After discussion about setting the standby temperature for the idle toolheads, the thing I want to do is pre-heat them 'just in time'. Is anyone aware of any slicers, post-slicing tools, or an OctoPrint plugin to add in heating commands in advance of the tool changes, so each tool should be hot when needed, but doesn't need to be kept hot all of the time? (I.e., minimum time wasted waiting for a heat, while minimum wasted energy and dribble by allowing the heads to cool when not needed.) (I realize any pre-computation of this will be an estimate and not perfectly accurate -- only an OctoPrint plugin would be in a position to actually monitor the print progress and make more accurate guesses.) Unfortunately it looks like Simplify3D doesn't embed time estimates, so this isn't just a trivial script.
I read recently that Cura was doing something for this, not sure if that is just for dual extrusion or general multiple extrusion though.
I have been thinking about the applicability of this and got to think about the filament and how continuous heating and cooling (this is how you would temper metal) would do to it and the risk of clogs due to this, is keeping the filament under Tg temperature better in this case, and how should we treat fast tool changes like at what point is it OK to keep the tool hot waiting for the next tool change, right now what i do is if I have a long time between tool changes (>5min) I will keep the tool off and heat it when it is picked up it takes 2 min to heat up in long prints that is not a huge addition to the time of print but if it is less I keep it hot and hope the brush cleans the oooozz
Cura has been doing this for a long time. I know this because unfortunately it doesn't use the active/standby concept that RRF supports, so several versions ago I had to modify RRF to second-guess what Cura was trying to achieve using M104 commands.