the bezel in place is…small. Tiny. Miniscule. Microscopic. I’ve seen insects with bigger legs, and they were fairly small insects. The split pin is also blessed with The Power of Ping.

I saw a split pin fly through the air, it came to earth I know not where…

So, 42,000 years later when I found it (under the printer - how it managed NOT to be on the floor I have no idea) I took off the bezel and the nozzle scraper.

Now, I noticed the “handle” on my bezel was kinked over, and the scraper, shown in Creality’s video as a true 90 degree angled piece was - well it depended which prong you look at! The back one was depressed to at least 80 degrees, the front one more like 88-ish. This difference had caused quite a lot of torsion on the actual scraping blade.

So I removed it (tiny, tiny allen screws this time, and my Parkinsons’ medication wearing off.,…) battered it flat with Extreme Prejudice (yes capitals intended; if Thor can name his hammer, I can name mine) and put everything back together…this time remembering to tape off the chute (note to self, design screw-catcher box for future maintenance work).

The bezel moves far more freely now, but I won’t have chance to see if I’ve made things better (or worse) until tomorrow.

PS: I’ve no idea how the bezel works…it’s on a smooth round rod and I can’t see any mechanism that would lift it up - magnet?

Anyway wish me luck…for tomorrow. I’m going to bed.

Creality’s official line on how to do this…oh as an aside my split pin was in BACKWARDS compared to the video…I’ve no idea how they managed to insert it from that side!

1 Like
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Hello GreyArea,

I love reading your posts, they are MOST entertaining.

Cheers.

1 Like
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I hope to inform, if I entertain as well then I’m glad I made you smile.

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Talking of informing, I’ve figured out how the bezel works…the print head batters it; that’s what the little upstand “handle” is for on the bezel, so it’s entirely physical. But it has to be said, the tolerance is tight and mine was bent outta shape even before Attack of the Mega-Poop so I’m not sure the head would have hit it, and at best was probably not moving it as effectively as it should.

Might be worth checking if you’re getting regular blockages.

Rather than add another post;

This is how it works;

When the head moves back to over the waste port, It hits the lever that lifts the bezel. It does it’s purge onto the raised bezel (so the fact I could see mine clearly purging directly onto the clear acrylic waste cute was a certain sign that something was wrong).

The nozzle then moves left and right a few times to shake the bezel up and down, to (hopefully) deposit the poop in the chute.

So I’m thinking; bigger purge volumes = bigger poop = more chance of blocking? I don’t know how much filament the extruder can drop onto the bezel before it backs up to the nozzle, but when I’m (trying) to go from red to white, the purge volume is listed as 893 (for comparison black to white is 965).

I doubt that’s millimetres of filament but it’s still a big number…I wonder if there’s a way to lower the bezel somehow?