Primitive Archer
Main Discussion Area => Bows => Topic started by: Bikewer on July 04, 2007, 12:45:43 pm
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Prod, actually... ;D
Anyway, I've started work on this crossbow project, and have progressed to this point on the bow:
(http://i192.photobucket.com/albums/z156/Bikewer/4thofJuly002.jpg?t=1183561945)
and:
(http://i192.photobucket.com/albums/z156/Bikewer/4thofJuly003.jpg?t=1183561994)
This is the last of the red-oak board I've already used for two bows. It's 30", with peg nocks. Silk backing (necktie) for safety....
I don't want this thing letting go when I'm holding it in firing position!
I figure I have to get the bow working before I can do anything else; as the stock will have to be tailored to the draw length and all.
I have all my other materials assembled, including a piece of 1 1/2" aluminum rod stock for the "nut". (plan to use hacksaw and dremel)
So far so good....Short bows are really, really stiff! Trying to brace this little dude is a major pain. I'm planning to use a draw length that's pretty short, hopefully the thing will hang together.
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Pretty neat stuff. I remember trying to make one as a kid. I couldn't do it. What is the "nut"? I know. It's the guy asking all these dumb questions. More details and pics would be appreciated. Jawge
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Here's a pretty good illustration of a design similar to what I'll be using:
(http://www.crossbowhunters.com/userfiles/rollernut_pattern_crossbowbuild_part_2_pic_4.jpg)
The nut (traditionally made of antler or ivory, I understand) holds the string at full cock, and the bolt in alignment. It's released by a trigger very much the same as a typical revolver trigger works.
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I have just made the nut from dense wood and oriented the grain vertically. The trigger can be cut from a piece of wood shaped like a goose head and neck. The 'beak' catches the lower lip on the nut and a rotating pin goes through the 'eye'. The neck forms the trigger. I usually use four pieces of wood for the stock. Two outer pieces and a central spacer with a gap left for the trigger and nut to fit in. That makes it easier than trying to cut the hole that houses the mechanism.
By fitting a spring behind the trigger you can make it click into a cocked position by rotating the nut back with your thumb.
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I have seen nuts made from hardwood, and it would probably suffice for this rather-light weapon. However, some of the crossbow sites complain of splitting....
For this one, I'll use a design where the nut is actually held by steel flat-stock sidepeices, screwed onto each side of the stock. There are a lot of examples of similar designs, some using pieces of hardwood instead of steel.
My thought is eventually I'll be able to upgrade if I want to.
A couple of nylon (oops, not very traditional... ;D) washers on each side of the nut.
When I was stationed in Germany back in the 60s, the local (Wurzburg) museum had a wonderful collection of medieval weapons. Many of the crossbows were fantastically engraved and inlaid with silver and ivory; obviously not meant for a peasant!
Many of the bolts were very heavy, sort of bottle-shaped with thick center sections meant to add mass for armor-piercing.
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I've never really gotten exactly how the trigger/nut thing works, could you explain?
Sean
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How about a simple lever ... with a notch???
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Ever look at the innards of a revolver? When the hammer is at full cock, the trigger engages a small notch on the hammer assembly. That's what keeps it from flying forward. When you pull the trigger, it comes out of engagement with the notch, and the hammer falls.
Same principal (actually, I imagine firearms borrowed the principal from crossbows!) here. The nut, at full cock, holds the bowstring around the two little uprights, and the bolt or arrow lies between them, in contact with the string. When you pull the trigger, the whole assembly is free to pivot forward, and off she goes.
Here's a slightly better illustration:
(http://198.144.2.125/Crossbows/Full/mech2.jpg)
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Aha! it all makes sense now! :) Thanks for the explaination, now I might want to build one.
Sean