F.O.P.W. Part 3 - Fiber Optics
So, you want to send light through a cable,
***any*** length, around corners, up or down grade?
Well, this is the product for you.
The inside wall of fiber optic cable acts like a mirror.
Light is reflected along its entire length up to the point
where the cable is cut, kinked, or otherwise terminated.
You'll find many options when searching for fiber optic cable.
New, surplus, used, and pre-assembled special cables are the most common.
I elected to do business with the Fiber Optic Store. This website was quite
helpful in deciding which product I would need.
I bought single strand cable in a few different diameters.
(.25 mm., .5 mm., .75 mm., and 1 mm.)
Obviously, the larger diameter cable will appear brighter when lit,
but I am also concerned with flexibility. Fiber Optic cable looks and
behaves a lot like monofilament fishing line.
I will be using four strands of .5 mm. cable in each length of tubing.
That's right... IN each length...
I considered fastening the fiber optic
cable to the outside of each tube
with narrow strips of (black) gaffers
tape, or possibly painting a little
bit of liquid latex over the cables.
I believe running the cables inside the tubing will be better for two reasons.
1. I won't have to worry about the cables separating from the tubing.
2. Fiber optic cable is sort-of delicate. The tubing will protect the cable.
As seen in the photo above, I forced a wire (guitar string) through the tubing.
Bend the wire hard, then insertthe fiber optic cable(s) through the bend.
Remember to allow a little extra cable
for this bend. Once you put a hard crease
in fiber optic cable, the light will "stop" there.
On the same topic - be sure to cut the
cable "long." because splicing is out of
the question. It's easy to cut off any excess.
Tape the wire to itself, making sure tocompletely tape the "loose" end.
(If you don't, it could snag during pulling)
then tape the cables to themselves.
This is exactly like the "fishing" trick
electricians use to feed wires through
walls, floors, etc.
Carefully pull the wire through the
small hole in the latex tubing.
And there you have it...
Four 1/2 millimeter, single strand
fiber optic cables inside a length
of latex tubing.
The cables exit the tubing before
the threaded brass connection,
so air flow won't be a problem.
The small hole you just made in the
latex tubing is most likely self-healing due to the elastic properties of latex,
but I sealed the holes with a little bit of hot glue. (liquid latex might be a
better product to use for this task.)
Now it's time to light 'em up.
Now, before you laugh too hard...
This is my "Proto - Light Box."
I need a light source (light bulb) and some method
of attaching the mass of fiber optic cables to a leak-proof
light box. Think about it - A 60 watt light bulb would probably
spoil the dark hallway scene...
Left to right:
Single gang metal box..........................................................holds the light socket.
Light socket from a motion detector light kit...........................holds the light bulb.
Coffee Can......................................................leak proof light box (except the lid)
Bright Half of a cheap flashlight (bulb removed)...attach the cable to the light box.
This did the job. It helped me test the different diameter
fiber optic cables I bought. I also tried a few colored gel sheets.
I quickly built an improved, smaller, and most
importantly - less visibly offensive - light box.
Since this effect will be used with anevent control timer, the pneumatic
and lighting systems will only run for
a short amount of time
(about 3-4 seconds.)
This will help conserve air,
and I'll be able to startle a few guests
in the same group (...cool...)
Left to right:
4" p.v.c. cap
light socket (standard incandescent light bulb -screw base)
60 watt light bulb
4" p.v.c. thin-walled pipe
4" p.v.c. cap
flashlight cap (the part you un-screw to replace the batteries)
flashlight lens and red gel sheet
flashlight reflector with light bulb removed.
I will use p.v.c. for this light box because the light bulb
will only burn for a few seconds at a time.
I would never run a light bulb continuously inside
a p.v.c. housing.
You'll need to drill three holes in the (left) 4" p.v.c. cap.
(2 for the socket mounting bolts, and one for the
wire to power the light.)
In the other (right) 4" p.v.c. cap I drilled a hole
large enough to accept the flashlight cap.
(snug fit... remember - leak proof.)
At right you see the junction ofthe fiber optic cables and the light box.
I taped the groups of cables together to
make them easier to handle.
The bundle fit loosely in the hole
where the flashlight bulb was removed.
Some hot glue or epoxy will work well
to fill this gap.
I had to cut the flashlight handle. If not for this short
section of handle, the reflector and lens would have to be glued
to the cap. ( I want easy access to the colored gel sheet.)
If you don't want to destroy an otherwise perfect two-dollar flashlight,
you could certainly drill a small hole in the 4" p.v.c. cap, and attach
the fiber optic cables directly.
My plan here is to use the flashlight reflector to compensate for the
amount of light lost to the colored gel sheet.
I don't know if I was successful, but it made me happy.
The 4" p.v.c. caps are semi-translucent when lit from the inside.
A black paint job will fix that problem.
Below is a photo of the finished "fiber optic" part of this project.
(almost done.)
