Intro: Homemade Crossbow
I got this idea from a friend, and I used the basic body from his idea and modified the mechanism myself. It shoots a wooden barbecue skewer five to ten feet. When you make it, please send me a picture. I used a recycled plank that was a bleacher from a high school gym.
Step 1: Parts
Here are the parts/things you need.
-chop saw (or hand tools)
-coping saw (hand tool)
-cable staples (those thinges that are like staples that go on cable
-long bolt with nut on the end
Step 2: The Stock, and the Guide
I suggest that you use a 2x4 piece of wood for the stock. There really isn't much to tell you except that you should know, all you have to do is to trace the shape of the stock on the piece of wood as well as making a V notch, and cut it out with a jigsaw. Mine is a 17" piece of wood and I put the center of the notch at the 9" mark from the front of the stock.
To make the guide I used 3 cable staples centered in the middle of the stock 1", 2", and 5" mark from the front of the stock.
This is mine:
Step 3: The Trigger Mechanism
The trigger mechanism is a little tricker then the other steps, but still kinda easy. the trigger mechanism is about 3" long (from top to bottom). the trigger is pointed on one end to fit the notch. the side supports are about 2" long and 1 1/2" wide, I used 1/4" thick molding. we used a 5/16" bit, but just make sure that the bolt is a little smaller than the hole in the trigger. the trigger should be able to pivot on the bolt. Drill two small holes near the bottom of each support where you will screw the supports to the stock later.
To place the trigger mechanism, assemble it by placing the trigger between the two supports and threading the bolt through the two supports and the trigger. Place the supports close enough to the notch, and high enough on the stock in order to allow the trigger to pivot freely, with the pointed end of the trigger resting in the bottom of the notch. mark the location of the supports with a pencil, then drill through the existing holes in the supports into the stock. attach the supports on the stock with screws
I wanted to prevent the trigger from releasing accidentally (and potentially hurting my older brother =) LOL), so I wrapped two long rubber bands around the front of the trigger supports to the back end of the stock. This holds the trigger down until I press down on the end.
Step 4: The Arm
I made the arm from a piece of wood that is approx. 3 1/2" wide, 14 1/2" long, and 3/4" thick. I traced the shape of the arm on that piece of wood. you want the middle of the arm to be the widest part (mine was 1 1/8" in the middle and 5/8" at the ends). Trace the end of the stock 1/2" into the middle of the arm and use a coping saw to cut it out.
Drill a small hole near each end of the arm, where you will insert the small eye screws. Insert the stock into the arm so the top edge of the arm is flush with the top of the stock. I wanted a sturdy crossbow so I drilled two holes in the front edge of the arm and into the stock so I could screw the two pieces together, but you could use nails instead.
Tie a length of sports rubber between the two eye screws and adjust for the proper tension.
Step 5: Shooting
To "cock" the crossbow, press down on the back end of the trigger and hook the sports rubber around the pointed end of the trigger. Let the trigger down into the notch while holding the sports rubber in place. Slide a wooden barbecue skewer through the cable stables so the sharp end is pointing forward (duh, but it had to be said), and the dull end is just in front of the notch.
Tips for shooting
If the back end of the skewer is too close to the notch, the sports rubber will go up under the skewer, and if the skewer is too far forward, the sports rubber might snap too high and miss it.
Keep the crossbow level otherwise the skewer will slide one way or the other.
Don't point it at older brothers (or anyone else), or dry wall that you don't want holes in.