"All Metal" mk3 hot end maximum temperature

A few months ago Tiertime sent me a replacement extruder for my Cetus which seems to be the mk3 steel nozzle version. I though this version was an “All Metal” hot end, however, looking inside the stainless steel cold end I see a white sleeve liner. Unfortunately I can’t tell if the liner is plastic or ceramic without risking destroying the thin walled material.

Does anyone know the maximum temperature of the “All Metal” mk3 hot end?


I was emailed by Tiertime via ebay that the maximum filament extrusion temperature is 300C.

The bad news is that heat is a problem. I measured 15.3V rms across the heater (FYI 9 ohm resistance) while extruding PLA at 224C with the cooling fan on. During the initial warm up the voltage across the heater was 18.4V. What these numbers say to me is that 18.4V the nozzle might eventually get you to 265C but after a very long warm up time. So for ABS it is just hot enough with reduced fan cooling while polycarbonate needs 270 to 290C so probably not unless some modifications are done.