Unrelated:
Very happy and satisfied to see Macmaster-Carr store links for several of the parts in the materials list. MC is the best.
EDIT:
In this post[1] the author mentions the Pruse MK3S[2] but I am not sure if that is what is used for all of the projects on the site ...
[1] https://back7.co/home/learning-to-scale-small-manufacturing-...