Some 3 mm filaments seem to actually be 3 mm - is there any way to shave off the excess and use it as 2.85 mm?
I would not recommend you to try and somehow re-size the filament, since even the smallest of irregularities and error in diameter occurring from such a process would ruin your prints with sporadic over and under extrusion. Rather, if you have the tools available, you could grind the filament into pellets, and use a filament extruder to make it anew with your desired diameter.
Alternatively, depending on your printer setup, you might very well extrude true 3.00 filament with your 2.85 mm filament printer. If you try to do that, make sure to:
- Adjust filament diameter in your slicer
- Check that your filament isn't getting squashed by the extruder wheel
- Check that all mechanical parts actually can pass through your filament freely
I do not own a 2.85 mm printer myself, and therefore have not tried this procedure. There are, however, several people who seem to have done this successfully.
you could put a 3 mm extruder on you're printer. or (if you're r brave) put route filament in the oven for 10 minutes and unroll it than stretch it out. if you do this outside you can attach one ent to a stride licht or something an pul on the other end, if it is hot anoth it should hold its new position. but don't get it to hot or the filament will stick to itself, you can put talk powder on it to prevent this but be shore to watch it off before using your filament. i have never tried this and not komw is it will work. you can try it on i short pease of about 2 m first to test it oud. if it works, please tell me. i would love to know.