Introduction: Pocket Sized Coil Gun
Step 1: Gathering Materials and Tools
-Empty pack of gum
-1/8 Tube ( old pen tubes work great!)
-Normally Open Button switch
Step 2: Making the Frame
I put a frame into the gum pack to give it some extra strength and make it easier to pack everything in the small space. Basically, I measured the gum packs dimensions and cut out some sheet acrylic to the correct measurements and super glued it all together. Once your frame is complete, move on to the coil.
Step 3: The Coil
To make the coil you will need a small tube, an ink tube from a pen works well. Simply clean the tube with a q-tip and and start wrapping your coils.
Once you have your tube ready, tie a half knot with the wire onto the tube and super glue it in place. The position of the knot should be about 1 inch from the end of the tube. Now start wrapping the wire around and around the tube toward the other end. Try to get a nice tight fitting coil, and keep wrapping until it is about 3/4 in. long, then apply a coating of super glue to the coil. Now you have completed the first layer! I found that 7 layers works pretty good for this compact coil gun. To make another layer, simply start winding the wire back to the knot where you first began. Keep winding until you have about 7 layers, remember to glue each layer as well. This takes some time so don't try to hurry it because the coil is one of the most important parts of the gun.
*Important Note* Do not change the direction you wind the coil, exp. if you start winding clock-wise do not switch to counter-clock-wise.
Step 4: Making the Curcuit
Once the frame is made, you can begin making the circuit. This will allow you to build the circuit into the frame so it is easier to fit everything together. I de-soldered the capacitor and the + and - leads, then shaved the circuit board down as much as possible so I could make room for everything else. Now lay down everything into your frame and find a way to make it all fit (see my picture above of how I did it) then start wiring it together.
Your circuit might have a push button switch on the circuit board to charge it, I just soldered the switch closed and put a switch onto the positive lead to the battery. this switch is now the charging switch.
Now solder the capacitors or capacitor in parallel back onto the circuit.
Once your coil is made solder one of the leads to the negative lead of the capacitor bank and the other to the positive, but wire in a push button switch. this will be the firing switch.
Now re-pack everything into the frame and glue the switches on the edge of the frame so that you can operate them from the outside.
Step 5: Fitting It Together
Once your circuit is finished and glued into the frame, slide it into the gum pack and cut holes for the two switches, the barrel, and the charging light. I sharpied the holes black so they would be less noticeable.
Step 6: Ammo
Now grind down your nail to the appropriate length (diagram above shows the correct proportions of the ammunition) and either round off the tip or give it a nice point. My nail was still a bit to big in diameter so I used my dremel and sanded it down a little. You will want your "bullet" to slide down the barrel easily.
Step 7: Fire!
Now you should be ready to fire! Simply switch the charging switch on, and once the red light flashes, turn the charging switch off. Then insert your projectile down the barrel and push the button switch. Have fun!
Please ask if you have questions
Runner Up in the