I have a Caribou and wanted to install a raspberry pi on the back of the z-axis.
I loved this case for the Pi so i've made some holes to be able to use T-nuts to install it.
I've used these T-Nuts.
https://www.printables.com/model/117699-drop-in-t-nut-3030-profil-m3-m4-m5
For the second Model I've modified the T-Nut with a groove so you can keep the case aligned while screwing them.
I've used these M3 screws with a small head from this kitt. I don't remember what length it was.
https://www.amazon.co.uk/gp/product/B0B2543T68/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
Thanks to the original makers
The author remixed this model.