Objective & Overview
A custom 3D printed shadow board insert designed to turn a thrifted hard case into an ultra-organized everyday carry (EDC) tech kit. Fabricated using an UltiMaker MakerBot Sketch Sprint, the project eliminates everyday bag chaos with precision slots for dual mice, wireless earbuds, batteries, and loose tech accessories.
Picked up the rugged case at Salvation Army for just $3—an unbelievable bargain over similar compact cases on Amazon going for $15 to $20. By ditching the pick-and-pluck foam for a clean, custom-modeled UltiMaker PLA insert, every millimeter of internal space is utilized while still reserving vertical clearance in the lid for cables.
Items & Fabrication Specs
| Item / Component | Model & Specs | Role / Layout Detail |
|---|---|---|
| 3D Printer | MakerBot Sketch Sprint (UltiMaker) | High-speed, reliable production run for the shadow tray & container |
| Filament Material | UltiMaker PLA | Dimensionally stable, clean layer adhesion with minimal shrinkage |
| Protective Shell | Thrifted Rugged Hard Case ($3) | Salvation Army find; impact-resistant outer shell with weather gaskets |
| Peripheral Slots | Dual Laptop Mice Pockets | Dedicated cavities for daily work and personal travel mice |
| Audio Slot | Sony Earbuds Cradle | Contoured recess matching the Sony charging case footprint |
| Battery Storage | 4x AAA Cell Organizer | Friction-fit retention holes to keep spare cells isolated and ready |
| Modular Bin | Removable Odds & Ends Tub | Lift-out organizer for SD cards, flash drives, and small adapters |
| Overhead Reserve | Lid Clearance Void | Z-axis buffer to drop one or two coiled cables directly on top |
Visuals
Build Log & Engineering Notes
Thrift Store Find & Caliper Profiling
Found the base hardcase at Salvation Army for $3, saving about $15 compared to ordering an equivalent sized Pelican-style case from Amazon.
Removed the crumbly generic foam and mapped the internal draft angle, rounded corners, and interior depths with digital calipers to create an accurate boundary shell in CAD.
Shadow Board Cavities & Modular Tub
Laid out the footprint in a 5S shadow board style: distinct pockets for two laptop mice, a tailored socket for the Sony earbuds case, and a four-slot retention array for AAA batteries with quick-access finger bevels.
Modeled a small, drop-in utility box with lift tabs that sits flush in its own bay—acting as a contained organizer for small flash drives, microSD cards, and micro adapters without them rattling around.
UltiMaker MakerBot Sketch Sprint Print Run
Sliced the insert for the MakerBot Sketch Sprint using standard UltiMaker PLA. The Sketch Sprint handled the job with impressive print speed and dead-on dimensional accuracy.
The PLA's low shrinkage factor made the outer perimeter press-fit snugly against the inner walls of the case without warping at the corners, ensuring no perimeter shifting when removing accessories.
Overhead Lid Stash Check
- Tuned the pocket depths so the highest peripheral sits low enough to leave clear space for quick-deploy USB-C charging cables resting on top.
- All parts, mice, and batteries drop in with smooth clearances and stay locked when the case is latched and shaken.
- Future revision: Consider printing a snap lid or sliding magnetic lid for the loose parts container to prevent tiny cards from jumping out on heavy drops.