Coil Gun

Overview

This is a guide to create a functioning coilgun. The purpose of the gun is to accelerate a projectile at high speed. The gun consists of coil wire to perform as a electromagnet which serves as a type of motor to shoot the intended small object. The coils receive charge from the capacitor to shoot the object, and turns on in a timely sequence so that the object moves out of the gun(in our project’s case, a straw). The end result will be able to shoot a small ferrous object a few feet. CAUTION: We are not responsible for any injuries as a result of this project guide.

Materials:

Multimeter- Used to measure the voltage on the battery and on the capacitor to make sure that the capacitor charged each time we tested it

Capacitor- The capacitor took in the voltage from the battery so that it can charge to shoot the object inside the straw. (This can be obtained in a variety of ways such as purchasing one, making your own, or by disassembling a disposable camera.)

Battery- Used two batteries, gave the capacitor charge, contained 9 V each battery (18 V total) Alligator clips- We used two alligator clips to connect the objects for charge

Straw- the “gun” itself; shot the objects inside

Magnets- the objects that were shot inside the straw Copper wire with insulation outside- the wire outside the straw, also known as the the electric magnet

Pencil- used to wrap the wire

Meter stick- measures the distance of the objects

Physics Explanation
In essence what we did was make an electro magnet. However by using a capacitor to send a large charge through the wire in a brief amount of time instead of a constant charge we create an magnetic field for a brief instance. The projectile then becomes magnetized and is attracted to the loop magnetic field. The ferrous object is given enough kinetic energy to propel itself for a distance that is determined by many factors such as amount of charge on capacitor or length of wire/ how tightly its wound. Once the projectile is completely enclosed by the coil, the current through the loop is turned off so that the speed does not slow down.

Test Results
Part of a paper clip: It made a huge spark and traveled the table, exceeding a meter in distance. The velocity it was shot at exceeded our expectations, fired off the table. We couldn’t find the object afterwards.

Nail: Also made a spark, traveled almost 1 meter in distance. The spark was not as big as with the part of a paper clip.

Take the coil wire and wrap it tightly around the pencil about two inches. The wire should be very close to each other.

Once that is done, slip off the wire from the pencil and onto the straw. (make sure to strip the two ends and leave them accessible).

Connect the battery in series and attach to the capacitor with alligator clips to charge.

Use the multimeter to determine whether or not the capacitor has reached about 18 volts. Once it is completely charged, disconnect from the batteries.

Clip off a small piece from a paper clip and place it inside the straw

Connect the capacitor to the wire coiled around the straw and fire.(careful there may be a spark)