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Registered Member #55
Joined: Thu Feb 09 2006, 04:56AM
Location:
Posts: 149
You might have chosen the wrong accleration implement for the purpose of your experiment. If your overall goal is to provide some sort of scaled data for launching items into orbit using electromagnetic accelerators the railgun would not be a good choice. Think about the tremendous forces the cargo of a railgun fired vehicle would experience. Remember Newtons first law? As Yohan and I discussed on the old forum, and this is why we felt switched reluctance systems would be better, you need gradual acceleration. A coilgun would be better suited to your study, not to mention you could build a decent coilgun with what you have. Now if someone could just break the dang 100m/s barrier. William
Registered Member #135
Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735
Check out my EM Ring Toss. Real easy project build, good results, 22 f.p.s rougly, 160J.
Uses 3 power supply caps, I think 6800uF at 450VDC each. You need over 120J for respectable results in my particular application. I dunno about a thin ring, that's much easier to move, but the coil would be smaller too.
Anyway, Takes about a day to build, and then you're on your feet.
Registered Member #167
Joined: Mon Feb 13 2006, 06:41PM
Location: Waterloo, WI
Posts: 54
I would not get too discouraged. a small scale railgun is doable, but you need to get some caps! As there is not really such a thing as a small scale railgun :) If you are just doing it for a school, I would stick with photo flash caps. they are free, and all you have to do is ask for them nicely. Tell them it is for a school project and I am sure they will help you out, do not say much more than that however, telling them you are building a coil/railgun will not help your cause. I am sure you can get 25-50 of them with very little problems.
Remember current is king in a railgun, and the more caps you have in parallel the lower your ESR (resistance of your caps) http://wiki.4hv.org/index.php/Capacitor
next off use a very very very very light weight Aluminum projectile, or perhaps use aluminum dust and do a plasma armature.
also there are many selling caps on this board. 5-10 bucks a cap,
Registered Member #106
Joined: Thu Feb 09 2006, 09:39PM
Location: Portland, OR and Istanbul, Turkey
Posts: 47
Here is another link to the Wiki. It is a page showing what has different types of electrical components and parts that you could scavenge for projects. TV,s Radios. All sorts of stuff. Actually it's a good page we should all try to expand a bit.
Registered Member #161
Joined: Mon Feb 13 2006, 03:15AM
Location:
Posts: 20
Holy crap...it's Jason Rollete. I like your work if you haven't noticed. Anyway I'm considering getting six of ...'s pulse caps. That would bring me in at a little over a thousand J's right? I think my bore will be a half inch and my 6" rails will be made of copper w/ some type of strong plastic holding it together.
Registered Member #167
Joined: Mon Feb 13 2006, 06:41PM
Location: Waterloo, WI
Posts: 54
Hahahaha that is funny. Well I like doing railguns, and talking about them. Those seem like ok caps and the price is right. I am not so sure you will want a ½†bore for that small of a bank. maybe .25†would be better. Also when building your rail you might want to consider how you are going to switch the power? Is it an armature switched design? Or scr? If armature you need to have some type of air injection. And you rail need to take that into account for rail design. Also if you are considering a multiturn rail? If not you might want to make you rail co you can do it later to test it.
Registered Member #161
Joined: Mon Feb 13 2006, 03:15AM
Location:
Posts: 20
Yes, I want my armature to be injected into the rails. But does it have to be via air? You know when playing pinball the thing you pull back to launch the ball? What if I made something like that, that would use the same amount of energy each time? I don't know much about Coil guns...but couldn't they potentially be used as an injection mechanism? I'm not going to try and build a coil gun right now as I am currently...already short for time I am just asking.
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