Introduction: Rubber Band Gun With a Working Hair Trigger - Made From Cardboard
This is a really easy and fun way to make a rubber band shooter. This is not your standard slip-it-off-with-your-finger gun, but a toy with a real mechanical trigger/release mechanism that works and feels like it should. The mechanism even allows the gun to be cocked with just your thumb.
It is made from the cheapest possible materials:
- Corrugated cardboard
- 1 toothpick
- 1 popsicle stick
- Paper or wood glue
Tools you will need:
- A box cutter
- Something to make holes with (e.g., a Dremel tool, a drill, or even a pocket knife)
- About 30 minutes, give or take - depends on glue drying time.
Step 1: Cut and Laminate Cardboard Sheets
Standard boxes from Amazon.com will work fine - just get yourself 5 to 7 pieces of cardboard, about 8 inches long and 4 inches high, and glue them all together. The size of the gun is something you can fiddle with - I chose 8 inches because that made the tension on standard postal rubber bands about what I wanted it to be, and we have a billion of those lying around from all of the junk mail we receive.
I used Gorilla wood glue for this because that's what I had at hand, but Elmer's or any other paper or wood glue should work just fine. While you are waiting for that to dry (typically 20-30 minutes - stick it under a book or something), you can make the trigger mechanism.
Step 2: Cut the Trigger and Release Out of a Popsicle Stick
The trigger mechanism is made of two parts: the trigger and the release. The release is responsible for holding (and letting go of) the rubber band, and the trigger is set up to unlock it when you pull on it. The release also cocks to reset the gun and put the trigger back into position for shooting.
To prepare the release, start by cutting a concave shape out of the end of the popsicle stick, as shown. This is where the rubber band will sit when the gun is loaded. This can be done with a box cutter (be extremely careful - cutting wood with a box cutter, particularly a round cut like this, can result in awful, horrible, nasty, bloody injury because it is prone to slip off the material), or you can more safely approach it with something like a small drum sander in a Dremel tool. Or a round file. There are multiple ways to do it.
When done, cut the popsicle stick about 2/5 of the way toward the other end. The larger piece will be the trigger. In it you will cut a notch as shown in the picture. A box cutter works great for this as long as you cut against the grain first - otherwise you will split your stick. The notch can and probably should be larger than what you see in the picture, though (and indeed this one was enlarged a bit before the build was completed).
Inside the cardboard gun, these two pieces will meet as shown. The release is kept from pivoting upwards by the trigger, which allows the rubber band to be held into place. When the trigger is pulled, the release is pulled upward by the rubber band and it lets it go. This will hopefully become clearer in the next step.
Step 3: Mark and Cut the Cardboard
This is where you get to be creative with the shape of the gun. Lay the trigger mechanism atop the cardboard as shown (it is probably dry enough now to manipulate) and make sure that there is room for the release to have a pivot hole below the top edge of the gun. Then place the trigger roughly as shown and draw a gun around it. You can then cut it out with the box cutter.
It is not critical that the angles be exactly as indicated. The main thing is that the release should be positioned such that the bottom of its back can rest on the top edge of the cardboard, and the point above the midpoint can be completely below it.
Drill or carve a hole in the midpoint of the release that will allow your toothpick to pass through easily, as demonstrated. Then mark the cardboard and make a smaller hole all the way through the cardboard. The toothpick should be tight in that hole, so make sure it is small enough to hold it in place once inserted.
Step 4: Attach the Release Pivot
To attach the release, you first need to dig out some of the cardboard. As depicted here, the paper is removed from the middle of the thin cardboard in the center of the gun. Remove enough so that the release can pivot freely from the angle shown to straight upright.
I used the trigger (the notched end was easiest) to dig out the paper. It does not require any special tools for most cardboard - you can just compress and rip out bits of paper a little bit at a time until there is room for the mechanism.
Once there is room in the middle of the cardboard, hold it and the release up to the light, line up the holes, and jam the toothpick through the assembly so that the point is just beyond the other side. Then break off both ends of it. Congratulations, you have a working release!
Step 5: Attach the Trigger and Complete the Build
Trigger insertion is the most critical step. Push the trigger through in front of the release so that it sticks out the bottom. I pushed mine through from the top so that it would clear the cardboard center out of the way without disturbing the release, and so that it made room in front of the release. You will need that room for the trigger to pivot out of the way of the release when you shoot.
Once in place, look inside from the top and make sure that the release sits in the notch of the trigger. The picture shows a trigger/release pair sitting above the gun to demonstrate what it should look like inside.
With the trigger in place, mark the cardboard and drill a hole through the cardboard and trigger. Use the smaller bit for this. If you are not using a drill, you might need to take the trigger out, make the small hole with a nail or something, then carefully make a larger hole in the wooden trigger. Either way, the trigger hole should again allow the toothpick to pass freely through it, while the cardboard hole should be tight around the toothpick.
Once everything is drilled and lined up, jam in the remainder of the toothpick, break off the ends, and attach rubber bands.
The lower rubber band is technically optional, but it is easier to consistently get the gun loaded with it there: it makes it possible to just cock by pulling the release back with your thumb. This pushes the trigger out of the way until it clicks into the notch.
The top rubber band goes from the front of the gun to the back of the release. When loaded, just pull the trigger and watch it fly. Congratulations, you've made a cheap and unique rubber band gun that your kids will love!