I have a daily habit of working on side projects, and I've come to appreciate the benefits of tracking that habit out in the open. If I'm doing work on a software project, I track that on GitHub. If it's more hands-on, I like to post an update here.
I switched back to the 0.4mm nozzle on Friday. Printer is still working flawlessly. The calibration cube pictured above is certainly the best I've seen in weeks.
I think the problems were caused by two separate partial clogs: First after a change from Prusament PLA to Fillamentum NonOilen, the second after I ran the Mini's built-in first-layer calibration (which assumes a 0.4mm nozzle) with the 0.25mm nozzle.
This is hard to believe, but I managed to print something without any issues, for the first time in weeks. And not only once, I did two of these first layer calibration prints in a row, plus a spacer.
Before that, I was cleaning the nozzle on the outside and figured, why not heat it way up, to see if that can get any potential obstructions out of there. After that and a filament purge, I've only seen good prints so far.
Could it be that all of these mystery problems were caused by partial clogging of the nozzle or hot end?
The trend continues. Every attempted solution to a problem creates new ones. Now I'm having issues with z-axis calibration. It's out of calibration, I adjust over a few prints, now everything's great. Then, for next day's first print, it's out of calibration again.
I figured that maybe, due to the new improvised enclosure, the printer heats up over a few prints, causing the z-axis to expand. And in fact, some calculation based on plausible guesstimates tells me the aluminium extrusion that holds the z-axis might grow by 0.13mm. That's more than half the first layer height, and about the same as my adjustment to the z-offset value.
But of course, if the z-axis grows, the z-position should be too low for the first print, which is the exact opposite of what I'm seeing. After many weeks of this kind of stuff, I'm so thoroughly confused.
My new 3D printer enclosure. I can assure you, I will start designing a new new one shortly. But in the meantime, let's see how this one works out.
The splurging of plastic from the printer keeps happening. I'm pretty sure my theory about excess material in the nozzle was bullshit. I'm now thinking that the problem could be temperature-related.
There's a lot of plastic coming out in a short time, and its consistency is different from any extruded PLA I've ever seen. I don't think this could be happening at normal temperatures, so maybe there's a problem with the thermistor, or a temperature gradient between thermistor and nozzle caused by environmental factors.
I'll try to find a fitting cardboard box to improvise an enclosure to see if that helps. If not, I'll have to look into the thermistor.
