

I have been printing more than a decade and have not seen this. But I suspect a clog? Then the filament burns inside and eventually comes out all chared? Or temperature control issues where you nozzle gets way too hot for short times? Just guessing here …
Edit: did some searching:
Burn marks on 3D prints usually appear as black or brown specks, streaks, or burnt blobs. They are primarily caused by melted plastic accumulating on the outside of the nozzle, gaps in your hotend causing filament to leak and cook, or a printing temperature that is simply too high.1. Clean the Outside of Your NozzleOften, small amounts of plastic cling to the hotend during printing. Over time, this filament cooks, oxidizes, and drops off onto your print.How to fix: Heat up your hotend to your printing temperature and carefully scrub the exterior of the nozzle and heat block with a small, brass wire brush.
Clean the Outside of Your NozzleOften, small amounts of plastic cling to the hotend during printing. Over time, this filament cooks, oxidizes, and drops off onto your print.How to fix: Heat up your hotend to your printing temperature and carefully scrub the exterior of the nozzle and heat block with a small, brass wire brush.
Check for Hotend Leaks (Loose Nozzle)If melted plastic is seeping out from the threads above the nozzle, it will slowly burn and periodically drip into your model.How to fix: Heat the hotend to at least 250°C. Hold the heater block with an adjustable wrench, and use a socket wrench to tighten the nozzle firmly. The goal is to make sure the nozzle sits completely flush against the heatbreak (or the PTFE tube on non-all-metal hotends).
Lower Your Printing Temperature
Remove Internal OxidizationIf you’ve recently switched from a dark-colored filament to a light-colored one (like white), residual burnt plastic from the dark filament can linger inside and randomly appear.How to fix: Manually extrude 10-20 cm of the new light filament through the hotend at a slightly higher temperature to push out all the old, oxidized residue.


Why not print “back side down”? So you need specific line orientation?
Ok I just downloaded…now I need to learn what it is.


Totally fake ! What newspaper is that narrow!?!


Portable case for my mavic mini, more compact than the original carrying case, gridfinity organizer for my drawers… can fit s lot more stuff and super organized, stands, racks for my mechanical puzzle collection, protectors for my FPV drone camera and arms, tons of accessories for FPV controller, fixed a broken camping chair by cloning the plastic feet that joins the rods of one leg. Broken adapter for my vacuum cleaner, broken battery case for my electroacoustic guitar, and …well the list goes on and on…
Nah…made a call…what’s the best I could…i moved on … what shitty like aprosch just worrying about things from the past and not letting go.
I have owned 6 different printers over several years. Nothing comes close to bambu nowadays. It’s the closest to a consumer product currently. A1 is a great workhorse and worth the slightly above 500. Id the mini has enough built volume then that one. If you want to tinker with the printer a bit then go with some of the alternatives mentioned here.
I don’t get it… An idiot? A pro slavery? A looser?