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prusa3d / PrusaSlicer

G-code generator for 3D printers (RepRap, Makerbot, Ultimaker etc.)
https://www.prusa3d.com/prusaslicer/
GNU Affero General Public License v3.0
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Draft shield has no brim #8347

Open espr14 opened 2 years ago

espr14 commented 2 years ago

Description of the bug

Some filaments have high tendency to warp after extrusion so a brim is used to keep the first layer attached to the bed. Shield blocks the cool air so the warping is smaller. But the shield has no brim so the shield can detach during printing. This happens if object's first layer is much smaller than the object in the upper layers or if the object is tilted.

Project file & How to reproduce

  1. generate a cube
  2. rotate it 45° in X (cube will stand on the edge)
  3. turn brim on
  4. turn skirt on
  5. switch draft shield to Enabled
  6. switch to preview screen and render the model

Cube has brim but draft shield has not.

Checklist of files included above

Version of PrusaSlicer

Version 2.4.2+linux-x64-GTK3

Operating system

Linux Mint 20.2 Cinnamon

Printer model

Prusa i3

Gregor-Gregor commented 2 years ago

Draft shied usually helps with draft vulnerable filaments. But this also means the draft shield itself is vulnerable, may warp and detach, unless number of loops is increased... increasing also waste of filament to construct unnecessarily thick draft shield. Brim to the draft shield - yes, please.

jbernardis commented 2 years ago

I too vote for this feature. If I'm having enough trouble with adhesion that I need to use a draft shield, then it makes sense that that shield will aldo have trouble with adhesion. A brim on the shield will mitigate this.

n8bot commented 2 years ago

I use the draft shield to purge tool changes on my IDEX, but I also needed a brim for the skirt so I have an open PR to include this: https://github.com/prusa3d/PrusaSlicer/pull/7305

subatomicglue commented 1 year ago

I'd love to print the part without a brim, but with a "brimmed" draft shield to help it stick. a much needed feature. +1

Additionally Much Needed for similar reasons - draft shield should not only be convex hull as it is now, but should follow the same path as the brim for the tightest draft shield possible! (I suppose it could be nice to select concave or convex). Often there are times when the draft shield is quite far away from some interior feature of what I'm trying to shield, kind of defeating the purpose. Additionally, the draftshield sticks to the brim while convex, but in concave parts, the draft shield can actually float off the build plate, making it unstable! (same argument as above, we use draft shield for ABS, but ABS warps, therefore, we need a brim to help keep the draft shield from warping/detaching from the plate.).

Illustrated, I hope you see the benefit of a concave hull for the draft shield!: image image

Because it is a concave hull, and the brim is a convex hull, you see that 1.) the draft shield is quite far away from some parts of the model, making these parts mostly unshielded... 2.) the draft shield totally misses the brim in some parts, therefore "floating" on the bed, not attached (well).

Gregor-Gregor commented 1 year ago

Good idea, subatomicglue. 👍

I was just thinking about similar concept of a 3D draft shield, following the shape of the object all along Z-axis as well, like a glove (with all its concavities).

There are several issues of such a 3D draft shield to be taken into consideration, eg.:

Nonetheless, such a 3D draft shield (brimmed at the bottom, of course) should allow using even most draft sensitive materials without an enclosure.

Cheers

subatomicglue commented 1 year ago

Really good idea.

Order of work that seems smart, IMHO:

Each of these increments would (likely) build on the previous, and provide incremental value to users... And the 3D one feels like some R&D (harder, more to research/discover), if I had to guess.

GMeyerGMeyer commented 1 year ago

Would love to have it too.