360 view
tattoo machines
sanitary supplies
replacement parts
tattools in use


Light (soft) spring tension = 1/2 w x .020 gauge springs with a #4 armature bar.
Light Medium tension = 1/2 w x .020 gauge springs with a #3 armature bar.
Medium tension = 1/2 w x .020 gauge springs with a #2 armature bar.
Medium heavy tension = 1/2 w x .020 gauge springs with a #1 armature bar.
Heavy spring tension = Any spring with a thickness greater than 20 gauge,
or wider than 1/2 inch. Or any 1/2 wide spring that has been bent.

Extra long stroke - Above 0.150 of an inch
Long stroke = .1350 to 0.150 of an inch
Medium long stroke = 0.135 of an inch
Medium Short stroke = 0.125 to .135 of an inch
Short stroke = less than 0.125 of an inch.

If you want a long stroke detail or soft shader machine, use light or light medium spring tension and a long stroke. Soft spring tension and long stroke allows the needles to change directions smoother, for smoother tattoo effects.
If you want a stronger hitting machine, turn up the power (a little at a time) until the needles are pushed to the skin to the right depth. With a long stroke and soft springs and the right power setting and hand speed the machine will push large (or small) amounts of needles into the skin to the right depth with ease and without problems. I recommend using the longest stroke, and largest group of needles feasible for the skin you’re tattooing and the effects you are applying.
If you want a shader machine for solid color, use medium spring tension, medium stroke length and just enough hand speed and electrical power to do the job.
If you want a shader machine for a large round liner/shader, use light medium spring tension and medium-long stroke. This setup is also good for sculpting lines. Shorten the stroke
length by 0.025 of an inch or so, and you’ll have a very good hard liner machine.
If you’re setting up a hard-liner machine, try medium tension and medium stroke length. And just enough power to do the job.
Use an extra long stroke for that fresh “San Quentin” powder shading effect. This is how you match prison style shading techniques. With a 3 round group of needles and an extra long stroke, you can get very nice highly detailed stipple effects that look just like those done in the joint.
If you want a harder hitting fast acting machine, there are two ways to get the machine to run that way. Increasing the spring tension, and/or shorten the stroke, or a little of both. I recommend increasing the springs tension - a little bit - before changing the stroke length. You can increase spring tension a little at a time, by reducing the free spring area of the rear spring by using a cut back armature bar. see fig. M7, M8. See spring section for more details

If you prefer a Heavy, or stronger spring tension (faster action) than is possible to get with a cutback armature bar, or you would like your K model machine to run more like a fixed spring machine. I recommend you just readjust the machine to give you the extra spring tension you need. Tightening the point screw compresses the main spring. Compressing the main spring increases needle force. Tightening the point screw until you have the desired needle force, and then readjusting the stroke length a little at a time until you have the stroke length and needle force combination you want is very easy to do.
Here’s how to do that:
#1-Tune the machine to the stroke length you would like to have and fine tune, in other words, tighten the point screw until you find the sweet-spot as previously described.
#2-Now, continue tightening the point screw one full turn (or so) past the first harmonic balance point, this will compress the main spring a little more. At this time the machine should be running harder, and with a shorter stroke than you should tattoo with.
#3-Now, without changing the point screw, loosen the top binding screw a half turn, then tighten the bottom binding screw a little bit, just enough to give you the stroke length you want, (probably less than 1/4 turn ) this will lengthen the stroke a few thousandths of an inch, then tighten the top binding screw.
#4-Now tighten the point screw very slow, within a quarter of a turn, you should find a sweet-spot, where the machine runs fairly smooth, and a little stronger.
#5-Reset the tip of the tube so the needle tips are just inside the tube tip. Hold the arm-bar against the coil post and look at the needle point protruding from the tube tip. If this is the stroke length you want, step on the gas to see if you have the needle force you want. If it is, good, if not make very small adjustment to the point screw until you find the sweet-spot that gives you the needle force you want, then reset the stroke length by tightening the bottom binding screw until the needle point retract back into the tube tip. This will set the stroke length to the length you set earlier. Step on the gas to see if this produces the right stoke and needle force you’re looking for. If it isn’t repeat the procedure until it is. Once you understand this procedure you will be able to change and reset the stroke and needle force as desired within a few seconds, it really is quit simple.

There are too many different combinations of stroke lengths and/or and spring tension that It is impossible to tell you exactly where the harmonic balance point is for the setting you choose, but with a little practice you’ll be able to find the sweet-spot, regardless of the actual stroke length, as long as the spring tension is within a working range of the skin tension. Remember; when spring tension is greater than necessary, you begin fighting the machine for reasonable hand speed.
There are many combinations of different spring tension, stroke length, and power settings not listed here. You will have to discover these settings on your own. (That’s what experience is). A good rule of thumb is, longer stroke equals softer shading, soft shading equals elegant details. Transparent shading and the layering of pure color should be considered detail. Hard and fast hand movement is not often the best method for layering detail of any kind.

