STM32 BluePill+ plus case

This is really a "first cut" of a case to house an STM32F103 WeAct Studio BluePill+ development board.

The design prints in two parts and can be connected together using a piece of 1.75mm 3D filament as the pin in the hinge joint. You can use a soldering iron or heated flat head screwdriver to heat-set the pin in place at either end.

The two halves of the case are printed with their "flat, horizontal" sides against the bed (i.e. the top of the top half and the bottom of the bottom half). No supports or brim are needed.

The example photos were printed in clear green PETG on a Elegoo Centauri Carbon printer. The model was developed using FreeCAD v1.1.4.

The design was built rapidly as a "proof of concept" and there are a number of issues that I'd address if I ever get around to making a new version:

• The internal cavity is quite neat on the PCB. I can get my two boards to fit into my case (with a satisfying "snap" - and pretty firm hold on the board) - but you might have issues with different boards or 3D printers/filament. In the future I'd add a bit more tolerance around the PCB.

• It only allows (but doesn't require) male pins to be soldered to the underside of the board. These are intentionally inaccessible from outside the case (I wanted to "short-proof" some demo boards). The pin space could be opened out significantly to allow for proto board attachments or female connectors.

• The access holes for the 3 tac switches on the board aren't lined-up the best (but should be usable with a piece of 3D filament to push the buttons). A future board might have print-in place captive pins or flexing buttons attached to the top case.

• The knuckles of the hinge are quite neat against the opposing half of the case, so they can grind a bit when you open/close it.

• The retention clip has dubious sturdiness (Being printed vertically, with layer lines across the bending plane). The print I have seems fine, but use and time may prove otherwise. I thought about adding some fluting to the outside, but couldn't be bothered. A future version might use a separate retention clip printed horizontally. I also would consider recessing the clip into the base of the case and extending it right to the bottom to give a cleaner outer profile.

• A print-in-place hinge might be considered, but due to the symmetry of the BluePill+ board, it'd likely need to be printed "inside down" with a lot of support material to work.

Use of AI: I used Kagi's inbuilt AI assistant to guide me through FreeCad's tooling to be able to develop this model (I'm more familiar with OnShape and still learning FreeCAD). However all the tool use was directly with my own hands fumbling around (No agents or generated models).