This system can be sued to measure wheelchair static stability. The design's being published to allow better community development and feedback.
You can use these pages to see the instructions and to calculate theoretical stability based on scale measurement data.
I've currently just posted a version developed some years ago, with a view to some development soon. It is still a work in progress, so do bear with!
The hardware design will be published, and is similar to the version shown in the photos. We are currently working with digital scales, and I do use the calculation form.
If you do use it, you will need to establish your own protocol for best practice. The formulae used need checking, so check them first before you rely on them.
Also see these two related repositories:
https://github.com/ACECentre/MAT-doc
https://github.com/ACECentre/Wheelchair-Stability-App
Development is happening now, so get in touch or add issues to feed into this project. Thanks!