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Building an efficient coil gun for photography.

  1. Sep 9, 2013 #1
    I have been doing various experiments with my photography and recently built a coil gun.
    I simply pulled apart a starter-motor solenoid and wrapped the windings around an 8mm tube and fire a short piece of a bolt out of it using a charged 3300uf capacitor and an SCR.
    None of this is calculated but it works pretty well.



    I have a video shot at 400fps showing how it shoots something I want to photograph.
    I use the pre-flash of the camera to trigger the shot and a fraction of a second later I capture the image.
    So my real question is how I can make it as efficient and powerful as possible with what I have, besides perhaps making a better winding.
    The capacitor is rated at 400 volts and 3300uf though the old flash I am using to charge it only takes it up to 325 volts at full charge.
    The electrical burst mustn't last too long or it will pull the projectile back again.
    I am using an 800 volt 300 amp SCR to trigger it using an optic sensor used for triggering flash.
    I was thinking that perhaps I could make the coil much longer to give a longer pull stroke on the projectile but am unsure of the maths of this like number of windings, thickness of wire etc.
    Any help would be appreciated :)
  2. jcsd
  3. Sep 9, 2013 #2


    User Avatar
    Science Advisor

    Unfortunately building coil guns is deemed far too dangerous for the PF.

    You should have couched your question in terms of the physical electronic circuit requirements without mention of application to coil guns. You are actually building a magnetic impulse generator.

    The trajectory of a bullet or missile, or the reason why guns are designed the way they are, seem to be OK questions.

    If you google the subject of your interest you will find plenty of amateur assistance from other sites. Because you have an enquiring mind, your post will now have to be reported as a dangerous activity.
  4. Sep 9, 2013 #3


    User Avatar

    Staff: Mentor

    Thread closed. Nice pic, BTW. :smile:
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