Timberkits Ballista
The Ballista is one of three "Medieval Weapon" kits. The other kits are the Catapult and the Trebuchet. The weapons are working models meant to replicate the loading and firing of the real thing. Unlike most Timberkits models, the weapons do not involve any continuous motion. But the models do require some thoughtful loading and tuning to maximize the range and accuracy of shots.
Finished model.
Note the winch block for winding the winch drum and drawing the trigger back to the firing position. The instructions call for the winch block to be on the left as shown. But I'm right-handed. So if I had to do it again I would have mounted the winch block on the right side of the winch drum.
Finished model. I should have mounted the winch block on the right side of the winch drum.
Finished model.
Box, parts and instructions.
My trigger was hitting the stop peg before the latch engaged. So I cut a tiny sliver off the tail end of the trigger at the red arrow shown below. The picture below also shows a close-up of the bolt.
Trigger and bolt.
For long accurate shots it's important to have the tension arms straight and level with the top of the firing channel. It's important to have equal tension on the arms. I started by winding the ratchet units opposite of their intended direction. Then I inserted the tension arms near the tops of the neoprene bands and wiggled them down toward the middle as shown below.
Wind the bands opposite of their intended direction and insert the arms.
Next I wound the ratchet units in their intended direction such that I ended up with an equal number of band twists above and below each tension arm. Finally I wiggled the arms a little more until they were perfectly straight and level with the top of the firing channel. My Ballista fires the bolt about 5 or 6 feet.
The neoprene bands are wound and the Ballista is ready to load.