Tattoo Machines

A tattoo machine is a hand-held device generally used to create a tattoo, a permanent marking of the skin with ink. 

A Custom Tattoo Machine

Modern tattoo machines use alternating electromagnetic coils to move a needle bar up and down, driving pigment into the skin. Tattoo artists generally use the word "machine", or even "iron", to refer to their equipment, while amateurs and collectors often use the term "gun".

How It Works

Basically the machine works similar to alternating current- charge causes magnets to pull downward on the bar, which disconnects the circuit and allows the upward force of the spring to pull the bar upward

Power is conducted by wires in two different directions: Through the coils to the adjustable contact screw, and through the frame to the contact spring, via the armature spring. 

The tattoo machine parts

Current, flowing between the contact screw and the contact spring, completes the circuit, causing: 
The electromagnetic coils to pull down on the armature bar, which causes: 
The needle bar to move down with it, the needles at the end of the needle bar penetrate the skin. 
With the circuit broken, the armature spring is free to exert its upward force again, causing the circuit to close with the contact made again.

The basic machine was invented by Thomas Edison and patented in the United States in 1876 U.S. Patent 196,747 , Stencil-Pens. It was originally intended to be used as an engraving device, but in 1891, Samuel O'Reilly discovered that Edison's machine could be modified and used to introduce ink into the skin, and later patented a tube and needle system to provide an ink reservoir.

History

U.S Government patent for tattoo machine 1876

The technology used to make modern tattoo machines has come a long way since Samuel O'Reilly's inovations. While O'Reilly's machine was based on the rotary technology of Edison's engraving device, modern tattoo machines use electromagnets. The first machine based on this technology was a single coil machine patented by Thomas Riley of London, just twenty days after O'Reilly filed the patent for his rotary machine. For his machine, Riley placed a modified door bell assembly in a brass box. The modern two coil configuration was patented by Alfred Charles South, also of London. Because it was so heavy, a spring was often attached to the top of the machine and the ceiling to take most of the weight off the operator's hand.

Most modern tattoo machines can control needle depth, speed, and force of application, which has allowed tattooing to become a very precise art form. Such advancements in precision have also produced a style of facial tattooing that has attained mainstream popularity in America called dermapigmentation, or "permanent cosmetics".