Change nextruder nozzle while it's hot?
Hi!
One of the biggest annoyances I've got with the MK4 is waiting for the nozzle to cooldown (after I've unloaded the filament) so I can unscrew it and replace it with another sized nozzle.
I just assumed that it's not wise to change nozzles while they're hot but... is it? Am I risking damaging anything (aside from burning myself) when changing nozzles while they're hot?
RE: Change nextruder nozzle while it's hot?
Depends on how you do it. If you follow the Prusa method of disconnecting cables etc, I wouldn't do it when it's hot. And you can't use that popular unscrewing rig either. But if you hold the hotend with pliers and use a wrench to unscrew the nozzle, yeah, I've done that.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Change nextruder nozzle while it's hot?
After unloading, I usually let it cool down a bit, to get the most heat out of it (so it doesn't make burn marks in my table). After that, I unscrew the bottom thumbscrew, unplug the connectors, carefully take the hotend assembly with pliers right above the heat block, and unscrew the top thumbscrew, and get it out. Just make sure that you're used to the different steps (practice with a cold assembly), so you can do it quickly and without burning yourself.
I always make the changes on a hot assembly, since it just take too long to cool down again.
Another option would be to always unload after you finish your print so it's always possible to swap the nozzle. I don't do that because I like to have the printer ready to go so I can start a print without having to go to the printer.