Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Research on tattoo machine mechanics

  1. May 24, 2007 #1
    Hi, I'm new to the site. I posted this question in another thread to no avail, so I'll try starting over with a new one of my own. I am doing research on tattoo machine mechanics and this came up in Google. It is very interesting, so here I am. I don't have a lot of technical knowledge regarding any of the systems at work here, but I do have a general idea based on what I have been reading. Tattoo machines have a lot going on when in operation. They have an electrical system, a magnetic system created by the electrical system, and a mechanical system that is operated by the magnetic system. I am fairly intuitive and can learn almost anything. I am fascinated with these machines and want to be able to build my own. I have done a few rebuilds and have run into some issues that I need some technical assistance with. I have a few different questions, but I'll try to work them out one at a time so I don't get any more confused.
    The basic function of the machine is to place tattoo ink into the dermis of a person's skin. Different people have different skin and the required needle configurations differ as well which require different amounts of force to accomplish this. The machine must generate enough force to drive the needle configuration into where it needs to be. Also different skin types require different amounts of force and different depths of needle travel. The taper of the needle tips are also a factor. For example a single, long taper needle does not require much force to go into thin skin. On the other hand it takes much more force to drive 13 short taper needles into tough skin.
    The electromagnets of the machine use electricity to create "pull" on the steel armature of the machine. The needle configuration is attached to this armature so as to move with it. The distance of travel, or stroke, is determined by; the bottom gap (space between the armature and the magnet surface) and the amount of front spring compression. A rear spring attached to the base frame of the machine applies force to the front spring and is used to counteract the magnetic pull. At rest, the front spring is compressed against the electrical contact completing an electrical circuit used to power the magnets. When you step on the foot switch and apply voltage to the circuit, the magnets pull the armature toward them releasing the front spring compression until the circuit is broken as the front spring leaves the contact point. This begins the "open" part of the oscillation. The armature continues to the magnet surface form inertia until it hits. The rear spring then takes over and returns the armature to the contact point, ending open contact time and beginning the "closed" part of the oscillation. The front spring compresses against the contact point from inertia and then the magnets pull it down again for the next oscillation. This happens many times per second, most machines run between 100 and 150 hertz. The balance between open and closed contact time results in the machine's duty cycle, which is critical for a well running machine. This duty cycle is a relationship between bottom gap, contact point gap, and front spring compression, which also equal the stroke of the needle. The weight of the armature, the stiffness of the rear spring, the needle configuration, and skin type are all factors in how much pull is required.
    My first question is how to maximize the efficiency of the voltage used to power the magnets. Standard magnets are made by taking 1" or 1-1/4" lengths of 5/16" or 3/8" diameter 1018 low carbon steel rod, insulating it with a thin layer, putting ends on it to form a spool and winding 24 or 26 gauge magnet wire around it, 8 - 12 layers thick. I am currently planning on making my own coils and am hoping to get some insight into how to maximize the efficiency of the voltage in the coil. What effect the diameter and length of the steel and the gauge and length of wire have on how the electricity is used to create the magnetic pull???
    I realize that this may be menial to some of you, but any comments on this are greatly appreciated. I have been digging for this type of info all over the web, but am having a hard time finding exactly what I need.:smile:
  2. jcsd
  3. Jun 6, 2007 #2
    Hi youfourian,

    you can find answer to your question by opening a dot matrix print head. it operates the similar way you explained in your question.

    If you have answer for my question pls ans.

    that is why in this kind of application coils get short, when all parameter are under control?
  4. Jun 12, 2007 #3
    hey, I build one off tattoo machines. As far as coils go, For the cores use the the lowest carbon content steel available. 1018 is standard but if you can find it 1008 or 1002 is best inch and a quarter long. Use 24 awg wire, insulate the cores with varnish & tape and wind your wire as evenly and tightly as you can, six to eight layers, just count, you can use a meter and check to make sure eight layer coils should have 1 ohm each and combined a resistance of 2. anyhow if it ain't broke don't fix it. I figured that out the hard way. Everything else is determined by your geometry and springs, and the way you tune your machines stroke, speed etc. balancing your mechanical and magnetic systems is more important that making a "better" magnet. Voltage is going to be determined by more factors than your coils.
  5. Jun 25, 2007 #4
    Thanks Pilot, that's what I was hoping to hear. The cores I got are 1012 steel. Varnish and tape for insulation? Someone else I talk to uses heat shrink tubing and I was going to use that. What type of varnish? Also I've seen a lot of "stilted" front coils lately and was curious about that.
    Any more info on the balancing of the systems would be greatly appreciated as well. Thank you for the reply:wink:
  6. Jun 26, 2007 #5
    Red electrical insulation varnish, and then a layer of masking tape. Heat shrink would work as well, the point being that you do not want any contact of your magnet wire with the core. I dont know exactly what stilted coils are. I have seen coils on e-bay that were called "stilted" it looks to me like a satndard 1"1/4 core with the bobbin moved down, so you've got an 1" core. The top of the core is the "stilt" I have no idea why someone would do this. Balancing your Mechanical and magnetic systems is dependent on what you are trying to make that machine do ie. speed, stroke length, liner, shader, color machine. This has everything to do with the way you tattoo. I don't think you can hand someone a machine and say this machine runs perfect. You want an effecient machine for it's purpose, less wasted energy. This is the "balance" I'am talking about. In my opinion a quick indicator, is the voltage a machine requires, when you get up above 8 volts You need to start looking for problems. Sorry but I have to ask, you work in a shop? I hope.
  7. Jul 1, 2007 #6
    I'm going with the heatshrink.

    I don't actually tattoo for a living yet. I've done a few on myself and one on my wife. I'm not tattooing other people and will not until I do find a place to work. I'm just learning as much as I can in the meantime. I'm going to do more on myself to test my stuff though. As you will understand, I didn't get a warm welcome in the tattoo forums, so I decided to seek info in other places. Fear not, I'm not a scratcher except to myself and I understand the importance of safety and sterilization and sanitation practices. I don't want that rep. I'm not ashamed of any of mine, I don't hide them. I see a lot of other people who are not so fortunate though and even if I did tattoo people, at least they would be nice looking to the average person. I need to do some re-shading on a couple of them, but the designs and placement are good. A pro would pick me apart though and I don't want to tattoo others until I would be proud to show a pro. I'm just working on getting my machines in order. They work OK, but they could be tuned better. I make my own springs and am working on coils now and am seeking the same info as you concerning heat. That is why I was looking for info on magnet efficiency as far as parts are concerned.

    No apologies necessary for your concern and any info is appreciated. Please don't worry, I'm not going to harm anyone as I am aware of the consequences and what it does to the art as a respectable way of life when something goes wrong and I want no part of that.

    Is the 1012 in the core going to work OK with the 1018 yoke and a-bar and will this affect the residual magnetism? Also does it matter which direction I wind the wire for the wraps?
    Last edited: Jul 1, 2007
  8. Jul 2, 2007 #7

    The 1012 seems to work fine with the 1018 and it does not matter which way the winds go as long as they both match. I'll post back in the near future with results on residual magnetism and if there is any difference in wear on the parts from the different grades of steel. I just figured I would answer my own questions for anyone else who may be seeking this info. My coils cut my voltage in half. I would imagine less voltage = less heat:smile:
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook