Inefficient routing since ver. 2.7.4
Hello,
when printing some kind of mesh, for example a hexagon one, the order in which the hexagons are printed seems to be quite random, when using the recent Prusaslicer releases.
This results in a lot of unnecessary print head movements, thus longer print time.
Version 2.7.4 is the last one known to me, which still did routing in more sensible order. Please see the enclosed pictures, made with versions 2.7.4. and 2.9.0.
Why has this changed so, and is there some setting that I could use to make 2.9.0 behave more like 2.7.4, in this respect?
Thanks and regards,
Kari
RE: Inefficient routing since ver. 2.7.4
I don't believe there is any setting you can change to make it more like 2.7.4. You could try and play around with the seam settings or change the slicing back to classic instead of arachne but I don't think you will have much luck.
There are MANY issues open on the PS github regarding path planning so its not like this is an unknown issue. Just go there and select the Path planning tag, https://github.com/prusa3d/PrusaSlicer/labels/path%20planning?page=2&q=is%3Aopen+label%3A%22path+planning%22
People have been complaining about it since way before 2.7 though, almost as long as the software has been available.
In fact one of the longest issues about it specifically complains that it still sucks in 2.7.4 https://github.com/prusa3d/PrusaSlicer/issues/11658
RE: Inefficient routing since ver. 2.7.4
OK, thanks for your answer. I just happened to notice this after upgrading from 2.7.4, because I then had a project involving a hexagon mesh, similar to the test print I used in the images above.
If I slice the same piece with Cura or Slic3r, then the routing is much more sensible.
Perhaps I'll move to use Slic3r then, although otherwise I like Prusaslicer interface and usability more... :/
RE:
Answering my own question... I just discovered the problem. It's the Arachne perimeter generator. Using that, the routing is inefficient (in my examples & experiments, at least).
When I switched to Classic, then the routing is a lot better. With one of my recent prints (drain filter), the print time was reduced from 42 to 30 minutes.
I thought to share this, just in case someone else would be wrestling with a similar problem.
(So, probably the Prusaslicer version change wasn't the culprit, after all - I just happened to change the perimeter generator setting at the same time, and couldn't make the connection... d'oh!)
RE: Inefficient routing since ver. 2.7.4
As I mentioned in my original reply, classic routes better than Arachne in many cases which is why I suggested trying it. It doesn't always though and seems to be geometry specific. It's unfortunate that Prusa changed the DEFAULT on its profiles to Arachne. So you might not have changed it at all.
Many of those github issues I mentioned also complain about the fact that in many cases the routing between classic and arachne is very different.
I would expect there to be some difference purely down to the fact that with variable width extrusion there could be different numbers of perimeters actually printed but the fact that its so wildly different and all over the place suggests a bug in the path planner, or at the least its needs a different optimisation when using Arachne.
RE: Inefficient routing since ver. 2.7.4
Oh sorry, I missed that Arachne part in you reply, my mistake. That looks to have been the culprit indeed, in my case. Thank you for your answers.