1 The project
I've had five Raspberry Pi 4 Model B boards sitting in a drawer for too long. I want them running as a little cluster, in one box, on the desk. Not a tangle of USB chargers and a cheap acrylic stack, but something I'd be happy to look at.
The brief I gave Claude was short:
- Standalone. One mains lead in and nothing else. The boards run on Wi-Fi, so there are no network cables.
- The power supply goes inside. A Mean Well RS-50-5, 5 V at 10 A, which needs wiring in properly.
- Two blower fans that I already have, GDSTIME 5 V at 0.14 A each.
- Show the boards. I can buy perspex sheets for the sides, and I want to see all five boards and their LEDs.
- Upright if possible. I'd prefer something that stands vertically.
- Printed on the A1. I'll buy PETG from Bambu if it's needed.
Then I went out for the morning and left Claude to it. It ran the whole thing: the repo, the wiring, the BOM, ChatGPT for the first renders, and four concepts in FreeCAD. These posts are my write-up of what came back.
The rules
A few rules came with it, some from me and some from earlier projects.
- PETG, not PLA. The PLA holder for my home lab's mini PCs lost its grip on the hottest one after a few months near 80 °C. PLA starts to soften from about 55 to 60 °C and creeps under a steady load well below that. Every part that holds a board, the power supply or a fan is PETG.
- Mains stays boxed in. The power supply's input terminals and the inlet sit in a closed compartment that takes a tool to open, and the power supply's metal case is earthed.
- Everything fits the A1. Its bed is 256 × 256 × 256 mm. The checks keep 6 mm in hand, so no part may be over 250 mm on a side.
- It mustn't fall over. It has to stay up when tilted 10° in any direction, the same self-restoring rule I use for stands (AI workstation, part 6).
- Perspex in flat rectangles. A cut-to-size supplier can make any of them, and there's nothing to drill.
- Use what I have. My screw kits cover M2.5 for the boards and M3 for the power supply. Small parts like Wago connectors are fine to buy.
How it went
Claude asked ChatGPT for four directions first, in five parallel chats, and got photoreal renders back in a couple of minutes (2). Then it modelled the parts I own from their makers' drawings (2.1), and built four concepts on top of them (3). The wiring has its own post (1.1).
The CAD runs through FreeCAD's MCP bridge, the same setup as the AI workstation (1.1 there). The project's code, models and BOM are in a private repo, 3dp-pi-stack.
What I don't know yet
- Which GDSTIME blower these are. Claude assumed the 50 × 50 × 15 mm size (a 5015), which is the one GDSTIME sells near 0.14 A. I need to read the label and measure one.
- How hard the boards will work. Idle, they barely warm up. Flat out for hours, they'll need every bit of the airflow.
- Which IEC inlet I'll buy. Its cut-out is modelled as 47.5 × 27.5 mm until I have one.