Crossbow Cocking Systems.
I am 68 and live on a sailing catamaran here in the Philippines, a country where non-citizens are not allowed to possess a firearm legally. As a teenager I tried making a crossbow using a section of a car leaf spring for the prod. Then, I was not familiar with tempering and found it impossible to cut the leaf spring I scrounged into the appropriate shape. For strength I was planning on making the stock out of three sturdy steel pipes welded together so the top two formed the groove for the bolt to rest in. To span such a powerful prod, I planned on using the screw from a scissors jack since I figured that if it could easily lift a car, it should be able to draw the steel cable I was planning to use as a bow string. The screw would be permanently mounted to the stock and all that would be needed to turn it would be some kind of handle at the back, with a preference for one that stayed attached as a lost handle would render the crossbow useless.
For a release mechanism, I planned on using a medieval design where a solid steel "nut" retains the cable until it was released to spin by squeezing a simple lever running along the tiller (old term for stock) which moved the other end of the lever off of a flat area on the bottom of the nut, allowing it to turn and release the bolt. Probably more information than you really wanted, but I thought it might work by keeping it simple and strong.
For use in our medieval recreations, some make lighter crossbows which use an even simpler release mechanism, consisting of a hardwood dowel or metal pipe mounted vertically in the stock which retains the crossbow string until a curved matching piece pushes the bowstring up when a trigger is squeezed. The top of the dowel is the same height as the center of the butt of the bolt. Since the targets are other fighters in armor, there are restrictions on draw weight and the bolts are blunt. When we first started combat archery we were using 30 pound regular bows and arrows tipped with modified bird blunts and light padding with fencing masks, the same kit we used with light weapons hand combat.
Bruce Bibee firstname.lastname@example.org
Author Norman E. Johnson responds. I read with much interest your comments on cocking the crossbow. Today's more powerful crossbows max out at under 200 pounds with the majority of them around 175 pounds. Unfortunately, those who most need the crossbow are the elderly and/ or disabled. Those who are able to cock a 175 pound crossbow with two hands on the string are indeed rare. I used to do it. As a Marine, I could put 100 pounds over my head with one hand.
Since then, as a bowhunter, I now need a crossbow, as most my age (82) do. Of the various cocking aids used, the rope cocking device, which reduces pull weight by half, is very popular. I know several women who can cock a 150-175 pound bow. A high percentage of bowhunters prefer to perch high above their targets on a fairly small stand. Here both the rope cocking aid and various cranking systems are very popular due to convenience and ease of use.
Proper use of the knees in cocking a crossbow with a belt-hook system would take a load off the back. But, a large number of those who really need a crossbow are lucky if they can even flex their knees, say nothing of cocking a crossbow in such a way, without the aid of the affordable leverage offered by the rope cocking aid or the nifty crank system. A rope cocking aid fits neatly into a pocket as well.
Would your scissors jack system actually be usable from a tree stand? Sure it could work. but I suspect it might be inconvenient. Safety is not to be overlooked either, particularly from high up in a tree stand. Cranks and rope cocking aids are almost a must up there. Any unnecessary contorting movements must be avoided.
Thus far, I have not heard of a 300-600 pound or higher crossbow. Frankly, such a powerful crossbow built on today's frame would virtually explode upon firing. I like seeing differing views on anything connected with hunting, shooting and gunsmithing. Your comments reflect that of a thinking person that we need more of.
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|Title Annotation:||READER FORUM|
|Date:||Jan 1, 2014|
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