When replacing either spring, I recommend replacing it with a straight spring of equal dimensions. It is easier to repeat or predict how the machine will run when a broken spring is replaced with a spring of equal dimensions. It’s also much easier to compare one spring set-up to another spring set-up when straight springs are used. Being able to make one machine run like another, takes the struggle out of operating a set of machines. Being able to totally control, and make your machines run similar to one another, but different, makes tattooing more predictable and fun to do. (If you’re n Old Dog, learning to control your machine to this degree will create room for your imagination to grow. Guaranteed to bring the fun back to tattooing)

Capacitors certainly help all tattoo machines run smoother. And they help maintain a certain “speed” when used on fixed spring machines. But when you have an adjustable stroke machine, the speed of the capacitor isn’t the most important aspect of how capacitors contribute to the smooth operation of the machine. The ability to adjust the stroke length pretty much over rides the speed of the capacitor. We have found that capacitors with a 47 and 100 UF 35 volt rating last longer and work better than capacitors with lower UF ratings. Capacitors actually help provide a more constant flow of the horse power and torque needed to move the arm-bar assembly the longer stroke distance.

One rubber band is necessary to hold the needle bar in place. Adding a second, third or more rubber bands greatly increases the friction where the needles contact the tube tip, causing undue needle wear. This built up friction, also increases resistance, this resistance requires more power from the power source just to make the machine run. When it takes more power to run the machine than it actually takes to push the needles into the skin, you have a machine that runs too hard to control with finesse.
Adding one #12 rubber band at a time increases the power requirements of the machine in a small some what predictable amount. In the “Olden Days ” when machines were hard to come by, a good way to regulate a small change in the way the machine actually runs was to add a rubberband or two. Adding or subtracting a couple of rubber bands would change a liner machine into a shader machine and visa versa.
Changing the way the machine runs, in such a crude method as adding or subtracting rubber bands certainly works to some degree, and works best if the rubber bands are fresh. But now a days, with easy access to affordable tattoo machines, you can easily have several differently tuned machines. Using more than one rubber band to hold the needles in place isn’t necessary. One rubber band will do the job, just keep it fresh.

Tattoo machines are actually very precise instruments, they will repeat performance millions of times, and respond to the slightest of changes. For a well tuned machine, a very slight change in any of the components, like adding another rubber band, or changing the power setting by even one tenth of a volt can change the way the needles penetrate and exit the skin. The skin is such a delicate medium that it really doesn’t take much change in the way needles hit the skin to make a good or bad difference. A small change may even influence the way the machine actually operates, to the degree that a small change can restrict the technical effects possible. That is why you may have more than one type of shader machines, or more than one type of liner machines. A variety of different lining and shading effects are easier done with the stroke length that compliments the needle group size and shape.
 If your machine doesn’t respond to small, (1/3 volt or less) changes in voltage, or won’t run with less power than it takes to push a needle into the skin, your machine is not properly tuned, and hits the skin harder than necessary.

Large armature bars work best on all machines. They slow things down a little, and tremendously help with the kinetic energy. Smaller armature bars make soft shading more difficult to do because they don’t carry kinetic energy very well. But they do help make a light liner machine a little more snappy.
Springs without contact points work as well as those that have them. But the contact screw burns a hole through the carbon steel spring quicker without a contact point. Not that it matters, but they also sound different, but this sound change doesn’t make the machine run any differently.
Rubber O-rings around front springs have no practical value. They actually increase front spring tension, which limits the functionality of the machine. Over powered springs and machines, are the top two restriction to the advancement of practical modern tattooing techniques. Over powered springs and machines increase your hand speed. High hand speed diminishes detail and retards your imagination. Anything that increases speed or spring tension diminishes detail of all kinds.
Increasing spring tension much beyond the tension needed to pull the needles from the skin eventually becomes counter productive to the fine art of tattooing. But I will say that there is a certain “range” of spring tension that work well within the range of skin conditions. Just knowing that small things make large differences in the way springs and machines work, gives you control of the motion of things.

Experiment a little, with stroke and point settings, you certainly can’t hurt a K model machine by retuning it. And it only takes a few seconds. The more you know, the more you grow.

The sound to judge your machine by, is the sound made when the needles are in the skin. It should be a nice smooth hum with an occasional clatter of the armature bar hitting the coils post when the needles are pulled form the skin between strokes. Even when you’re shading with a very light touch the bounce of the springs won’t effect the results of the needles performance.
You’ll not see a problem with this spring bounce because, with soft springs, even the slightest touch of the needles to the skin has a controllable effect on the machine, and the spring bounce will stop. If the spring bounce doesn’t stop, you have more than enough power going to the machine for the desired effect.

You won’t hear this stuttering on most commercially available machines because of the O-rings, short stroke and lower voltage makes the machine sound - fast and smooth - right out of the box. This fast smooth sound is a sales tactic that has evolved as a standard for the professions inexperienced tattooers. You can tell a lot about a tattooists style and experience by the sound of their machine. The buzz of a hard hitting fast acting machine is a sign of the lack of experience, or an indication of a very limited style of tattooing, or both.

The chatter of the contact points, the swish of the needles, and the - occasional - clatter of the arm-bar touching the coil post should be what you hear when tattooing with a properly tuned machine.

Continue to, Machine Springs and Coils - What they actually do
artattoo magazine
the institute of tattoo arts