Thing that current Cura sucks at that it would be cool if New Cura didn't suck at...

[nick-foley 5]

When trying to print nested parts in the same STL, Cura doesn't maintain top/bottom thickness rules when things are stacked on top of each other but not quite touching.

Here is an STL that shows exactly what I mean in a somewhat complex use case, but the basic principle is simple:

 

Imagine I'm trying to print a cube with 2mm walls + top + bottom, and 20% infill. I dial my settings in to Cura, and I get that result.

Now, instead, imagine my STL was actually two cubes, stacked on top of each other, but offset by 0.3mm or so... so that they could print in the same file, and pop apart like a part comes off a raft. I could in theory, print a huge stack of cubes in one print like this. It would be great.

What Cura does in this case, though, is not what you want: Cura treats the near-touching tops and bottoms of the cubes as a contiguous volume, despite the 0.3mm offset, and doesn't print a proper top or bottom on either cube. The tops and bottoms of these cubes are an open mess of infill and not the desired & clean 2mm

In the linked file, you can see this in the central part in which the small part is a functional part but also acting like support material for the larger part.

I'm not sure if the Cura Uranium fixes this, as the layer view isn't showing infill paths and old Cura can't seem to preview new Cura's gcode files.

If anyone has a fix for this I would be interested to hear it.

Edited May 24, 2015 by Guest

[Dim3nsioneer 558]

Maybe I had not enough coffee yet today but I don't get the reason for stacking objects with a horizontal gap. I would never expect the upper object to have a clean bottom.

Hovever, the way Cura deals with such situations might have some space for improvements.

[IRobertI 521]

Yup yup, that has annoyed me for quite some time as well. I asked about it a while back but I've already forgotten the reason it does that... I do remember it had something to do with the top/bottom thickness. Reducing that thickness "fixes" the problem. But of course it's not a real fix as 2-3 layers of top thickness is very rarely enough.

And nope, the latest beta does not fix it either.

[Labern 775]

I have the same problem with my Ultimaker robot with moving parts. The gap between the body and head has this issue. Still ended up printing ok but not the best situation.

[nick-foley 5]

Maybe I had not enough coffee yet today but I don't get the reason for stacking objects with a horizontal gap. I would never expect the upper object to have a clean bottom.

Hovever, the way Cura deals with such situations might have some space for improvements.

The bottom surface of a part printed with a raft turns out pretty clean, no? This is the exact same principle.

It is useful when nesting parts, printing interlocking parts, or generating your own support material in CAD prior to Cura.

Edited May 24, 2015 by Guest

[Dim3nsioneer 558]

The bottom surface of a part printed with a raft turns out pretty clean, no? This is the exact same principle.

It is useful when nesting parts, printing interlocking parts, or generating your own support material in CAD prior to Cura.

OK, but with a raft you have some material in between the lower top (print bed) and the upper bottom? But as mentioned before, it could be improved.