Temperature to switch nozzle tips?
On my other printers, I have E3D and MicroSwiss all metal hotends where you need to heat the hot-end to about 250℃ to get the nozzle tip to seat correctly against the heatbreak when tightening it in.
Should I do similarly with the CR-6 SE or does the PTFE lining make that irrelevant?
The most relevant video I could find https://youtu.be/98O0S9MqQ58?t=180 shows assembling a complete nozzle assembly cold, out of the machine. The only detail I noted is that the heatbreak is inserted before the tip is tightened.
Is it acceptable, then, to change nozzle tips on a cold, unplugged machine? Just remove off the silicone sock, grip the heater block so you don't damage the heat break, unscrew the current tip, screw in the desired tip, put the sock back on and you're good to go?
I don't mind doing it hot... just would like to know what's best for this hot-end. (Looks like 21mm wrench/spanner to hold the hot heater block, but would probably have to grind down one side to avoid taking off the fan every time.)
No. heat the nozzle to 225-235. You will destroy the threads in the block otherwise.
Wound up answering my own question by trying it. I wasn't able to budge the tip when cold, probably because of residual filament gluing it in to the hot end. So, hot it is.
Two challenges in this process:
- The provided nut driver is deeper than the tip is long, so you have to hold the nozzle tip with something else (like your fingers ) to start it threading in to the heater block
- a metal crescent wrench holding on to the heater block conducted away enough heat to trigger a thermal runaway shutdown.
Fixes for these do come to mind... I might try milling a wrench out of wood and gluing a nut in the bottom of the driver to take up some of the depth.