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So far, the wood (all ash) weighs in at about 7 pounds. I expect it to at least double when it is finished.
It is a handy little machine, from what I can tell, but I think you are right, I am not a he-man, so firing it would necessesitate some sort of rest. A handy wall would work, but I also plan to make some sort of portable monopod, bipod, etc.
Indeed, it is based on the Xanten machine. I was too impatient to wait for the museum to publish exact specs, so I am going by the photos and standard ratios of these machines. While it wont be a precise replica of the Xanten weapon, I am guessing there was a variety of small machines in existance, unless the Xanten was a single unique machine (doubtful).
I imagine that machine to be like a Roman squad weapon, the M60 or SAW or MG42 of ancient times. Bet it would have come in handy for hunting large game, as well
Dane Donato
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Quote:Bet it would have come in handy for hunting large game, as well
Elephants?
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Red deer, reindeer, boars, bear, hedgehogs, your random gray kangaroo, you know, things like that... :wink:
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Saepe veritas est dura.
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I can't help but think these small machines were possibly used in seige towers, or even in towers of forts and towns, rather that manportable weapons for the battle field....IMHO!
Visne partem mei capere? Comminus agamus! * Me semper rogo, Quid faceret Iulius Caesar? * Confidence is a good thing! Overconfidence is too much of a good thing.
[b]Legio XIIII GMV. (Q. Magivs)RMRS Remember Atuatuca! Vengence will be ours!
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You guys do know I was kidding about game?
Gaius, I do see that being a prime role for these small machines, as you would have to expose yourself a bit while cocking it if in a field situation, and it would have been very tiring to hump it on the march.
Duncan, question: I'm strongly leaning toward the Greek style sawtooth ratchet system, ala the gastraphetes (and one day, I want to build one of those with a real composite bow, something I don't think anyone has ever done before). It seems logical to use this system, which is also very safe, all things considered. Think I am on the right track?
As I write this, I'm covered with shavings and sawdust from a session with the plane. Soon, more pics to post.
Dane Donato
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Quote:Duncan, question: I'm strongly leaning toward the Greek style sawtooth ratchet system, ala the gastraphetes. It seems logical to use this system, which is also very safe, all things considered. Think I am on the right track?
Absolutely.
If you look at [amazon]Greek and Roman Artillery 399 BC - AD 363[/amazon] Plate B, you'll see the linear ratchet which Marsden preferred. He reckoned it was far superior to Schramm's version, which you can see in my Plate C.
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Well, that is decided then. Thanks!
I've noticed that some modern engine builders bolt the sawtoothed ratchets to the side of the machine, such as Alan Wilkins does in his machine shown on Page 41 of your Greek and Roman Artillery 399 BC - AD 363.
However, it looks to be more appropriate to fit it into a slot into the wood itself of the stock (or maybe even cast as one piece and bolted or nailed into the wood in a slot chisleled into the stock). Either way seems to make a lot of sense to me, rather than bolting it onto the side of the stock.
Futher, do you think I should adopt it for my larger scorpio? Or use the round rachet the Romans seemed to favor. One machine I've seen uses both concurrently.
Dane Donato
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By the way, here follows three shots of the larger scorpio I'm building. The frame size is 18" by 20", and you can see my pug Davenport for size comparision (plus, I love showing her off. I'll have to find the shots of her as a legionarie, with the gladius I made for her, with real bone handle and wood and leather sheath, and her red tunica).
Dane Donato
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Another of the frame. I used large hardwood dowling rather than mortise and tenon joints for this, which will be more than strong enough for the forces at work as the bow is pulled back and locked in place.
Dane Donato
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Last one. This shows the glueup of the stock and dovetail slot. Alas, I didn't create a real dovetail slot with chisels (and my router is far too small to handle such a large job), but it will look fine when done. The slider has been pegged and glued already, after this shot was taken.
Dane Donato
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Quote:One machine I've seen uses both concurrently.
Belt and braces! I tend to think of the circular ratchet as a Roman innovation, so it would go along with a Vitruvian spring-frame (i.e. single central stanchion, rather than a pair of middle stanchions).
But, let's face it, you're the boss on this one!
Further to the linear ratchet, you might find this diagram from Marsden useful (in case you don't have his Technical Treatises book). It shows three possible designs, of which the middle one (labelled b) was found to be the most efficient. (The one labelled c is Schramm's rather complicated design.)
[size=75:1cmny3xt] Wow! I didn't think I'd scanned it so big![/size]
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Thanks, Duncan, for posting that image. Yes, the middle option is the one I intend to use with the small scorpio. As for both the linear (ha, that is the word) ratchet and circular design, for my bigger machine, just the wheel style Roman one, I think. these project have you thinking and considering all the way through. And this board is great for just thinking out loud, so to speak.
Dane Donato
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Dane
You say you are making the Manuballista from Xanten. What inner modioli diameter are used?
Another question. I have found a realtivelly cheap way to get some horsehair cord. For american people, try to found that on horse equipment shops. Are called "mecate" and are a kinfd of reins.
From european people, i have found that dealer:
http://www.stormy-horse-ranch.de/shop/c104.html
See at the bottom of the page:
It size is almost 7 meters, but the diameter is wide and we can easily divide it in two cord of 7 meters.
Real horse hair cord!
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Cesar, thanks for the horsehair tips! I will look into that.
I am keeping the inner diameter close to 1 3/8". I will enlarge the holes after casting the modioli somewhat.
One mistake I feel I made was not making the two inner uprights closer to the center of the spring frame, but can componsate a bit as I continue construction. Since it isn't a precise copy of the orginal artifact, perhaps not as crucial. Once the paper is published (or exact plans published), I may revisit and make another small machine.
Dane Donato
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Quote:You say you are making the Manuballista from Xanten. What inner modioli diameter are used?
Not published yet ... unless someone knows different?!
From what I could glean in 2005, from Hans-Joachim Schalles at Xanten, the inner diameter was approximately 45mm (1¾"). Significantly larger than Dane's, which has a modiolus of 35mm.
As you know, this would have an overall effect on the size and weight of the machine, as everything would be scaled up.
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