04: 3D Scanning and Printing

Goal: 3D print a snap-fit electronics case
Software: Fusion 360, PrusaSlicer
Hardware: Original Prusa Mini (3D printer)
Prior Experience: CAD (01 and 02), minimal 3D printing experience
New Methods: 3D print, slice, snap-fit w/ plastic (PLA)

[audio on to hear snap]
Details:

Assignment this week was to 3D print an object that can't be molded/casted
Instead, I chose to focus on snap-fit electronics enclosures (more relevant to my final project)
This resulted in a large graveyard of attempts (see below)
Final solution was surprisingly simple
Start by designing the case in Fusion 360
See 01: Computer-Aided Design for intro instructions
Now, simply add an inner lip to the lid
Extrude each of its 4 inner walls >1mm
Combine them into 1 body
Extrude to form lip >1mm
These features must be >1mm or they will easily break off
Combine lip with lid to form 1 body
Check to make sure lid/bottom are still flush

Option: fillet lip edges (I find that non-fillet snaps tighter and is more robust to use)
Export each body as mesh (.STL) and open in PrusaSlicer
Slice with generic settings for PLA filament and 3D printer model
Export .gcode to USB and proceed with print

Tested multiple fillet options on lip: none, corner, and all
I find that non-fillet snaps tighter and is more robust to use
Almost too tight
It was surprising to me how simple this solution was
I at least expect to have to offset the edges to account for innaccuracy
Before finding this solution, I attempted other mechanisms inspired by this guide from Neil
Mainly attemped "snap" and "buckle"
All failed due to brittleness of small PLA features

Resources:

Dana Gretton's 3D printer and advice

Files:

[next week]