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I want to use small cylindrical magnets which are axially magnetized for projectiles. Good idea or bad? Will earths magnetic poles affect it much and cause it to spin too much?
Registered Member #968
Joined: Fri Aug 24 2007, 04:54PM
Location: Norman, Oklahoma
Posts: 104
You probably will find iron,steel, or a nickel, or a silicon alloy to be better. I would stay away from "magnet" alloys such as magnet tool steel. As mentioned in the coilgun wiki page(projectile saturation section):
" Limits imposed by projectile saturation In short, even when the armature is saturated, force still increases with coil current, albeit at a slower rate. Where the diminishing returns come in is with the losses. When the armature is not saturated, force and coil loss follows roughly the same I2 law. When the core is saturated, armature force goes as I and loss still as I2...so as you increase coil current beyond a certain point, efficiency degrades when energy losses outstrip energy transfer to the armature. This is why multistage launchers are always advantageous...." Reference:
I'm not sure what to expect in terms of spin. Spin can be a good thing as it can aid in projectile stabilization, but it represents some energy not transferred to linear acceleration. This will obviously make efficiency calculations complicated and you will be underestimating your efficiency otherwise.
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Magnets as projectiles?
