Part of Tribes and Patreon November release. https://www.patreon.com/makingtlon
Part of the Ship Main Deck set.
These ballistas have two bases (to simulate a "turning" structure and one fixed), and two versions: one with a regular bolt in and one whithout a projectile, so that you can slide in the dart you prefer. These ballistas can be glued or left movable thanks to the very simple but effective hole/cylinder mechanism. Finally, there are combined versions that have the base and the ballista in a single file, but their mesh is not suck together: if you print them and remove the supports they should be able to tilt without any need for glue and assembly.
All the models are presupported and test printed.