By Richard Howell Kevin Ryland Christopher Cox Yihan Pang Bryce Langlotz
Our design that we are choosing to create is a rail-gun transformed to become a launcher for plans off aircraft carrier. This is unique in that instead of trying to shoot the projectile as fast as we can, as we would with a gun, we are trying to control the speed and the angle to allow the pilots and planes to function safely once the initial power is lost.
The major difference between a rail-gun and a regular gun or launcher is the lack of a propellant. Since the main force behind the device is a magnetic field, not explosions take place. This makes the project relatively safer than many other types of launchers.
The idea as created by a french inventor names Louis Octave Fauchon-Villeplee. He filed this patent on the first of April in 1919, and it was issued in July 3 years later. The orginial name of the rail gun was the “Electric Apparatus for Propelling Projectiles.” This name was shortened to “rail-gun” later because the rails that are the main section of the device. This idea was not immediately used anywhere as everyone thought it was unsafe.
This idea was found by German Ordnance Officer Joachim Hansler but these guns were never built as these theories were finally defined enough to allow the construction in late 1944. By this time the Germans were on the defensive and could not spare the resources to make a prototype.
In 1947, a report was done proving that the only problem the Germans would have had was that each gun would have needed more power than is currently being used by Virginia Tech. In 1950, Sir Mark Oliphant build a 500 Megajoule Homopolar Generator that was used as the power source for a large scale rail-gun that was build and was used as a instrument of research and science.
Safety is paramount in this project. While we are creating a launcher we only launch under very controlled circumstances. Heat is also a main issue. The electric current going through the wire will create so much heat that the rails might melt. This is why we are using aluminum which does not melt as easily as other metals would. We also need both the rails and the Projectile to be conductive for this launcher to work. This means the material that can be used are limited.
We researched online and found different sites which showed us the fundamentals of the rail- gun and took different ideas for our own. We also decided we would make this gun relatively small to other rail guns. This will just be a model type thing not the real large scale launcher.
We decided as a power source we would store energy into capacitors taken from old disposable cameras, there are very weak so we used many of them, wired in parallel. As a base we decided to use wood for price reasons. For the rails we used aluminum because it does not melt easily and conducts electricity very easily. For the wires we used basic wires and we used a bread board to wire it all together.
We put all the wires and sauntered thread wires to solid wires on the bread board to connect all the capacitors in parallel. We cut the base to be a triangle set up at an angle of 45 degrees to get the max distance from our shot. To do this we found that we had to cut our 18 in boards so that the base and height is 12.7in, while our slanted board can stay 18inches.
Doing the original calculations we did consider the thickness of the boards. There was a problem with the wires the first time we set up the bread board, we rechecked the wires and found one was misconnected. We had a problem with getting the current to discharge. The indicator light showed up so we knew the charge we there we just could not get it to discharge. The energy from the source is being dissipated by the length of wires. The nail is being welded to the sides of the aluminum rails when we discharge all the electricity. There is a problem with one of our two switches we believe. The Projectile was the wrong material.
For the problem with the dimensions, we premeasured the dimensions and re-evalutated the lengths. For the problem of the wires we took out the capacitors and checked and found a disconnect in the wires. For the problem of discharge we took out the switch to test if that was the problem and found a disconnect from switch to board. We changed the projectile to aluminum. We positioned the projectile in different ways and tried different sizes but could not get it to shoot yet.
With our first test we got a spark across the nail. The nail was blackened by the shock and seemed to be melted into the aluminum slightly. The nail was harder to get out than before.