Screw and Fastener Guide
Edit on GitHubThe fasteners used in the beacon case: M2/M3 hardware, brass inserts, and the mounting pattern for boards and the antenna.
Screw and Fastener Guide
The difference between a prototype and a field device is often the fasteners: what holds the board, the battery and the antenna when the case gets dropped.
The hardware set
| Fastener | Use |
|---|---|
| M3 x 8 - 12 mm | Board mounts, case screws |
| M2 x 6 mm | Small boards, OLED |
| Brass heat-set inserts | Printed cases: threads that survive reuse |
| M3 standoffs | Stacking the ESP32 and GPS |
The brass insert trick
Screws into bare printed plastic strip the threads after a few cycles. Heat-set brass inserts (installed with a soldering iron) give real threads that last. The 3D Printing Guide covers the installation.
The mounting pattern
| Component | Fastener | Note |
|---|---|---|
| ESP32 board | M3 standoffs | Keep 2 mm clearance under the board |
| OLED | M2 | Thin panel; tighten gently |
| GPS module | M2 or tape | Vibration-sensitive antenna: secure firmly |
| Antenna mount | M3 through the case wall | The SMA flange (see Antenna Mounting) |
The torque rule
Small plastic threads need light torque: “snug, then a quarter turn less”. A stripped thread in a sealed case is a field repair with the case open in the cold. Use thread-forming screws in plastic, not machine screws without inserts.
The corrosion rule
Stainless or zinc-plated screws only. A rusted screw in a sealed case is a water path and a future frustration. In wet environments, add a drop of thread sealant on the case-screw threads.
Related pages
- Case Cutouts Guide for the holes
- 3D Printing Guide for the printed parts
- Assembly Sequence for the order