01-04-2008, 03:10 PM
Hi Randi.
The only way to find out how parachute cord would work would be to try it out, eh? We would than need to rewind new springs out of another type of material to compare performance, and I’m not sure what criteria to use in that kind of test. Let’s talk about it Saturday. And, remember the larger scorpion is hot on the heels of this manuballista, though the manu will be completed sooner, pretty soon after I cast the various metal parts and incorporate them into the machine. I am also planning to build a second almost identical manuballista (I’ll explain that plan when I see you, and why – getting a thickness planer today to cut down on a lot of hand work!), so maybe we can wind one with horsehair rope and the other with para cord?
I can see now you can fit a LOT of cord into the spring holes!
The machine is at home, resting against my desk, and I can’t recall this second which way I twisted the springs (it was past midnight when I finished), but you will see for yourself.
And, last, I haven’t yet made a bowstring, or cut the bow sting notches in the ends of the arms. I am thinking I may need to make a bastard string to facilitate stringing the machine, such as used for heavy crossbows. Part of the stored energy of course is in the unspanned string under tension before cocking, and the string, among other things, will prevent the arms from slamming into the frame’s outer uprights upon firing. However I make the string, it has to be very, very strong.
The only way to find out how parachute cord would work would be to try it out, eh? We would than need to rewind new springs out of another type of material to compare performance, and I’m not sure what criteria to use in that kind of test. Let’s talk about it Saturday. And, remember the larger scorpion is hot on the heels of this manuballista, though the manu will be completed sooner, pretty soon after I cast the various metal parts and incorporate them into the machine. I am also planning to build a second almost identical manuballista (I’ll explain that plan when I see you, and why – getting a thickness planer today to cut down on a lot of hand work!), so maybe we can wind one with horsehair rope and the other with para cord?
I can see now you can fit a LOT of cord into the spring holes!
The machine is at home, resting against my desk, and I can’t recall this second which way I twisted the springs (it was past midnight when I finished), but you will see for yourself.
And, last, I haven’t yet made a bowstring, or cut the bow sting notches in the ends of the arms. I am thinking I may need to make a bastard string to facilitate stringing the machine, such as used for heavy crossbows. Part of the stored energy of course is in the unspanned string under tension before cocking, and the string, among other things, will prevent the arms from slamming into the frame’s outer uprights upon firing. However I make the string, it has to be very, very strong.
Dane Donato
Legio III Cyrenaica
Legio III Cyrenaica
