Multiple Extruders - doesnt seem to work properly? Is this a bug?
Basically two Extruders (0.4 and 0.8mm) set up as 1 and 2 in Printer Settings tab. Each has custom settings as they are different sizes.
In Print Settings tab I set each item in "Multiple Extruders" to "2" (as in Extruder 2). The expectation is of course the Slicer will use the settings assigned to "Extruder 2" in the Printer Settings tab for slicing. It does not with two different issues occuring:
The first (more minor) quirk is: PrusaSlicer uses "Default" extruder in the Plater tab. Logic would suggest that would be (in this case as specified in Print Settings) Extruder 2.. however it just uses Extruder 1 anyhow (well, uses Tool 2 but settings from Tool 1, which is bizarre) unless Default is changed to explicitly specify Extruder 2. Why is there two areas to specify Extruder to use.. whats the point in the Multiple Extruder setting if its completely over ridden in the Plater tab?
The second problem, which is worse, is that the Variable Layer Height Adjust feature always uses Extruder 1 settings, no matter whats selected in either the Print Settings or Plater tabs! This leads to selecting entirely incompatible layer heights (and presumably everything else in the Multiple Extruder tab) and introduces the " Invalid spacing supplied to Flow::with_spaceing() " error message, which is how I traced back where this issue is starting.
RE: Multiple Extruders - doesnt seem to work properly? Is this a bug?
Prusa Slicer doesn't really support different nozzle sizes like that as yet. Not properly anyway. There are several issues over on the PS github relating, such as https://github.com/prusa3d/PrusaSlicer/issues/393 or https://github.com/prusa3d/PrusaSlicer/issues/7045 for example. I'm sure there are others too.
Not surprising as the current multi material Prusa offering is the MMU which is only single extruder, that all the software changes have gone to support that.
As for the print settings, well just because one user expects something to work one way doesn't make it so. Get used to using the software as is or find a slicer that suits your expectations and workflow better. Change requests can be made at the github project but given that there are currently over 2000 open issues don't hold your breath waiting. There are issues that have been open years.
Given that different nozzle sizes on different extruders is one of the things users want the most on the upcoming XL printer then I suspect that will change. Prusa have acknowledged in various posts/comments/tweets etc that support for that is lacking and if they really want to take advantage of the multi extruder capabilities of the XL then its pretty much a given that PS will have to be updated. So I'd expect that side of things to have a higher priority. What priority is given to what is a fun guessing game as no one external to Prusa has any clue. You have to pick up hints wherever you can from social media and comments on issues.
Doesn't help you much now I know.
RE: Multiple Extruders - doesnt seem to work properly? Is this a bug?
All good, really just wanted to confirm I wasnt going crazy as it seems so obviously not quite right!
RE: Multiple Extruders - doesnt seem to work properly? Is this a bug?
Thanks for sharing your thoughts everyone. Much appreciated. Apparently, multi-extruder setups with different nozzle sizes is a topic not many people care about - understandably.
Came across the second problem too. Not only Layer Height is an issue here, but also Horizontal/Vertical Shells, Extrusion width (I set it to 0 for the time being), Speed for print moves to name the most important ones. To keep the GUI simple for the more common single-extruder case, I would in case of multiple extruders, create a separate tab for each extruder that allows you to select the filament and the properties mentioned above on a per-extruder basis. Sounds easy, but most certainly entails a whole rewrite of the slicer.
Anyway, I hope Prusa will up their game when they ship their Prusa XL model, as it otherwise is pretty much overkill hardware that lacks support from slicing software. I would be willing to pay 50 bucks to use a PrusaSlicer Pro Version for XL.