4.4 Version of Cura still has support issues

[charlism 0]

I just upgraded Cura to 4.4 and noticed it is generating necessary support. I have had this problem with the last couple of versions. My latest run in with this problem looks different than the others involving features higher up in the model that have already been reported about older versions. Attached is a model that requires support only for the pegboard pins on the back of the piece but a strange section of support is being generated for only part of a 45 degree overhang on the front. It would seem that erroneous support should be generated across the entire model's 45 degree face or not at all. The geometry should be the same all the way across the width of the model.

 

All overhangs, both for the internal holes and the external surfaces, are 45 degrees. It did not generate any support inside any of the holes. The minimum overhang for support was set at 55 degrees. The phantom support increased in size if this setting was reduced to 50 degrees and disappeared if increased to 60 degrees. 

 

This exact model sliced as expected quite a while ago with 3.something.

 

Charlie Smith

BurrHolder.25x10x3.stl

[gr5 2,224]

Not to diminish this bug but you are aware of the "support blocker" feature, right?  It's extremely easy to block support on that overhang with this feature - just takes seconds once you've done it a few times.

[charlism 0]

Thanks for the workaround. Yes I am aware of the support blocker and have used it on more complex prints. I also am aware that you can have more than one version of Cura installed. I just checked previous versions and the "bug" is in 4.1 but not 3.6. So until they squash this bug and plan to use 3.6 for prints requiring simple supports and 4.4 for complex and no support prints. I hope another example of the "bug" might help the developers find it. By the way  I think there is more going on than just the unneeded support in the front. When I actually printed the model some of the travel moves between the small supports under the pegboard pegs continued to extrude. It was not ooze but full flow in mid air during the 100 mm travel. I love the work Ultimaker is doing with Cura but I think that the code that generates support in 4.x needs a serious looking at.

Edited December 9, 2019 by charlism
Improve the voice

[charlism 0]

Photo of flow during travel only moves between supports.

[gr5 2,224]

I call that "stringing".  I usually reduce it by printing at slower speeds but thicker layers so it takes the same amount of time.

 

So maybe 0.2mm layers and 35mm/sec for all printing speeds and keep travel speed fast (200 to 300mm/sec).