C:\> Rostislav Persion's Projects

.:: Thompson Gyro Coil Gun ::.
Gyro Induction Gun Concept

I got this idea from seeing a display at a local science museum.

This is based on my original project post from 2003....



A coil wrapped around a ferrous core with rising current in it will repel a conductive ring that is around the same core.

I decided it would be cool to scale this up and create a projectile accelerator. It also happens that the shape of the projectile has great aerodynamics. Another idea is to spin the ring before launching it, in order to add stability.

I like this better than a standard coil gun because there is no power limit and no tuning except coil turns... The limit is the ring exploding or deforming.


These rendered views illustrate the simplified concept and design of the gyro gun. You can see the motor that rotates an iron core which rotates the aluminum projectile which slides on to it. The coil which is pulsed is on a coil form which allows the core to spin within it freely. Once the coil is pulsed, the projectile is forced off the core at high speeds as it travels straight in a stable low air resistance flight.


Side view of the core with a coil around it. The projectile is slid down the core until it touches the double layered coil.

These are the copper projectiles that are fired from the core. Copper is relatively light and a good conductor. The rings are made from copper pipe and are cut a length that is about the same as its diameter. If the rings are cut too long then gyroscopic stability is lost.

The power supply charges the capacitor bank up to 5kV. The capacitors are rated for 4kV so usually a voltage of no more than 3.5kV was provided.

The capacitor bank consists of two 32uF 4kV pulse capacitors. Together they form a 64uF 4kV bank with a maximum storage of 512J. For this experiment they were charged no more than 390J.

This is an idea for the future gyro gun. Two gyros can be shot at the same time using the same pulse. There will be better coupling as well.


The projectile dug into the foam board and penetrated deeply.

The projectile easily pierces a sheet of card board.

The projectile blasts its way through the light bulb leaving it intact yet making two holes as it goes through. A point of entrance and a smaller exit hole.