Can nozzle temp change for filament swaps be moved in PrusaSlicer? Or maybe it is a needed feature?  

Can nozzle temp change for filament swaps be moved in PrusaSlicer? Or maybe it is a needed feature?

Just got my MMU2s installed and running.

It actually runs very well, despite the horror stories. I think how the new S version changed filament detection at the extruder solved a LOT of issues. Overall, it just does its thing very well.

However,

The one issues I have is stringing on retraction, and particularly when using different materials, though this would help when you are using the same material as well.

Here is the current work flow for my PETG/BVOH changes:

Running PETG @245c, it complete what it needs to do and goes for a tool change to BVOH.

As soon as it starts the travel move to the tower, it calls for a new nozzle temp of 215c. Nozzle temps starts falling right away. For PETG, this is GREAT as the cooler nozzle temp means it unloads reliably with nearly zero issues.

After it swaps to BVOH and runs the BVOH all it needs, it calls for a tool change back to PETG. Here comes the issue:

Again, as soon as it starts the travel move to the purging block, it increases the temp up to 245c. This is 25c above max for this filament, and causes massive stringing issues. I've tried to sort it out as best as I can with settings in Prusa Slicer, and it works mostly, but some simple software changes would dramatically help here.

1. Add an "unload temperature" to the filament profile. This should probably be an M109 at the purge block, after a bit of normal retraction. It could park the nozzle just outside the perimeters of the purge block to deal with any stringing. Once the "unload temperature" is reached, continue with the unload. After filament is unloaded, another M109 with the temp of the new filament. After temp is reached, continue as normal. 

The addition to the smallest amount of code would dramatically help with both mutli-color (same material) and true multi-material  printing.

OR

PLEASE, PLEASE, PLEASE tell me there is already a fix for this that I missed 😀 

Oh, I also had to replace the PTFE tube between the MMU and the extruder to deal with the very stiff BVOH filament, as it was binding on the tight-ish curve that was present with the OEM length of tube. Another very simple fix for Prusa.