Variant construction set

So, this is Variant construction set, which was originally designed about 40 year ago by one Czech company and it is still produced till nowadays:
https://www.kaden.cz/variant-stavebnice (please support the producer by buying the original set if you can).

It's a LONG time ago since I was playing with it, but I still clearly remember the hours and hours of joy and entertainment it brought, as well as the skills I acquired by building different constructions.
Recently I got into possession of one of these original sets and gave it to my son (3yo). He also likes it a lot. And then I realized that with 3D printing I can create more and new parts, limited just by my imagination. So I recreated most of the original set in SCAD and added a lot of new parts.
From the original set I only did not try to model the chain gears since the chain consists of quite small parts and would be difficult to print accurately enough. On the other hand, I added many different gears to the original one