Nozzle temperature change per object  

Assign a different extruder per object.  Define a different filament profile, including temperatures, per object and assign to appropriate extruder.

Cheerio,

RE: Nozzle temperature change per object

Yes that works but is limited by the number of extruders plus you have to use several spools of the same material 🙁

RE: Nozzle temperature change per object

Assigning an extruder per object only makes sense to me when they can be printed in a sequence. That is, for low parts. Or if I do not care about the increased printing duration due to many extruder changes and other disadvantages but really really want to avoid restarting the prints manually. Probably not worth the trouble. Or do I miss something?

Having two different temperatures on the same part makes a lot more sense to me. E.g. for different gloss level, layer adhesion or conductivity with ESD filament.

RE: Nozzle temperature change per object

Typically the way I do temperature towers is by using the slider in the sliced preview. Drag the slider to where I want the temperature change. Right-click on the slider and select "Add Custom G-code". Enter in the extruder temperature g-code without wait, "M104 <target temperature>". Typically I start with the highest temperature of the tower on the bottom, lowering heat as I go up. If you use "M109 <target temperature>" then the print will pause while the temperature changes (at least it will when going up in temperature, I forget if it will when going down in temperature), but this is often unnecessary when going down by 5°C-10°C as it will only take a layer or two of the solid/cold filament going into the nozzle to help cool it down. My temperature towers are often stepping down by 5°C per section.

Granted, I'm only printing one tower at a time. But if you are doing multiple towers and have the sequential printing turned on this should still work as long as you don't get any collisions with previous printed objects... 😉

If you really want to use the multiple extruder method, make sure the tool-change gcode is empty (it should be if you simply increase the extruder count in the printer profile) so you don't actually trigger any filament changes at the printer. This is how I had to do it for changing retraction distance when I was printing multiple retraction test objects to tune for lowering stringing.