Tattoo Machine Electromagnetic Coils 101.

Tattoo machine coils; with internal wire layers and core shown. Insulation around the core is not shown here.

The front and back coils are the motor of the machine. When power comes into the circuit the coils pull the armature bar down, (with magnetism) disconnecting the contact screw from the front contact spring, this opens the circuit and causes the coils to lose magnetic force returning the armature bar back to its original position; the contact screw and front contact spring reconnect closing the circuit. Thus returning power to the coils creating a rapid loop of the circuit opening and closing.

Why are there 2 coils?

What a single tattoo machine coil is on the most basic level.

62 Horseshoe Electromagnet The natural method then is to bend tlie core in the form of U and place a coil on each limb as in Fig 105 This form is however rather inconvenient to make and the bend takes up too much room as a rule therefore the practical horseshoe elec c Fig 105 Horsesbqe Electromagnet Fig lOti Practical Horseshoe Electromagnet tromagnet is made of three pieces besides the armature In this form Fig 106 the wire is wound directly on to the insulated cores and the latter are then fastened to the yoke or back iron as it is often called Click the image above to read the entire book for free.

Fig 50 In this form Fig 5 1 the wire is wound directly on to the cores and they are then fastened to the yoke or back iron as it is often called Fig 51 While this form is very efficient there is a loss due to the joints between the cores and yoke

Click the above image to read the book this was taken from as well.

If the frame is made of a material that facilitates this i.e., (iron.) Then you will not need a machine part called a, “yoke” to connect the two magnets. This is done to increase the magnetic force by directing both magnetic poles towards the armature bar.

There are a lot of tweaks and custom set ups for coils but the 3 basic sizes you will see are: 8 layer, 10 layer, and 12 layer. And bigger does not mean better.

The number represents how many times the coil core has been completely wound up and down the surface of the core. What is the difference in layers? The more layers the stronger the magnet. But that is not the only thing that will affect the coils behavior. Wire gauge, wind direction, wire composition, how tight the wire is wound, the material the core is made from, surface area of the armature bar, surface area of the top of the cores, if the core is properly insulated, and the capacitor paired with the coil/coils will all affect the behavior.

The more layers a coil has the more voltage will be needed to power the coil and the harder it will, “hit” bring the armature bar down. Bigger coils mean more force and more voltage to run. More force equals more trauma to the skin and more voltage equates to more heat; use the right components to get the job done.

You always want to make sure your coils are wound in phase. In phase simply means the coils are both wound in the same direction. This way the north and south poles of the magnetic fields will sync up.

67 Polarity of Electromagnets In practice the exciting coils of horseshoe electromagnets are all wound in the same direction After the spools are mounted on the yoke or back iron the inside terminals of the coils are connected together leaving the outer terminals for making connection to other apparatus Sometimes the coils are connected in

The basic materials to build a coil are:

A core made from 1018 steel or low carbon iron. Commonly 1 1/4″ high. With 5/16″ or 2/8″ diameter. Threaded with #8/32 inside the core to connect it to the frame. Note: There are higher quality cores than the basic 1018 steel ones available on the net.

Insulation for the core, (Kapton tape, teflon tape.) 2 layers wrapped around the core is good.

E clips and non conductive insulating washers i.e., (phenolic or fiber.) Commonly 3/4″ outer diameter. Clips not shown.

24 AWG insulated magnetic copper wire. The funky coloring of the wire is do to it being coated in a polymer to insulate it.

A cover for the finished outside of the coil i.e., (shrink wrap tubing, coated in sealant, or other type of custom cover.)

If you’re looking for high quality coils out of the box, then these Mary Jane coils by Dead Nuts Ink are excellent hand crafted coils.

9 thoughts on “Tattoo Machine Electromagnetic Coils 101.

  1. I hope you can help me with some trouble I’m having,
    I recently started building my own tattoo machines.
    Everything from the frame to the ciols. On a shader- color machine,
    I used 5/16 cores with 8 wrap 22 gauge wire, and a 47uf capasitor.
    The power of these coils is good, the problem is they get hot, the capasitor gets really hot, even my power supply burnt out. Don’t know if the core is not properly insulated, I don’t use a bobbin, just isulating with shrink wrap, or masking tape. Is the 22 gauge wire is too much?
    So I changed the core to 3/8 using 24 gauge wire, this did not over heat as much, Just stayed warm, The problem here is that it is too noisy and clattery.
    I’m thinking it doesn’t have enough power due to the thicker core and only 8 wrap 24 gauge wire! I will try using the 5/16 core, now with 10 wrap 24 gauge wire.
    If there’s any advise you can give me, I will greatly apreciate it,
    At this piont I don’t know if it’s the wire gauge and core thickness, the insulating of the core, or what? I’ve looked over all aspects of the machine build, Capasitor negative lead down-positive up, more tension, less tension on the springs.

    Hope you can help!

    • You need to go threw and list everything out in the circuit that can fail:

      1. Power supply

      If you have a power supply that isn’t good quality or has a defect you can not trust it. You need to grab a decent multimeter and test your power supply. If you can’t afford a good power supply, I’m posting these articles so you can learn more about them, and build your own custom lab power supplies for free. To test it just hook up your multimeter to your supply, run it continuously, turn it up and down, and stress test it. You may be surprised to find that the multimeter reveals that your supply is running very poorly and that was the cause of your head ache the whole time. I have come across bad power supplies that seem like they are running correctly but cause any machine connected to them to fail horribly.

