I repeatedly criticised that the hotend of the Ax50 contains a PTFE liner while being rated 275°C. However, I usually put in a “but”: If the PTFE liner only protrudes into regions that never get hotter than 240°C, there´s actually no problem. Now watching Thomas Sanladerer´s review of the Prusa Mini (https://www.youtube.com/watch?v=Ce4oluQxyc0), I learn that they follow exactly that concept: a PTFE liner that keeps cold enough even when printing at 275°C. Since I yet did not go as high in temperature, I´d like to hear if anyone did, and if anyone can share his or her experiences with the degradation of the PTFE liner. Only one facebook user yet explained that he replaced the liner after I think it was 500 hours of printing or so. But one is bad statistics…
I don’t use facebook, did he say he was printing at 275 for 500 hours? Or just after 500 hours of printing. As far as the PTFE liner, I would imagine it could last for a long time if done properly. I am concerned however by how hot some people have described their 3d tool heads have gotten and the default of 5mm retraction(what made SM think there was that much pressure?). In my mind the tubing would be fairly easily damaged if trying to print high temp material. I’m thinking of what could happen if material above 230 (I know you said 240 but the only ptfe I know capable of that temp is Capricorn XS, and the liner is not that) gets pulled up into the ptfe tube (say during a filament change) i would love to hear from staff why a ptfe liner was used over an all metal hot end? Was it purely cost motivated?