How to build a Bungee Bazooka to shoot large homemade Nerf-type darts

The Project:

Always liked the smell of napalm and one of those boisterously robust American army bazookas in the morning? Then the DIY Bungee Bazooka (by Instructables user seamster) is just for you. Of course not as powerful as its canon firing cousin, this shoulder-mounted sling shot has the ability to shoot Nerf-type darts (along with apples and even raw eggs). At least you can have some 'harmless' fun with one of these beauts, and the multi-ammo launcher does pack a substantial punch, given its DIY nature. So without further ado, let us check out the very basic outlines for contriving one of them bazookas for ourselves (for details check Instructables).

Bungee Bazooka

Difficulty level: ChallengingTime required: No fixed time; as a matter of fact it depends upon your mechanical prowess.

Resources required:

1. 5 feet of 4" PVC sewer pipe.

2. A myriad of bolts including - two 5/16" (3" long) bolts, two 1/4" eye-bolts (2 1/2" long), nine 1/4" carriage bolts and two U bolts designed for 1" pipe.

3. Two pulleys - for rope sizes up to 3/8".

4. Washers (for all the types of bolts mentioned above).

5. Heavy duty key rings (with different sizes).

6. One 3/16", 48" long metal rod (around 24" could be needed).

7. Locking nuts and twenty flat head screws.

8. Two 3/16" quick links

9. Eight feet tubing along with a small amount of both hardwood and plywood.

10. Various types of adhesives along with craft foam.

For the dart and sling we would need foam tubes, webbings, craft foam, heavy duty wires, tennis balls and heavy fabric.

Instructions:

1. The first step will always encompass the determining of the whole layout and the access points (holes in this case) through the PVC tube for various components like the handle position. This can be done by a marking procedure along the circumference of the PVC tube. We can wrap a paper along the tube circumference, make the required marks (on the paper) and then re-wrap it for adding the marks on to the tube itself. To determine the access points, we can always divide the tube into specific quarters according to the paper markings.

2. Next comes the trigger handle, and it can be done (according to your preferred shape) by laminating three layers of 1/2" plywood (hollowed out in the middle). Though, we should take care that the handle has sufficient space to slide back to about 3/4".

3. Next comes the ammo ring holding pin, and this block can be created entirely from hardwood. The shape with two holes should have a smoothed rear slope, while the finished block (which is to be bolted by carriage bolts) should be 3 1/2" from the back end of the PVC pipe.

4. With the pin comes the release shuttle, and once again it is to be made form hardwood (preferably birch). The shuttle is to be fixed loosely (with bolts) in an access hole cut at the bottom of the PVC. The flexibility will make it slide backward when the trigger is pulled, thus releasing holding pin for the 'canon' to be fired.

5. The trigger mechanism itself is to be created by joining the hollowed out trigger handle to the marked PVC tube and then bolting the component at two ends. The front handle (for the placement of your left hand) can also be made from adequately shaped plywood and then bolted onto the PVC tube ergonomically.

6. Next comes the important component of the pulley system, and they are to be assembled from various pieces of hardwood and then affixed with glues and screws. The placement of the pulley is essential in determining the force created in the bungee cord.

7. The pulley brackets are now to be fixed at the front end of the tube, and this can be done by using flat-head screws. Though, a mini screw driver can be needed to get into the inside of the pipe for placing the screws.

8. Next comes the back end pulley system, and this can be created from two hollowed out circular pieces (with the holes corresponding to the diameter of the tube) of plywood glued together. They are to be attached with flathead screws.

9. Now comes the component required for the 'catapult tension'. We can use two 4-foot sections of blue thera-band for this, and they are to be wrapped over a key-ring and taped tightly in place. Two narrower pieces of tubes (resistance tubes) are to be attached to the main PVC tube by means of plywood wooden brackets. The protruding wooden components can now be embellished by using finishes such as brush-on polyurethane.

10. Finally coming to the darts, they can be made from a foam tube with a tennis ball on the rear end. Extending wires from the darts can be used to hook up the front key rings along the resistance tubes. A sling (for alternate ammos) can be made from a piece of heavy canvas along with webbings and fire hooks.

Frequently asked questions:

1. Can this PVC bazooka be made to fire alternate ammos (such as rolled up t-shirts)?

A. Physically it can be done, but with a different built of a sling.

2. Can one apply a paint job to the exterior PVC layer?

A. Yes, but it is recommended to sand the exposed PVC parts first, and use the right paint for the plastic components.

Quick tips:

We should also think about the safety factor, and thus two U shaped bolts (along the pulleys) are to be fixed, so that the recoil effect of the bands takes place in a parallel manner to the tube. Another safety measure is to attach two narrower pieces of tubes (resistance tubes, as mentioned above) that keeps the main PVC tube from deflecting.

Things to watch out for:

The above conception does tread the thin line between recreational shooting and dangerous shooting. Hence, one should take care about the material (which shouldn't be harmful or hard) of the projectiles used.