I have been brainstorming on potential extruder designs for Morgan, keeping in mind the 3+ material design spec I set myself. To make this work it will have to be a Bowden cable setup of sorts with a material selector in the extruder feed mechanism. To keep down costs only one extruder stepper motor should be used.
Looking at current extruder hot-end designs, and at material cost it is very clear why some new designs are shying away from the use of high temperature insulating materials like PTFE and PEEK, although these designs seems to compromise a bit too much. Clearly we need to find a way to successfully implement some lower cost material that will perform the task of keeping the hot end hot, and the cold end cold, while conserving as much energy as possible in order to remain well within the GADA requirement for power use…
Enter (yet another) another new hot-end.
I am going to use a combination of brass, stainless steel and silicone rubber to do the required. My initial checks and calculations makes this look good on paper. Information on the new hot-end should appear here soon, and follow on Thingiverse. It should enable us to place three to four nozzles in relatively close proximity, while still keeping the weight of the print head down to the minimum and keeping heat where it belongs – in the hot end(s).
Now I just need some time in my lab…