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Registered Member #1842
Joined: Wed Dec 03 2008, 03:10AM
Location: Central Minnesota
Posts: 3
I had a thought last night. I was wondering if anyone thinks that if you where able to have a projectile that has a magnetic polarity, so it gets pulled forward, and then just past the half way point you could reverse polarity of the coil to push the projectile away? I am not sure if this is possible. I decided to post up to get input from people more informed than i am on this subject.
Registered Member #1633
Joined: Tue Aug 12 2008, 04:21AM
Location:
Posts: 45
is it possible: sure might it increase efficiency: maybe is it easy to do: no that quickly collapsing magnetic field will create quite a large emf spike, which might damage whatever driver you use, but it might work if you put enough thought into it. just make sure you don't end up permanently magnetizing the projectile.
Registered Member #1132
Joined: Mon Nov 19 2007, 06:15PM
Location: Slovenia
Posts: 84
Yes the coilgun poducees amazingly strong fields that like to magneize iron.Meaby if you fire a neodium magnet as a projectle, but the magnet will shater to pecis on inpact with the target. Permanent magnets are generaly easy to break and you cant use a magnetised nail or something cause the coilgun will magnetise it oposite
Registered Member #1694
Joined: Sat Sept 13 2008, 09:13AM
Location: Australia
Posts: 108
Berni wrote ...
Yes the coilgun poducees amazingly strong fields that like to magneize iron.Meaby if you fire a neodium magnet as a projectle, but the magnet will shater to pecis on inpact with the target. Permanent magnets are generaly easy to break and you cant use a magnetised nail or something cause the coilgun will magnetise it oposite
I'm not sure if what im saying is right, but I'm sure someone will correct me. If you load the magnet so that its north pole is facing the south pole of the coil, it will work 'ok' but the projectile would probably saturate and not experience the same amount of acceleration as a normal piece of iron. If the magnets south was facing the coils south, it probably wouldn't fire at all. If it did, there would be some pretty major hysteresis losses.
Registered Member #537
Joined: Sun Feb 18 2007, 07:22PM
Location:
Posts: 10
Yeah, I've stuck some neodymium magnets in my coilgun. Doesn't work too well. Cold-rolled steel is much better in my experience. I can't even dent sheetrock with neodymium magnets. I agree that it may have something to do with the saturation point of neodymium
Registered Member #1694
Joined: Sat Sept 13 2008, 09:13AM
Location: Australia
Posts: 108
I think a laminated iron projectile, or a projectile made of powdered iron & epoxy or something would be the best projectile. Iron has a high saturation point and the laminations/epoxy would minimise eddy current losses.
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Theory for increasing power of coil gun
