My Weekend Battle with a Stubborn Prusa Mini

So my Prusa Mini had been gathering dust for a few weeks when I finally needed it to print a case for my new Raspberry Pi 5. Loaded up some pretty yellow silk PLA (you know, the shiny stuff that looks gorgeous when it works right), sliced the file, and hit print.

I always hover over the first layer like an anxious parent - and thank goodness I did, because wow, what a mess. The filament was going down in sad little blobs, with some spots getting nothing at all. Not exactly the solid foundation you want for a functional print!

After the usual string of mild curses, I tried again… same result. Checked all the obvious stuff: bed leveling? Fine. Surface clean? Spotless. Z offset? Exactly where it should be. Then I pulled out the filament and spotted it - little bits of debris clinging to the end. Great, extruder issues - every 3D printer owner’s favorite problem (not).

Into the Extruder We Go

If you haven’t had the pleasure of dealing with extruder problems, here’s the deal: this little mechanism has one job - push filament through the hot nozzle at precisely the right speed. When it gets gunked up, it’s like trying to push Play-Doh through a straw with a chopstick that’s covered in glue… not efficient.

Looking at my debris-covered filament, it was pretty obvious why my prints were failing. The extruder was struggling to push the right amount of plastic through, leading to those sad, patchy first layers.

I could write out the whole cleaning process, but honestly, Prusa’s documentation¹ is ridiculously good (which, let’s be honest, is half the reason I paid extra for a Prusa instead of going with a cheaper printer). Their step-by-step guide is basically “3D Printer Maintenance for Dummies” - perfect for me after my second cup of coffee on a Sunday morning.

Nozzle Drama

With the extruder looking good, I moved on to the nozzle. The standard test is just pushing some filament through and watching how it falls - it should drop straight down like a tiny plastic waterfall, not curl back up toward the nozzle like it’s having second thoughts.

My first test looked… okay? Not perfect, but not obviously terrible. But “okay” isn’t good enough when you’re already elbow-deep in printer maintenance, so I went for the full cold-pull² treatment. For the uninitiated, this is where you basically use the filament itself as a pipe cleaner to yank out any gunk inside the nozzle.

Sure enough, when I pulled the filament back out, I could see tiny specks of debris. Nothing major, but enough to mess with those precise extrusion tolerances that make the difference between a beautiful print and a plastic spaghetti monster.

The Homestretch

Since I’d already gone this far, figured I might as well give the whole machine a once-over. Tightened a few screws that had vibrated loose, wiped down the rails, and made sure everything was properly squared³ and tensioned⁴.

Then came the moment of truth - recalibrating that Z offset for what felt like the hundredth time (seriously, why does every little adjustment mean redoing this?).

Loaded up that same yellow silk PLA, crossed my fingers, and hit print again. And… perfect! That first layer went down like butter on hot toast. Smooth, even, and sticking exactly where it should.

Moral of the story? Even good printers throw tantrums if they sit unused too long, and a little preventative maintenance goes a long way. Also, silk PLA might look pretty, but it’s definitely pickier about clean nozzles than the standard stuff!