      2. Are the coils in phase?

      Check to see if both coils were wound in the same direction, “in phase.” If they are not in phase the magnetic poles won’t be synced up and will cause your problem.

      3. Capacitor

      The capacitors you have may be faulty. Test them. Even if they look good they may be defective and you won’t be able to tell unless you run a proper test.

      4. Wire

      Is the wire good quality insulated copper wire? Maybe the insulating polymer on the wire is defective/old and it’s making a contact in the coil wraps? Or the wire isn’t a good quality copper alloy.

      5. Is the circuit insulated from the frame adequately?

      Check to see if your grounding out on your frame somewhere. Maybe one of the lugs is touching the frame.

      6. Frame needs a yoke.

      Maybe your frame is made from a material that isn’t magnetic and needs a yoke.

      7. Yoke

      If your yoke is too thin or is made from a material that doesn’t facilitate magnetic fields that would be a problem. Replace it with a decent sized iron one, (at least 2mm thick.)

      8. Armature bar

      Test your armature bar. It might be made from poor alloys. How to spark test it.

      9. Cores

      Test to see if your cores are made from poor alloys just like you tested the armature bar. 1018 steel is fine but iron will work even better. You sound like you’re insulating your cores so I don’t think that would be the problem. You may want to use a better insulator. Like Kapton tape or something designed for that kind of electronic application.

      10. carbon build up.

      Check all the connections for carbon build up. Where your clip cord plus into the machine, the contact spring/screw, and front coil core. You might as well clean them as you inspect so you can write it off as a problem.

      Note: it sounds like you know what’s going on; which leads me to believe your power supply is probably causing the issue. Are you running the machine loaded with a needle and rubber bands? Or is this issue happening without any load on the system?

      Oh I forgot to add that you might have a bad frame as well. Check those stroke gaps and how it lines everything up; spring deck; all that stuff. I don’t know what kind of frame you have so I just covered everything for you.

      And the wire gauge isn’t going to screw up the machine like that. You’re just spooking yourself about that. It’s more likely that you fixed a problem when you changed the coils and didn’t even notice what you did. I think it might be that your springs aren’t made from good spring steel and/or are causing the armature bar action to be too stiff; just another after thought. You want to ad springs to that list as well. Check that gap between the rear of the armature bar and the spring deck too close on a shader will do that; you can grind the rear of the armature bar down to give it a better diving board effect.

    • Thanks for the comment. I’ll have to write an article on the different core shapes/sizes and special core top designs. I think core diameter will effect surface area for you to make your layer windings and will put a limit on the magnetic force the coil can generate at max power. So a fatter coil core will let you saturate the coil with more magnetic force. So after you hit the limit more voltage won’t increase the core’s magnetic force. It will also alter the spread of the magnetic field coming out of the coil. A larger diameter will spread out the magnetic field wider; which is why T-tops are used. T-tops are intended to spread out the surface area to grab more of the armature bar but give you a smaller core. So yes, you would want to try and use the right core size for the job as well. I’m not sure what the voltage would be to saturate a standard core size. However, I think using a iron core rather than a steel one would be the real benefit; rather than messing too much with core diameter. Iron will hold more magnetic force and become magnetized and demagnetized quicker than steel. It’s not just a small difference from iron to steel either. I’ll have to create an article solely on cores. Thanks for the question.

  2. I am looking to start winding my own coils. I am just looking for how to start. I have looked into the wire, coil cores, washers, etc. that I will need. I have researched it quite a bit but I cannot find anything in detail about how to start a wrap. Any help will be appeciated. Thanks.

    • I have gotten a ton of requests for this. My next article will have video and pictures showing how to build a cheap winder and how to wrap a coil. I will have links to parts and everything. I hope I can get you and everyone else wrapping your own quality coils as I am seeing that this is one thing most people want/need to take their skill set higher.

  3. I was wondering if there is a certain direction to wind the coils. I get the part about winding them in the same direction to keep them in phase. What’s the difference between winding them clock wise or counter clock wise or does this even make a difference.

    • As long as they are in phase you will see no difference. All changing wind direction will do is flip the poles around. And you can’t even really tell witch pole is S and witch one is N. The trouble comes from having out of phase poles where the fields will screw with each other.

  4. Hi there!
    Great article, I could really find some interesting stuff here.
    About the chart above with the wraps and the type of machine, I would add some information.
    Regarding the wraps, I’ve never build anything over 9 wrap coil for a shader. Why? the machines from the past could yet drag big mags, the problem was the spring stock, it was not tempered and thick, forcing the machine to run on 12 volts.
    Now days, even a 6 wrap coil with a 5/16” x 1 inch coil core drags a 9M on 6-7 volts. The thinner and harder spring stock we have makes the bar move easier and smoother.
    I think the secret to use big groups is not the coil size, it’s all about how you move your hand. Try to pack color in a slow movement, allowing the needle to break up the skin and leave some ink ( those are two actions that happens when tattooing, needle first breaks, then inks the hole).
    If you move your hand slow, you will see how effective you become, you won’t need to go fast because fast ain’t solid..and we all know it after ten years of seeing our work healed.
    By being smother, you will also allow the machine to work in low voltage, remember that the perfect sound is when the machines “drowns” in to the skin.
    There’s another thing you have to check out if your machine warms up to much..machine bags . Always check if the machine heats up without the bag, and always use a foot switch. Capacitors are important too. Just get the best, a dollar capacitor already makes a big difference.
    Bigger coils are heavier too, remember.

    Once again,congratulations for your page

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