April 23, 2006

315 words 2 mins read

Ballista Day 2

I finished the build on the Ballista. I built the launching platform, and got it all setup. Took a few test shots… and got a stellar 5-10 feet out it at best. I made a few adjustments, even used bungie cords. No dice. I realized that my hacked together attempt at a Ballista had failed. So I disassembled it. Only took me about half an hour.

This time I spent a good amount of time read and looking at pictures from Siege Engine.Com. They have the best infromation on the web, at least that I can find. This time around I rebuilt something that looks very much like SE’s Baby Ballista (when I get a chance I’ll take some pictures, trust me its very similar). The key difference is that I really paid attention to the Torsion springs (aka the rope). After this re-build I actually understand how they work, and how to build them properly.

It didn’t take my long to build my copy of the Baby Ballista, except for the springs, wrapping the rope took a damned long time (of course I used about 40′ of 1/4” Nylon per side). Though it has a LOT of power. My ammo of choice is golf balls (Ah, my mother will be pleased next time she goes golfing). I built a little mini sling for the balls out of a plastic bottle. I easily lofted them a few dozen feet (I’m not exactly sure how far, as it was dark at the time) over a fence. The problem is that when I cranked up the power a little bit more and pulled back the bow string the entire way — I ripped my plastic sling to shreds. So that put an end to that.

But thats ok, now I’m going to have a small denim sling made that will hopefully survive longer. Tomorrow should be fun.