Welcome to another informative and breathtaking installation of our unending stream of tattoo industry related awesomeness and mind-bending fact-ness. (That is NOW a thing. Coin it.) Today, kats, dolls, and all points in between, we’re going to dip our toesies in the turgid waters of the Rotary versus Coil debate. Strap in, buckaroos, we’re in Indian country now.
Some of you may have noticed over the last 5 or 6 years that it is becoming common to walk in to a tattoo venue and hear…nothing. No blasting music. No shouted conversations. No spitting, rattling, sparking electric buzz of a tattoo machine howling into the void to give a reason for the other things I just mentioned! I know, I know…it’s a little weird. I’ve been in the game for 15 years, and I can tell you, things are changing. Rapidly. Mostly, for the better.
To be fair, let me start this way. Tattooing, until recently, was performed primarily by use of a sprung-armature, electromagnetic coil machine. The reason the design of this machine remained the same since before the turn of the 20th century is, quite simply, it worked. Perfectly. Countless variations on the design, with adherence to original concepts, produced tattoo machines that were (and still are) purebred art instruments that are a pleasure to use and a breeze to maintain. The downfall? The copper wrapped iron-core coils, spring arrangement and armature requires a rather large (and therefore HEAVY) frame to carry it all. With multiple points of wear, for example: front spring, rear spring, coil tail wires, capacitor, contact point, or even the copper of the wire wrappings of the coils could and would wear out and fail. Sometimes, pretty spectacularly.
Additionally, all of these fatigue points lead to constant adjustment and tuning of the machines. This was a “Sword of Damocles” type situation. You see, good people of the Googlenets, at least the coil-type machines provided just enough Pain In The Ass factor to ensure most tattoo artists knew a good bit about how their equipment worked and why. Unfortunately, this is something that seems to be fading a bit with the newer technology on the rise…but all things must change.
Taking the stage and stealing the limelight, as it were, are the Rotary tattoo machines. These little bad boys are the reason for the echoing silence descending on tattoo venues near you. Technically speaking, this scientific minded artist thinks they should be called “Sterling Machines,” as their motion, even when touted as ‘direct-drive’ is eccentric to a rotating base-circle, and therefore defined as a Sterling motion. That’s my soap-box lecture, for you. Enjoy that one? Anyway…
The upsides to rotary machines are many. They are very small, very quiet, produce much less vibration, and generally tend to be more energy efficient. This can help reduce the difficulties caused by carpal-tunnel syndrome and tinnitus, both VERY common maladies that affect our industry on a daily basis. My ears STILL ring from listening to that buzz, day in and day out for over twelve years. Another benefit of the over-engineered rotary tattoo machine is pure accuracy in any situation. Let me explain. WARNING! SCIENCE AHEAD!
With each stroke of a traditional coil machine, several variables are at work. We’ll focus on the two most important of them…spring tension and magnetic torus (the ovoid field effect the electromagnets produce to draw the armature bar down against spring pressure.) A metal spring, with every flex through its rate (range of motion) causes fatigue, resulting in reduction of the rate of the spring over time…this is known in the car world as spring-sag. It applies to ALL springs. As the front and rear springs receive differing forces of flexion, thus wearing at WILDY different rates, there exist a rather large margin of error in terms of the sprung resistance force on the armature’s down-swing; the part of the coil machine’s movement that applies to this discourse.
Add to all of this a tantalum electrolyte capacitor, complete with its own rather large error margin, controlling the cycle of electrical events producing the Torus… the magnetic field that pulls the armature bar to the coil top, breaking the cycle, allowing the spring set to up-swing and slap the energized contact point, and again, and again, ad nauseam. WHEW!
This is not to say rotaries don’t have their own PITA factors. They’re terribly expensive, for one. I could buy two or three powerful, solid coil machines for what I spent on just ONE next-gen rotary. Adjustments come in the form of eccentric cams. The eccentric point rides at a different location on the large base-circle, thus producing longer or shorter ‘throw’ cams. The exceptionally smart will have already figured out that this now requires at least two bearings to accomplish. Know what bearings like to do? They love to wear out and break for, like, no reason at all.
The precision of a bearing regulated Sterling motion cannot be doubted, however. Look at sewing machines…same concept. Locomotives…yep. Every swing of the circle, the eccentric bearing swings through EXACTLY the same arc of travel, producing identical results with each rotation, provided no variance in input voltage. Rotary motors, unlike springs, are largely unaffected by resistance forces, and have ample torque to penetrate at even extremely low RPM. This is another “Sword of Damocles.” (Hah…gonna be a top search on Google with people trying to figure out who the hell Damocles is and why his sword is so interesting.) With all that penetration torque on tap, and the ability to run smoothly at absurdly high RPM, these little beauties have the ability to become a scalpel in the wrong hands. Linger too long in one spot, and you dig a hole to Peking.
I suppose the point, if one has to be made, is that there are ups and downs to both styles of tattoo machines. Those of us who made the switch to rotary machines embrace the upswing in technological improvement making waves through our art form. New tools equal new techniques and new possibilities. Those who eschew the new tools are also not incorrect in their choice. Known tools and techniques produce known and reliable results. There are always multiple sides to the story, with varying levels of intensity.
I’ll leave you with this, intrepid readers of interweb wisdoms:
The Litmus Test in all of this debate is results, y’all. If some guy or gal throws turds with a coil, they’re going to throw turds with a rotary, and vice-versa. If I know how to destroy a game of pool, it doesn’t matter if I’m using a house cue or a $1000 McDermott. I’ll smoke you with the handle of that broom over there…