Roman-Style Catapult

thingiverse

UPDATED: https://www.thingiverse.com/thing:5139005 I made a small catapult for my nephew, so that he could lay siege to his brother's castles. Quick and crude: there's a string trigger system, but it proved cumbersome and it was far easier to just hold the throwing cup to fire. The real ones either had a rope trigger worked together with a winch or used a mechanical winch and trigger system. There's space on the frame if someone wanted to design one. This style of catapult shows up in the Roman period and disappears around the time trebuchets become dominant. Rather than a counterweight, these employed tension from wetted natural fibre ropes wrapped around a greased axle. The lack of counterweight made this style of catapult easier to relocate and re-aim, which is why their use continued for as long as they did. The conversion of rotational kinetic energy of the throwing arm into kinetic energy of the projectile is significantly lower than what is observed with a trebuchet, thus the range of a trebuchet proved immensely superior. As well the safety hazards associated with the high-tension ropes were considerable.