It's been a while since I wanted to make a rubber gun. I have so many rubber bands at my office and also at home. Nowadays makers are making (machine) guns that hold multiple rubber bands which are cool but more complicated in designing its trigger. I want to make a simple one, as a gift to my kids on Christmas. It was one week researching and thinking of the mechanical parts and one week crafting in my spare time and got it done just in time, on December 24th.
It started when the SCI-FI Contest rolling out. I have some Rogue One characters cards laying on my desk and my kids love Captain Cassian Andor's Blaster so much at the first time they saw the Nerf version. Well, I just tried to present them a gift on holidays and this is it. It is far from the beautiful finishing of ClenseYourPallet's Pallet Rubber Band Gun or eggfooyoung's Laser Cut M-6 Carnifex Rubber Band Gun from Mass Effect laser cut gun. It is leeroystake's Rubber Band Gun Toy (ply Board) that encouraged me to start working with the plywood that is laying around in my garage. When you cannot build a beautiful one, start with a functional one and upgrade later. Practice makes better, but you get nothing if you never started one.
ClenseYourPallet made one piece trigger. Leeroystake made a two pieces mechanical trigger. Eggfooyoung got a four pieces mechanical trigger. I want to make it as simple as possible, but one piece doesn't hold the rubber band well. If you pick a stronger spring you need larger power to pull the trigger and that is not good for my kids' tiny fingers. Two pieces trigger is good, but Cassian Blaster trigger moves horizontally unlike the classic pistol trigger. I try number "three" to fix the rubber holding and horizontal trigger while "four" is too much for the limited space in my small gun.
Step 1: Materials and Tools
- 45 cm x 30 cm of 4 mm plywood (outer boards).
- 25 cm x 15 cm of 7 mm plywood (middle board).
- Bamboo chopsticks.
- Some small screws.
- A nail with 2 mm in diameter.
- A tension spring (compression spring as alternative).
- A paperclip.
- A drill.
- 5 mm drill bit.
- 1 mm drill bit.
- 310 mm hole saw with 6 mm pilot drill bit.
- A jigsaw.
- Some files.
- Spray paint (black doff, clear coat is optional).
- Gold pen marker.
- Wood glue.
Step 2: Design
I drew the design with vector app. This toy is not designed in a very accurate measurement. Instead of cutting the model and draw on its edges, I present you an unusual way of transferring the printed image to the board. I laid my paper on the board and I made holes on every corners with a pen tip. Then marked the holes on the board and connected the dot markings on the board. Will this method saves some time? Try it to find out :D
The blue line (also the green, mixed with the yellow line) represent the outer boards. Cut two identical boards based on this blue line.
The yellow lines (splitted into two parts) are the center boards. The front part is including the magazine and the sight that holds the rubber band at one side. The rear part is the hand grip center part.
The red lines are the mechanical parts also positioned in the middle. The red dash lines are showing the parts positions when the trigger is pulled.
The orange line is the part holding the trigger. The front part is clipping and glued to the front center part of the gun. The rear part is sitting on the rear center part of the gun.
The rubber band holder is cut with a 310 mm hole saw with 6 mm drill bit. Then I removed the four sides with a jigsaw. You can see that it is different from the initial design but straight cuts saved much time and it holds the rubber in the same way.
Step 3: Pivots
There are two pivots I use in the mechanical parts. The center part of rubber band holder is already drilled with 6 mm hole when we cut a circle with the hole saw. I use bamboo chopstick as the pivot/dowel as it is measured 5 mm so I have 0.5 mm surrounding to let the rubber band holder moves freely. Use a 5 mm drill bit and drill on the outer boards half way down (about 2 mm) and plug in the chopstick dowel.
I use a rectangular piece of board to hold/stop the rubber band holder. This piece of board needs a pivot too because it has to release the rubber band holder in order to shoot. I was thinking of using the same chopstick as the pivot, but drilling a 6 mm hole on a 8 mm board in width will make it breaks easily. Then I use a 2 mm nail instead.
Always remember to give the mechanical parts a test to make sure everything goes well. When the trigger is pressed, the rectangular board is in diagonal position releasing the rubber band holder to make a circular movement.
You should read the next step (Retract) before you drill your pivots because the part you have in hand (spring) may affect the position of your mechanical parts.
Step 4: Retract
After releasing the rubber band holder, I have to retract the rectangular piece to its position stopping the rubber band holder and to push back the trigger to make another shoot. Here I need a tension spring which I have several from tearing down old printers. Get the appropriate size or you can reposition your mechanical parts to fit the spring in. If you cannot find any tension spring, a compression spring from a retractable pen can be used, but you should place it at the lower part instead, behind the trigger (take a look at the notes on the photo above).
It took some time to think of a way to hold the spring. I used a paperclip. Cut appropriate length in the shape of "S" in 90 degrees rotation (or let's say an infinity symbol ∞). First, bend one end and drill the long side through the board. Plywood is soft and this can be done slowly. Use pliers and push it in millimeter by millimeter. After it get through the board, bend the pointy end toward the board, hold it with pliers at the position where the paperclip comes out from the board and slowly hammer the pointy end into the board. Do the same to the other side of the spring on the rear middle board.
Step 5: Glue
Now glue the front middle board to the back board (the right side outer board) because this is non-moving parts. Leave it for a while to dry.
Step 6: Screws
Get some screws with the length of 6 to 10 mm, so that they bite the outer board and the middle board. Again, I got mine from the old printers. Why screws and not glue? I screwed the top board (left side outer board) so that I can fix if the mechanical parts are broken or jammed. So is the middle rear part, because it is holding the spring, in case the paperclip get loose or the spring is broken.
Join the back board (right side outer board) and the rear middle board with some screws. Place in the mechanical parts. Give it a test to make sure the mechanical parts are working good.
Now join the top board (left side outer board) with some other screws. Give it another test. If your rubber band holder is not moving when the trigger is pulled, then change its dowel with a longer piece of chopstick so that it has a little space between the walls (the outer boards) and let the rubber band holder spins freely.
Step 7: Finishing
Sand it. I removed all the sharp edges with files. Then I painted it black. I have no time to do the detailing with add on wood, so I simply use a golden pen and draw on the black doff paint. Give it some time to dry. Different sizes of rubber band will vary the speed and power of destruction. Pick the size that suits your gun.
Step 8: Targets
I have Star Wars character cards which I got from certain purchase at local retailer store last month. I used old name cards to make the stands. It is 4 cm x 2 cm rectangle with a 0.5 cm x 1 cm rectangle in it. Cut the line and fold the dashes. Position the cardboard one or two millimeters from the bottom of the target card, aligned vertically. Glue one side of the large rectangle on the character card (do not glue the small rectangle). The last photo is revision of my first design, a better stand :)
Enjoy the shooting game. These standing targets can be flatten and easy to carry on holidays.
Step 9: Let the Game Begin
The kids are happy with the new toy. Different styles of shooting will bring smile on your face. I always warn them not to point at someone but the targets. Always keep an eye on them while playing. Happy holidays! ^^