Specialty Filaments
After struggling to get large parts to print warp-free with PLA or ABS, I decided to give some carbon fiber filaments a try. I didn’t spend a whole lot of time picking a filament, but I eventually landed on Polymaker PET-CF17. As the name suggests, it’s PET with 17% chopped carbon fiber. Long story short, I love this stuff, but there was a learning curve - and some frustration - getting it working properly in my Prusa CORE One. I could have avoided some of these problems with a little proper planning, but that’s not how we do things here.
First off, the stuff is abrasive and needs a hardened nozzle. I decided to just get the ObXidian version of the nozzle I was already using - a high-flow 0.4 mm version. That was a mistake. It didn’t take long to clog in a way I couldn’t fix, so I wised up and got a regular 0.4 mm nozzle. Also a mistake. I printed half a spool with it before it clogged, resulting in a blob of death that took the nozzle, fan shroud, thermistor, and heating element down with it. At this point, I decided it would be wise to seek help and found that Polymaker suggested using a regular (non-high-flow) 0.6 mm hardened nozzle. That is what I have now.
After figuring out that this filament really needs to be dry, it all came together. This stuff is incredible. There’s no warping to speak of, and dimensional accuracy is very good. If it wasn’t so expensive, I’d use it for everything. Highly recommended.
Speaking of specialty filaments, I’m also a huge fan of ColorFabb Varioshore TPU. It’s TPU, but it contains some sort of foaming substance that foams up as the nozzle temperature rises. At low temperatures, it’s just like regular TPU, but gradually, as you raise the nozzle temperature, it gets more and more spongy. I would recommend going through some test prints to iron out the required settings (CNC Kitchen has a good guide), but once you’ve done that, it prints very well.
