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Ballistic Stabilization

A project log for Coil Gun/Gaus Cannon

A device that uses electricity to propel a projectile at a significant speed.

jeff.ballard.86jeff.ballard.86 05/06/2014 at 20:535 Comments

So I trimmed out my back door today, and then decided to make something for my coil gun.

I purchased some .5 id .625 od poly-carbonate tubing a while back, along with a little 6v motor.  So I 3d printed a motor mount and a magnet mount (attaches a magnet to the end of the motor shaft.)

The motor mount has a hole that I will thread with a 8-32 tap and it will except a threaded rod to be used as repositional stop so I can test projectile placement in relation to the coil.

The projectile will attach to the magnet, the motor/projectile assembly will then slide into the barrel, motor will spin up, coil gun will fire, and hopefully will have a stable ballistic path.

I also printed out some new coil endcaps that will also be used as my new photo gates.  I expect to push nearly 4000 amps through each of the new coils, I am also hoping to reach projectile speeds in excess of 500 feet per second.

Discussions

jeff.ballard.86 wrote 05/22/2014 at 14:54 point
Im just using multiple online projectile energy calculators, they all give me the same number.

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dave.m.mcdonough wrote 05/07/2014 at 23:09 point
Interesting idea.. and that's quite a bit of speed! How much does that projectile weigh?

Has accuracy been an issue? Some before/after data sets are definitely in order for this mod. :)

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dave.m.mcdonough wrote 05/07/2014 at 23:26 point
You said output of ~80J so I think just under 7g to be at 500fps? The bearings I'm calculating mine with are 8.402g, so at 80J output it would be around 450fps (81.4J 139m/s). Asuming I didn't mess up my spreadsheet somewhere..

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jeff.ballard.86 wrote 05/21/2014 at 17:48 point
My projectile weight is just over 30g. It is .5" diameter steel rod @ 1.25" length.

Accuracy for my projectile has been horrible, in some cases the projectile would hit the target sideways. you may not have to worry about this with your cylindrical projectiles.

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dave.m.mcdonough wrote 05/22/2014 at 12:23 point
30g? man. I hope my equations aren't fubar, my numbers coming out of the spreadsheet are much different. I'll have to review things.

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