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Coil Calculator

  1. Apr 5, 2014 #1
    Hey guys! Not sure if this is the correct place to post this, but this seemed the most relevant...

    So I'm working on a coilgun to shoot 45mm steel spheres, but I need to figure out how long [diameter, gauge, etc] my coil needs to be.

    I want to generate a force of about 5 Joules or more [preferably more].

    Using "magnet wire," what gauge, # of turns, do I need?

    The distance between the ferromagnetic material and the solenoid will probably be between 0.75mm-1mm, depending on the size pipe I can find [else I might need to make my own].

    Thanks in advance for any help!

    EDIT: I gave distance from the top of the projectile to the bottom of the solenoid. ;)
     
    Last edited: Apr 5, 2014
  2. jcsd
  3. Apr 6, 2014 #2
    First of all you have to calculate the force from energy [5 Joules].
    The energy E=mass*speed^2/2
    mass=Vol*specgravity
    Vol=4/3* PI()*r^3
    r=45/2=22.5 mm [2.25 cm]
    Vol=47.71 cm^3 mass=7.81*47.71/1000 =0.372 kg.
    speed=sqrt(2*E/mass)=5.18 m/sec
    For a time of 0.3 sec acceleration will be: speed/time=17.28 m/sec^2
    Then the force will be F=acc*mass=17.28*0.372=6.43 N.
    Now you can continue following [for instance]:
    http://trg.fke.utm.my/members/dahiru/Journals_published/Journal_Elecmag_Gjet.pdf
     
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