Answer on Orsova ballista Edit
you might have a look at our ballista which we have been building, improving and testing over a period of four years.
During this time, we have been using different kinds of animal fibres (among others, including horse hair and catgut) for the springs, also comparing these to Perlon, different arms (wood, combined wood-horn-iron arms according to Ps.-Heron, and with these two kinds, one stiff, one elastic like a compound bow arm) and different sets of arrows (conic, cylindrical). We have reached speeds up to 86 m/sec and distances beyond 520 m. Targetting was easy at 120m, and the energy transferred equalled that of a modern assault rifle bullet (large calibre).
Our research was assisted by the German Bundeswehr, and our results will be published next year.
Prof. Dr. Burkhard Meißner
Helmut-Schmidt-Universität, Universität der Bundeswehr Hamburg
126.96.36.199 12:44, October 16, 2016 (UTC)Germany
Impressive work. Your results are roughly on par with what Nick Watts has achieved.
My cheiroballistra project has been on hold because we've been renovating our apartment for several months now (goes slowly on evenings/weekends). The delay is annoying, because getting the cheiroballistra to full power (~150+ joules) with nylon is very close (<20 hours of work). So far my best result was 117 joules, but the springs were not tuned as tight as they are now. Based on my tests velocities of 90m/s+ are clearly achievable with war-weight bolts. I hope to resume my project before Christmas. After full power tests I'll probably start making miniature onagers to compare characteristics of nylon and various types of sinew cord/rope.
I've been in touch with many of ballista enthusiasts/researchers and I've been planning to setup a mailing list where these topics could be discussed. If you're interested in joining such a list let me know.
Btw. you can email me at email@example.com.
Samuli.seppanen (talk) 06:16, October 17, 2016 (UTC)