The document describes a student project to design a small-scale model of a rail gun to launch projectiles. Rail guns use magnetic fields rather than explosives to propel objects, making them safer than other launcher types. The students researched rail gun fundamentals and designed a prototype using wood, aluminum rails and wires, and capacitors from disposable cameras as the power source. Initial tests showed sparks but the projectile did not launch due to issues with dimensions, wiring connections, discharge, and projectile material. Further troubleshooting is needed to optimize the design and successfully launch a projectile.

1. By Richard Howell
Kevin Ryland
Christopher Cox
Yihan Pang
Bryce Langlotz

2.  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.

3.  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.

4.  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.

5.  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.

6.  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.

7.  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.

8.  Some of the major formulas used are an
applied use of the Biot-Savart law which deals
with the magnetic field that will be generated.
This law states that a magnetic field at a given
distance, x, from the current carrying wires
with a distance between the rails, d, with a
permeability constant, 𝝁, rail radius, r, and
current amps, I, is
B(x)=
𝝁𝐼
4𝝅
(
1
𝑠
+
1
𝑑−𝑠
)

9.  We can assumed that r, the radius of the rails,
is very small in comparison to d, the distance
between the rails. With this assumption we can
have the formula
 Bavg=
1
𝑑 𝑟
𝑑−𝑟
B(x)dx=
𝝁𝐼2
4𝝅𝑑 𝑟
𝑑−𝑟
(
1
𝑠
+
1
𝑑−𝑠
)
 The Lorentz force law(F=IdB) formatted to our
formulas gives us
 F=
𝝁𝐼2
4𝝅𝑑
ln
𝑑
𝑟

10.  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.

11.  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.

12.  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.

13.  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.

14.  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.

15.  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.