this post was submitted on 18 Feb 2024
119 points (93.4% liked)

3DPrinting

15651 readers
192 users here now

3DPrinting is a place where makers of all skill levels and walks of life can learn about and discuss 3D printing and development of 3D printed parts and devices.

The r/functionalprint community is now located at: !functionalprint@kbin.social or !functionalprint@fedia.io

There are CAD communities available at: !cad@lemmy.world or !freecad@lemmy.ml

Rules

If you need an easy way to host pictures, https://catbox.moe/ may be an option. Be ethical about what you post and donate if you are able or use this a lot. It is just an individual hosting content, not a company. The image embedding syntax for Lemmy is ![](URL)

Moderation policy: Light, mostly invisible

founded 2 years ago
MODERATORS
 

I think I found a counterexample to the common wisdom that more walls always create a stronger part.

The pictured S shape is 1.5mm thick, so printing with 2 walls leaves no room for infill. My testing wasn't very rigorous, but it seems that the hybrid structure of walls + rectilinear infill is 10-20% more rigid than walls alone. The infill adds strength by cris-crossing between adjacent layers.

I think it's fine to include a concentric top/bottom layer, but multiple identical layers weaken the part. I also tried 0 walls (infill only) and that was garbage.

you are viewing a single comment's thread
view the rest of the comments
[–] elrik@lemmy.world 3 points 9 months ago (1 children)

Really interesting! I wonder what would happen if you combine these two properties. Suppose some length of the middle is all walls, and the hooks are infill, or vice versa. Is there an optimal mix that maximizes the weight it can support in your testing, or have you found the optimal configuration (with infill along the entire length) already?

[–] p1mrx@sh.itjust.works 1 points 9 months ago* (last edited 9 months ago)

I haven't done any tests where the tensile/breaking strength is relevant, just rigidity. Maybe it's possible to optimize the infill based on finite element analysis or something, but that's not a rabbit hole I'm looking to go down.

I have tested that an all-walls sandwich (PrusaSlicer "solid infill every 3 layers") does not improve rigidity. So far nothing beats 1-wall + rectilinear in that department.