Cold vs. hot toolchange

Hi everyone,

I’m working with some difficult to handle materials and have noticed a curious behavior while attempting to dial in the material parameters. I would love to know if this is somehow related to my setup, or if this behavior can be observed by others as well:

The initial extruder of the first layer in my case is the right extruder. When the printer switches to the left extruder on layer 2, the order of operations is

  1. switch nozzle
  2. heat the new nozzle to target temperature

On all subsequent toolhead changes after the first one, the order of operations is reversed:

  1. heat the new nozzle to target temperature
  2. switch nozzle

This is causing me problems because I am working with very sticky material that sticks to the ooze shield if the nozzle is heated to full printing temperature prior to the swap and causes massive contamination afterwards. I have also inspected the g-code of the filament swap of the various layers very carefully and it is literally identical. As I am beginning to doubt my own sanity, I would love to hear from others if they can observe the same curious behavior on their machines.

Thanks everyone for your help. I greatly appreciate it.