What i need to buy/upgrade to print over 300°C?
Just placed an order for a MK3S and i about to order stuff from E3D (nozzles so i can print fiber reinforced materials and different resolutions/speeds), silicone socks, PC and Nylon filaments (since Prusa store didn't have those), but i am also looking to try high performance plastics like PEEK/PSU/PEI which need 350-400°C temps. What upgrades/ do i need to buy and what other changes are needed to do this?
I am assuming this is needed as a minimum? https://e3d-online.com/v6-pt100-sensor-kit
Does the MK3S board have an extra analog input?
Kind regards
Note: It's my 1st 3D printer but i'm a mechanical engineer with some 3D printing experience and quite knowledgeable in electronics as well.
Re: What i need to buy/upgrade to print over 300°C?
You will probably need to compile your own firmware, unless you can find someone who's already done it. But the firmware for the MK3S is so new that likely you are the pioneer in this. You can certainly start with Prusa's version of Marlin (in fact, you must if you want to take advantage of things like the PINDA probe and the filament sensor), but you can change Configuration.h and/or Temperature.h to indicate that you're using a Pt sensor instead of a thermocouple. I'm not completely sure, but I think there's a good chance then that the analog input currently used for the thermistor can become the analog input for your platinum probe. There may be a few tricks involved, because the thermistor circuit uses commands in firmware to introduce a series 4.7k resistor to +5V to "excite" the thermocouple circuit; this 4.7k pullup may or may not be correct or interfere with the way the Pt probe works.
You will also need to get an E3D V6 "all metal" hot end which is designed for these ultra-high temperatures. I believe the PTFE tube on the Prusa version of the E3D gets dangerously close to the hot zone, and PTFE melts at 327C.