Posted on 08/12/2014 9:16:51 PM PDT by Utilizer
Homemade Railgun Experiment Yes, that's right. After gathering all the materials I built my first little railgun experiment.
Read the whole article after the break!
Let's first take a look at how a railgun works, a video about the whole topic can be found here. Similar to a coilgun, a railgun works by magnetic propulsion. A basic railgun consists of three parts: A set of parallel, metal rails, a huge powersource like a capacitorbank and a metal projectile. Here is a railgun's schematic for your convenience.
What happens inside a railgun? There's a huge current flowing through the rails and the projectile at the same time as shown in the illustration. Every current, or on a smaller scale, every moving charge creates a magnetic field. Take your right hand and form a fist - thumb in the current's direction - your fingers now indicate the magnetic field lines created by the current in your thumb's direction. Why is the projectile moving then?
According to Lorentz's law, every charge (red current) moving in a magnetic (blue) field experiences a force (green). So basically the magnetic field emitted by electrons travelling on the rails propels the projectile. Before we will take on real railguns let's do a small scale experiment first.
(BREAK)
(Excerpt) Read more at doityourselfgadgets.com ...
I just wanted to post this to get more information from some of the gunsmithing and hobbyists fanatics as to how they might think about improving this design past its research phase.
Obviously, aluminum despite its high conductivity has too low a melting point to be used as a succesful projectile. So too, unfortunately, is lead.
Any other suggestions?
“Any other suggestions?”
Depleted Uranium...
titanium, but its bloody expensive.
Price and resistive coefficient too high, plus availability is practically nonexistent.
washers, slugs, bb’s, all are used in railguns.
For low-power devices, yes I can see that. For a device that can accelerate a projectile past the slingshot-speed range, some of the comments on the article page show that they are not really very practical, since they very quickly weld themselves to the rails instead of becoming useful projectiles.
Beat me to it...
tungsten probably would be good. It weighs about the same as gold and has a high melting point.
Ping to railgun fun
What about resistivity compared to standard copper, and price compared to something like stainless steel, or perhaps chrome-plated slugs?
We ARE talking about something that would be workable from a hobbyists or gunsmithing bench, or at least that is why I posted the article. Something that anyone with some decent tools, preferably not demanding something greater than a small machine shop, might be able to construct.
Plus, I am not sure how available tungsten is or how expensive it would be to purchase and experiment with.
A galvanized finishing nail might work
Enjoy!
https://www.youtube.com/watch?v=mdZo_keUoEs
Usually I can put politics aside to gain some knowledge, but this guy starts off with too long an anti-American, anti-firearms rant for me to watch it, let alone enjoy it.
It didn’t seem to me to be that way. Oh well.
Thanks for that assessment. I am normally quite reluctant to click on links for unknown vids since without corroborating statements as to its validity I always consider them to be propaganda pieces at best. I thought I might look at it briefly later if other FReepers knew about it and could verify a valid perspective, but your post simply makes it clear that I do not need to waste time and bandwidth to follow that link.
Bookmarking
Try steel ball bearings for projectiles, that is what I see used most often with railgun projects.
The real issue that you will run into is that you need a whole lot of power to hurl that projectile with enough force to do anything significant. Chemical propellants simply outclass railguns when it comes to efficiency.
Tungsten is a very poor conductor though, hence its utility in light bulb filaments.
I now have a new favorite pasttime. Oh boy!
Looks like something fun to try to build.
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