Completely modeled new model of dice tower with catapults, improved - I hope - and a nicer design
The rubber band holders hold firmly, I didn't have to glue them.
You will need small rubber bands 25-30mm long.
I wanted to make a link for mechanical catapults without rubber bands, but I have already verified this system.
For cubes with side dimensions 14-17mm
You can find assembly instructions in this video, it's the previous tower.

The author remixed this model.
Completely modeled new model, improved - I hope, more beautiful design