I’ve probably forgotten important parts by making it simple, so if you’re actually considering following this guide then make sure to read it all in advance and try to understand it. If you find issues or questions, drop me a line.
me Posted:
SIMPLE COIL GUN HOW-TO
Materials:
– Brbum or plastic tubes with ¼” inner diameter (pens work, too)
– Magnet Wire (Radioshack, ebay, motors, old wall warts) (22-26 AWG depending on capacitors)
– Camera Flash (disposable camera or removeable flash [best])
– Cyanoacrylate glue (krazy glue, dollar store instant glue)
– If you’re using hobby tubes for the barrel, get a short piece of ¼” rod, or a bolt that will fit snugly in the tube.
– Heavy gauge insulated wire (<24 AWG)
– Soldering tools
– ¼ inch Steel pellets for Slingshots
– Dremel tool (or any rotary tool with a cutting blade)
– Optional:
o Ferrous washers
o Handmade steel slugs
o Project box
Basic Knowledge:
A coil gun uses a pulse of high voltage, high current electricity to induce a large magnetic field in the coil surrounding the barrel. The magnetic (typically ferrous AKA iron) projectile is sucked into the magnetic field at high speed. By the time the projectile is half way through the coil the electrical pulse has stopped and the projectile continues uninterrupted out of the barrel. Typically coil guns use capacitors to store the energy and release it very quickly.
CONSTRUCTION:
1. Disbumemble the flash. All you need is the PCB, capacitor, and flash bulb
2. Replace the wires connecting the flash and capacitor with higher gauge ones. You want the least resistance possible outside of the coil.
3. Wrap your coil:
For non-pen barrels:
a. Using a Dremel, cut a 1” slit into an end of the barrel. This is for air to come in and so you can see into the barrel for positioning the shot.
b. If you have washers that fit snugly onto the tube, use them as they will make winding WAY easier. I use quarters with a hole drilled in the center. One washer goes right on the end of the cutout slit. Glue it on with Krazy glue; once that dried, use hot glue as well to keep it from breaking off while winding the coil.
c. Put an end of the copper magnet wire through the other washer. This is so the coil can be wrapped easily. You need to cut/grind/file a little notch or hole for the wire to fit in.
d. Glue the second washer one inch away from the first one. Use the krazy glue to bond it on at first, the n dump hot glue on the end to keep it from breaking.
e. When wrapping the coil, attach the barrel to a drill to make it easy to spin it. Simply spin the barrel and wind the magnet wire on as tightly as possible. It will slip and be imperfect during the process. Unless you have a coiling machine, you won’t get perfect flat turns. Just make it as close as possible.
f. If using radioshack wire, just get the whole spool onto the coil. Otherwise coil until it’s about an inch in diameter. Leave at least 2 inches of wire extra on either end.
g. Once the coil is done, drip Krazy glue over the coil especially where the wire leaves the coil. Cover it in tape and leave it somewhere to dry for a while.
h. Plus the end of the barrel with a bit of rod/bolt. Drop a steel shot into the barrel and position the rod such that the steel ball is half covered by the washer. Glue the end plug in place.
For pen tubes, Position the rear washer such that a steelshot is ½ covered by the washer. Follow the previous steps for coiling.
4. Strip the ends of the coil wire (use a bit of sandpaper to pull of the enamel) and solder some thicker insulated wire to them. Cover the soldered bits with tape or shrinkwrap so you don’t get shorts or electrocutions.
5. Unsolder one lead from the flash bulb. Splice in the wires from the coil. That is, connect one wire from the coil to the flash bulb, and the wire from the capacitor to the other coil wire. This uses the flash as a trigger. Put the bulb in a film canister if you don’t like being blinded every time you fire. Do NOT cover the bulb in tape. It won’t work. The tape will conduct the high voltage pulse that ignites the flash. If your flash had two xenon bulbs (the second is a small normal bulb with a metal ring around it), use whichever bulb has thicker metal leads.
6. If you have a small magnet handy, tape or glue it to the back end of the barrel to hold the shot in place. Not needed, but makes it easier to point the barrel.
7. Apply batteries to the charge circuit and hit any switches that may be needed to get it charging. When the ready light comes on, load a shot and point away from eyeballs and fire.
How to make a simple coilgun: A guide written by me
