Free plans for a home-built Camera Obscura released under the CERN OHL can be found at the bottom of the webpage found here:
I attended the International Conference on Design Creativity at Bath Uni in 2018 and met a couple of Graphic Design lecturers there. We got talking about the links between drawing and design creativity. They had been putting together some laboratories containing optical drawing aids to help the students train their observation skills. They were able to buy commercial Camera Lucidas, but Camera Obscuras have not been available commercially since the 1980s. I completed a low-cost home built design I had been working since 2007 and released it under the CERN OHL.
The files are hosted on a personal web page, but I’d like suggestions about better ways to share hardware designs. Since my book is now substantially out of print I’d like to close my webpage, but I want to be able to share hardware designs, teaching podcasts etc.