[The Mekon (John Briggs)]

Over the past few months I have been slowly building this scaled down medieval siege weapon. Today was the first test firing and it went rather well. My son is in a medieval recreation and fighting group and it is hoped to take it to one of their events once proper gatherings are allowed.

The arm is 2.8 meters, the counterweight can be varied from 42 to 85 kgs.
It has been built to fit in a box trailer for transport - otherwise it may have been a bit longer.

Some interesting physics is involved. Today I learnt why it is best not to "dry fire" the weapon. Doing so makes the whole machine buck. But firing with the correct weight projectile and achieving a good throw transfers most of the energy to the missile, and the machine hardly moves - all very much fun!