Here is a in-progress drawing of the trigger assembly. I am designing it to be cast and bolted to the slider. I suppose the parts can be forge welded as well, not sure, but my blacksmith will advise me. These parts will be cast from bronze, as I don't have iron working skills and want to do as much as I can myself, and keep the work as close to the practices (as far as we can tell 2,000+ years later) of the ancient world as possible.
The design I am working on closely follows Heron's (a Greek engineer) description of a cheiroballistra trigger. The cheiroballistra is a very advanced iron-framed machine depicted on Trajan's Column, and is the last major development in torsion-powered war machines from the classical period. The wooden ones I am concentrating on are much earlier designs, but it is assumed they were used wiell into the Empire period.
These parts are for my smaller manuballistas / scorpio-minors / small or lesser scorpions, but will be easily adaptable for use on the larger 2" machines, as well as a future gastraphetes, or belly bow, which is on my future list of projects to undertake. Notice the use of a linear or sawtooth ratchet on the sides of the weapon's case. This was, to the best of my knowledge, a system favored by the Greeks, the Romans having introduced the circular ratchet. The 2" machine will use the circular ratchet system, while the hand held machines will use the earlier linear ratchets.
By the way, if anyone feels that these arrow firing machines do not belong in PA (I myself debate whether this constitutes primitive archery as we think of it, but do feel it does), let me know, and I'll quit posting about them.
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