Rotary Tattoo Machines

The following is a conversation I had with an artist via e-mail where we discussed many of the questions that I'm frequently asked. i asked for permission to post it here to be resource for others looking for the same answers. Please enjoy!

Hello joshua
Im a tattoo artist in France, I’ve been tattooing for 5 years and
I've always worked with coils. I've only tried a rotary neotat and a Hawk Thunder machines for a time but I dont like it, the machines dont have force to penetrate solid ,i miss the slap of coils.
I read aaron cain said that rotaries aren’t good for solid work.
I am a little confused. I see some tattooists that I like use your machines and your work looks solid, as you make both coils and rotarys can you tell your opinion please?
I like to buy one of your rotarys but im afraid that they don’t have force
Sorry my english


JB- In my opinion rotaries don't have the slap per say of a coil but they are more powerful. It's all about the stroke. Coil stroke starts off strong and then weakens as the needles move down. Which gives it that "snap" that your referring to. Rotaries carry the same force and roughly the same speed all the way through the stroke. Which makes it more powerful. Saturation is obtained by the ability to hang the needles in the skin just a touch longer so your hand movement opens up the skin a little bit more to deposit more ink with less holes. You have more ability to do this with rotaries because you have full control of needle speed, where with a coil your only controlling speed as a function of force, but mostly just adjusting force. 

So a rotary will feel less forceful than a coil when ran properly but is much more efficient. It should be avoided to turn the rotary up so far as to get the same hand feel as the coils your used to running. If you run a rotary too fast and too hard it won't open the skin at all and will just cause a lot of trauma.


S- Thank you so much for your help joshua
So maybe I guess that my mistake is that I always try to feel a rotary as a coil.
As you said we shouldn’t run a rotary so fast as a coil ,so we need a rotary with a motor with a very good torque,yes?
Because to get force in a rotary we need put more voltage,and more voltage/more speed
What the stroke you have in your machines is 4mm?
The neotat I try have 4.2mm


JB-  Every motor is different. One mistake that people make is thinking that a 4mm cam is going to react the same way on another machine as it did on the last. Every machine is built and designed differently, different motor, different offset and different frame geometry, etc. You don't need a lot of torque you just need the right amount of torque at the right speed. If the machine is too torquey at lower speeds then it will have too much torque at operating speeds and tear up the skin. If it doesn't have enough torque you will have to turn it up too much to get the torque you need to penetrate the skin, that increases the speed causing the machine to run too fast and will tear up the skin. 

There's no magic formula that works for every machine. I tune my machines to be ideal machines for tattooing because I understand tattooing, I'm less concerned with simply making a mechanism that makes a needle go up and down. Most rotaries on the market are just that, mechanisms that make a needle go up and down. By using the frame geometry, the cam offset as a lever and a couple other tricks I’ve developed I can create a stroke in the machine that slows down and responds to the skin at just the right spot in the machine stroke. This is how I tune my rotaries. 


S-  And about a direct drive rotary(circular movement) and a rotary with an up down movement ? Of course that depends of the machine. But some people defend that a direct rotary machine is better for solid tattoo, because the other rotaries with an up/down movement the needle spends more time in the down movement.
You agree?


JB-  I don't like direct drives unless your stippling with them or running cartridges.


S-  Sorry but,why is best for cartridges? Is a direct drive more powerful?


JB-  Because a direct drive can't really be tuned. There's no mechanism for modifying the stroke characteristic besides adding weight to the spindle mass, but this rarely offers any benefit to making a tattoo machine better at tattooing, it usually just adds a bit of force to the initial contact with the skin and then slows the movement down from there. Direct drives also cause a wobble in your needles since they have no mechanism for making rotational movement into linear movement. So the needles move side to side often times causing friction and rubbing on the sides of the tube. The use of cartridges with this system solves those potential problems.

These are questions a lot of people have, I would like to post this conversation to my website blog if that's ok, it would help answer a lot of questions for people.