Coil vs. Rotary Tattoo Machines How Rotary Tattoo Machines WorkRotary and coil tattoo machines operate in two different ways to achieve the same goal of inserting ink beneath the surface of the skin (i.e. epidermis) and depositing it into the secondary layer of skin, called the dermis. On a rotary tattoo machine, the needle bar is attached to a nub on top of a cylindrical motor that spins clockwise, moving the needle bar back and forth in a linear fashion as the motor rotates (see image to right).
That motion inserts tattoo needles into the skin and retracts them smoothly, in a series of constant, fluid motions. Coil tattoo machines work quite differently, in a much more complicated fashion. They utilize electromagnetic current to create and break a circuit in a cyclical fashion, moving the needles attached to the machine forward into the skin when the circuit is created and retracting them when the circuit breaks.
When power is delivered to a coil tattoo machine, the two coils are charged and turned into an electromagnet (see image below). The electromagnet created by the coils pulls the machine’s armature bar down towards the coils, which subsequently forces the attached tattoo needles down and into the skin. The downward motion of the armature bar pulls the front spring down with it and causes the spring to disconnect from the contact screw above it that a second before had completed a circuit.
How Coil Tattoo Machines WorkThat break in the circuit causes the electromagnetic field to collapse momentarily, releasing the armature bar from the coils. The spring attached to the armature bar wants to move back to its natural position, and it pulls the armature bar up with it. When the front spring reconnects with the contact screw, the circuit and electromagnetic field are re-established. That starts the process all over again, pulling the armature bar back down, forcing the attached needles into the skin, pulling the front spring away from the contact screw, and breaking the circuit once more.
The way a coil machine is powered creates a hammer-like effect that drives tattoo needles into the skin more forcefully than they’d be moved by a rotary motor. There’s constant power delivered to a rotary motor that keeps it moving in a fluid, clockwise pattern, pushing needles into the skin and pulling them back out more smoothly. Rotary tattoo machines therefore tend to be gentler on the skin, and tattoos created with rotary tattoo machines often heal faster and with less scarring–particularly when inked by novice tattoo artists.
That said, if you love the buzz of tattoo machines that’s traditionally associated with tattoo shops, then a coil tattoo machine is the option for you–particularly if you’re an experienced artist who can manage a coil machine with finesse. Rotary machines are incredibly quiet by comparison, and there are fewer moving parts involved, which means they’re typically more low-maintenance than traditional coil machines.