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Registered Member #158
Joined: Sun Feb 12 2006, 09:53PM
Location: Central Ohio
Posts: 282
Simon wrote ...
This is interesting work. Do you have a particular application/goal in mind?
Well not really, but sort of. We always have a goal of 'just making something that works' right? But as a 'gun' that shoots a projectile it should be accurate. As I said above I would like to be able to shoot squirells off my birdfeeder, that would make it really worth while I really started this thread just to strike up some new conversation on cg's, and accuracy really hasnt been talked about much. My tentative plans are to build a simple 1 stage test gun were I can try different triggering, coils, projectiles, etc. Then when I get a good idea of how to build a good one I would like to make either a riffle or a handgun depending on resources and capabilities.
Registered Member #90
Joined: Thu Feb 09 2006, 02:44PM
Location: Seattle, Washington
Posts: 301
Great plan -- I would love to have a computer-controlled squirrel-killer in my back yard.
I know that my web site illustrates a projectile with fins, but this is just a concept. Once my coilgun achieves enough speed to need fins, I'll use something like soft foam or spring-loaded fins. The "long string tail" sounds like an easy-to-build stabilizer, too. I wonder if it would work at supersonic speeds?
Registered Member #75
Joined: Thu Feb 09 2006, 09:30AM
Location: Montana, USA
Posts: 711
Regarding the induction vs. reluctance matter: Induction coil guns need high voltage pulse caps, so they are out of the reach of most amteurs. Reluctance coilguns can be made to work quite well with photoflash or similar electrolytics, so everone can have a go at them. Efficiency-wise I think the induction type takes over once you reach energys of more than a couple of 100J input energy. You should really be talking to Thomas "pulslaser" though, he is the only one I know of who ever build an induction gun.
Registered Member #158
Joined: Sun Feb 12 2006, 09:53PM
Location: Central Ohio
Posts: 282
Ok, so induction coilgun = harder to scale down to photo-flash cap levels and less efficiency at these lower power levels. Perhaps more difficult to trigger because the pulse needs to start when the projectile is already at the midpoint of the coil. Maybe I'll talk more about the induction cg's in another thread later. But anyone with some new ideas on improving accuracy or simply reporting there accuracy with a coilgun I would like to know so post it at any time.
Registered Member #1208
Joined: Thu Jan 03 2008, 05:30PM
Location: Chesterland, OH
Posts: 154
1 sort of idea for a projectile: a drill bit. heat it up and anneal it( so it doesn't shatter) and just design everything around that.
pro's: spins hard pointy (extra penetration
gives an air gap (big) had more drag expensive (kind of) has to be cut and annealed hard to recover (might go through squirril) hard to clean (you might have to pick squirril guts out of the "trenches" (not sure what they're called)
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coilguns...accuracy?
I really started this thread just to strike up some new conversation on cg's, and accuracy really hasnt been talked about much. My tentative plans are to build a simple 1 stage test gun were I can try different triggering, coils, projectiles, etc. Then when I get a good idea of how to build a good one I would like to make either a riffle or a handgun depending on resources and capabilities.
