HOW DOES A MODERN TATTOO MACHINE WORK?

The tattoo machine ('gun' is a misnomer) is really a basic doorbell
circuit (you know--you push a button and somewhere in the kitchen this
little arm bangs the hell out of a bell thingie). For you techies out
there it's a DC coil and spring point(s) machine. Both doorbell and tat
machine were invented before household current was available.

 

It is essentially in 3 sections: The base, the mechanism, and the
sanitary tube. The base really is the bulk of the metal; a rabbit ear
with a screw in it, bent at 90 degrees to hold coils. In the front
there's a round hole to hold the sanitary tube.

Some people think the base looks like the handle of a gun. The base
houses the mechanism, which consists of two coils of wire wrapped around
an iron core.

At the top of the mechanism is a set of silver contact "points" (like
the end of a wire); one usually on a spring mechanism, the other either
the end, or on the end of a screw.

The spring connects to the base and a bar, which is connected to the
needle arm (90 degrees offset). The needle arm is connected to the
needles (which are soldered onto the bar), and moves up and down inside
the sanitary tube.

The coils connect to a DC power supply (between 6 - 12VDC), via a spring
coiled U-cable. The U-cable is called a "clip cord," designed to move
easily between machines but also stay in place and not fall out and
spark all over the place. The springs hold the cable in/onto the
machine.

One side of the coils is connected to the power supply, the other end to
the point on the screw on the bunny ear, which is insulated from the
base. Through the points, the current flows via the coils and the base
of the machine. This causes the coils to become electromagnetic. The
electro-magnet pulls down the bar, which does two things: pulls down the
needles, and opens the points. The points being open turn off the
magnet. The spring assembly brings back the bar, which causes the
needles to move up *AND* make contact with the points. This causes the
whole cycle to happen again making the needles go up and down.

Most machines have a large capacitor across the coils/points, which
keeps the points from arcing and pitting, and wearing out so quickly. A
capacitor is a device that holds energy kind of like a battery, but
charges and discharges much faster (parts of a second rather than 3 or 4
hours). The capacitor charges while the points are open, so when they
close, the difference in voltage across them is nill. The points are
really an automatic switch controlled by the spring to turn the thing
off and on quickly. In old cars where there were points there was a
condenser (aka capacitor) for the same reason.

The sanitary tube sucks up the ink in capillary fashion, and the needles
load up as long as there's ink in the small portion of the tube.It's
called "sanitary" because of the cutout at the bottom of the tube, which
can be rinsed out.

My understanding is that there are three layers of skin: Scaly layer,
epidermis, and dermis. Tattoo machines are adjusted to penetrate into
the dermis layer but NOT *through* it (below it is the fat layer of the
body).

When the needles go into the sanitary tube they have a layer of ink on
and between them. The needles make little holes in the skin, and the ink
is deposited into the holes. This is why the skin has to be stretched so
blobs of ink don't stay. Otherwise, the skin will latch onto the
needles, grab the ink from them and generally make a mess.

Ink just put into the scaly layer would be replaced quickly and fade
away. While ink into the epidermis will stay, my conjecture is that the
dermis makes for more ink and perhaps a more vivid image.

Machines are really of two types: Liners, and shaders. They are-exactly
the same, but are set up differently. The gap for a liner is-around

the thickness of a dime, and a shader is the thickness of a nickel.

Liner needles are usually arranged on the bar in a circular pattern.
Shader needles are usually straight (like a comb), although Spaulding &
Rogers sells a 15-needle round shader. The needles are small sewing
machine needles, usually made of stainless steel. Liners are in 1, 3, 4,
5, & 7-needle combinations, set in a round configuration. Note: There
can really be any number of them but these seem to be most common.

Shader needles are in a straight row and usually are in groups of 4, 6,
7, 9 needles. The sanitary tubes are designed especially for the
combination of needles, so there's a special tube for each different
number of needles in a needle bar assembly.

the artist manipulates the skin while tattooing. This is learned by 
experience and by hands-on apprenticeship or tutoring, and is one of the
 reasons that learning from another artist is the approved and safest 
way to get involved in tattooing.

While the machine's force and physics do make a difference to 

the end product, there is no way to make a machine that will

mechanically adjust
precisely enough to account for variations in skin surface, texture, 
and tone on a microscopic level, which is what an experienced tattoo 
artist does while working, manually, by adjusting their stretch 

and hand positions.

"Vick"