# Need help w/ making my own Rail-Gun

1. Sep 22, 2009

### dannybill

I started on this as my English 10 Speech class "How to Speech," but am now making my own without time restrictions,and not for a grade or for school(so it's not Homework anymore.) My main problem is that, although I aspire to be a physicist & Engineer, I lack the necessary knowledge to do this by myself. I'll make a list of what I know, so that I can get right to the stuff I need to know;

-Rails MUST be both electrically and magnetically conductive.
-The wires I intend to use for the power source (wires around a wirespool) should make as much electric charge when high-power magnets are moved around them.
-The rails must be held firmly in place, as the magnetic force and kinetic energy of the projectile being launched will try to force them apart.
-The projectile must be conductive, as well as the object holding the projectile, which also completes the circuit between the +Rail and the -Rail.

That's what I know,but what I'm not sure about are the following;

Q1.Do the rails have to be contained in an insulating box to reduce the possibility of an ambient discharge into me or a nearby object?

Q2.In truth, I'm sort of lost on the mathematics part of this experiment. I could just do Trial & Error, but it's to dangerous an expirement for that.

Q3.If I were to use, say, a clacker-ball (the tiny metallic ball-bearings usually seen on strings, and you pull one to one side, let it go and the kinetic energy transfers to the ball on the other side,) what would be the formula to tell how strong the electrical charge would need to be to launch the ball?

Q4.I know the best heat insulator is a vacum, but as I'm simply a middle-class Highschooler, this isn't a very probable notion. Whats the best thing that would be available at, say, an Ace Hardware, Home Depot or Lowes?

Q5.And finally, the biggest question. What are the main precautions i should take? Be in a different room, have protection over the camera, aim the Rail-Gun at something like a pillow? Safety is the most important thing, because if i get injured severely by a teeny-tiny clacker-ball and end up not being able to be a String Theory Physicist, that'd be pretty lame :rofl:

2. Sep 22, 2009

### seycyrus

Where are you getting your idea about what a rail gun "is"? Some source on the web? A video game?

Giving an idea of what sort of set-up you were considering would help people help you out.

3. Sep 22, 2009

### Staff: Mentor

Welcome to the PF. Two suggestions for further reading. First, click the Search link at the top of the page, and choose Advanced Search. Then enter Rail as the search word at the left, and select Search in Titles. This will give you a list of similar threads here at the PF (plus some other non-helpful hits like Light Rail).

The second suggestion is that you go to wikipedia.org, and search on Rail Gun. That should get you a basic intro article to help you out.

There is a difference between giving a speech about rail guns, and actually building something yourself. There are lots of safety aspects (electrical, mechanical, etc.) involved, and you really need an in-person advisor or mentor to make sure you make it to your future...

4. Sep 22, 2009

### dannybill

Yeah,I probably should have looked for other threads about my topic, I know it's a fairly common one. I dunno, I just never really look in other threads as much. I figured it'd take less time to post a topic that specificly addressed my question, than looking through ther topics... Also, for some reason, as I'm typing this it sounds sorta pompouse(if thats how its spelled,) or like I'm being sarcastic, so please don't take it that way. But in reply to seycyrus; I'm not talking about any "Big Time" project that I'll be bringing to some huge Science & Engineering expo, just something for fun. So it'll be basic. 2 rails, the armature, and most likely a wirespool that wouldnt cost a lot, and wouldnt have an excessive amount of wire on it (so nothing like 100 meters of wire.) I've made a rough sketch of what I'm thinking the design will be, but I don't think it'd help much to copy it into this topic(if that option's even enabled.) So think of it more as Pure Expiremental Research. I'm not trying to test this as a prototype to some revolutionary Rail gun, it's just for the sake of knowledge (and fun.)

5. Sep 23, 2009

### Staff: Mentor

Fair enough. Read the other PF threads and the wiki article, and post specific questions here.

6. Sep 23, 2009

### vk6kro

We seem to get a rail gun post every few weeks.
It always works out that you need absurd currents and lethal voltages and lots of money to get anywhere.

If you just want to see something move very fast, put a slider on a rail and put a horseshoe magnet above and below the slider. Then use Fleming's left hand rule to predict the direction the slider will move.

Works fine, but the slider gets pitted and corroded quickly with the current.

7. Sep 29, 2009