Primitive Archer
Main Discussion Area => Bows => Topic started by: Brent.Mac. on November 02, 2011, 10:18:04 pm
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Hello once again PA
Sometime in the near future I'd like to make a crossbow. If anyone has ever made one I can't really think of a simple trigger, without gears and such (metal) So trigger designs would be awesome! ;D Also the size of bolts.
I was thinking of making the 'bow' part out of a hickory board if I can get my hands on one, or the other half of my friends stave if he doesn't want to use it=D.
So would a board bow work? How long the the bow be around maybe 30"?
Has anyone ever tried using the "hair" from corn to back a bow? :-\ If so how did it turn out? Just sorta came to mind :)
Thanks again in advance!!
Brent
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for a trigger, what you could do is cut a small shelf into the stock, and drill a hole in which you would put a dowel to push the string off of the shelf
good luck
noel
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corn silk is not strong at all. I wouldn't bother with it. JMHO. Josh
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Brent, like Gun Doc said, don't waste your time with corn silk. But speaking of silk, just go to a few thrift stores, and look at the tie section, and find some 100% silk ties, and you even have a pattern or design. Silk scarves, can be had cheap also. Raw hide from a big chew toy from a pet store, and thinned down, and cut to size, also is an idea. ;) You can also paint, or stain your backing.
Wayne
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Yea I didn't think corn silk would work lol ::)
But that trigger sounds really simple, easy to do :laugh:
Would you guys reccomend backing the bow? Used for a crossbow, seeing how it has to hold so much weight.
When you back with silk, what kind of glue do you use?
Thanks again guys
-Brent
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If the grain is good enough there is no need to back hickory - it's about as tough as any other wood - but the grain MUST be straight.
Titebond 3 will work fine as would hide glue/gelatin.
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The only reason I backed my primitive crossbow prod was that when it held to the shoulder the bow is level with your face.
I'm ugly enough already, but the thought of a bow limb coming back and smacking me in the eye didn't appeal. I was working with a wood I hadn't used before and it had a few knots and minor cracks... better safe than sorry. I also knew I'd be letting others try it.
Rawhide is good, or you could wrap a spiral of strong thread (linen? Dacron) around the limbs just to help constrain them in event of failure.
The old style high tensile aluminium alloy prods had a reputation for breakage and would be bound with pvc tape for safety.
I've updated my Primitive Crossbow thread with some extra dimensions.
Here's a pic of how I sketched it out on the stock, hope this helps
(http://i411.photobucket.com/albums/pp195/Del_the_Cat/Website%20stills/PXbowlayout.jpg)
Del
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Brent.Mac it would help you to check out Del's crossbow thread. He really knows what
he's doing.
Lane
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Thanks guys, I guess I better back it, with silk or rawhide if I can get any, maybe then strong thread (so it looks cool ;))
So when backing is it generally better to use more glue then less? Or other way around.
Brent
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Depends on the glue, as a general rule less is best. With hide glue I actually put the wet rawhide into the glue pot and then pulled it out through my fingers to get off the excess.
Actually excess is a good word, you want to make sure the surfaces are thorougly wetted but you don't want excess. The temporary string binding to hold on the rawhide helps to squeeze out any excess.
Del
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One of the simplest crossbows I ever saw came out of Viet Nam. A fellow student's older family member served there and brought it back. The stock was a tapered stick, heavier at the bow end with a square hole to accept the bow. The bow was a simple narrow longbow, somewhere between 40 and 48" long, with a D cross section, except for the handle, which had a square cross section that faded into the D cross section. I assume the shooter carried some sort of stringing device, although we were able to push/pull string it. It just looked awkward. There was a narrow trough along the top of the stock, with a groove for the string to catch into. If you looked down from the top, there was a mortise under the string groove. In the mortise was an L shaped rocker trigger held in with a pin. Picture an upside down L when looking at the stock from the side. The base of the upside down L was even with the bottom of the string groove. Pull back on the leg that was hanging out the bottom and the base of the upside down L pushes the string out of the groove. The bolts were bamboo. They were just like shorter thinner bamboo shafts that we would make. The nodes were sanded down smooth. The business end was sharpened and the nock end was plugged with bone or something. They were set up with the smaller end forward. No fletching, but accurate as all get out, up to 30 yards. Whoever made it did a great job. It was almost silent! Made no more noise than if you pulled back the string of your bow 1 inch and let go! You could take it down in seconds and roll it all up in a cloth or mat.
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Tom;
Another variation of that trigger, was a trigger slot cut through, behind the string notch, and a double ended "T" was made, and turned sideways, and inserted into the slot, and then turned around, and one end of the "T" faced flat against the string notch, and string put on the "T", and when the bottom "T" was pulled, it raised the string up and off the notch. The (Montnard(SP?), and other mountain tribes made them. Some bows were tied on.
Wayne