I hope PrusaSlicer 3.x will be seriously more flexible and easier than 2.x for prints using multiple nozzle sizes
So, the Prusa XL has been announced in 2021 and the first machines have been shipped in 2023. Now we're in 2026 and it's still painful to combine layers made with different nozzle sizes in a single print.
What I'm trying to do is to print thin and detailed parts using PETG a 0.1 nozzle. With only this nozzle it functions quite well and I get great results. However as it requires slow speeds it takes ages and the parts are difficult to remove from the bed. So I'm trying to use a 0.4 nozzle to print the first layers.
BUT PrusaSlicer 2.x has some serious limitations which makes it really difficult :
1. If one wants to slice an objects in two big slices as different objects, the upper slice/object cannot lay over the lower slice/object and is put on the bed. So one has to combine a tiny shape to this upper slice in order to be allowed to keep it at an upper position. And it's impossible not to print the tiny part because if you transform it into a negative volume or a modifier the upper slice goes down to the bed again. Of course one can merge the lower slicer and the upper slice. Then the upper slice can lay over the lower one but why impose such a constraint?
2. The first layer of filament can't have differents settings when using a height range modifier even if it is set to start at 0mm.
3. Globally PrusaSlicer isn't flexible enough to comply with the freedom multiple nozzle sizes offer. If one uses settings for a 0.4 nozzle, it's difficult to print the upper slice with a 0.1 nozzle because PrusaSlicer refers itself to "global" settings instead of letting the user totally change the settings when reaching some height in the print.
4. Even if one sets the two slices as two different objects, it's not possible to have totally different settings for the two slices. PrusaSlicer will always refer to the "global" settings and prevent settings it considers incompatible, which makes no sense in such a configuration.
So what I suggest is to allow the user to set totally different settings for each "slice" whenever there is a nozzle change and forget all the limitation imposed by the nozzles used for the lower layers. What's the point in preventing one to make 0.05mm layers because the base settings was set for a 0.4 nozzle although there was a change to a 0.1 nozzle in between? The only thing which should remain constant during the whole print whatever the nozzle changes is the bed temperature.
And if I try to add PLA for supports in the game it becomes even more difficult...
PrusaSlicer has evolved incrementally but sometimes one has the feeling that parts of the software function as if other parts didn't exist. Some changes should have occurred much sooner to take into account all the possibilities offered by multiple toolheads and nozzle sizes — made possible by the introduction of the XL (and now the INDX).