Have you ever wanted to have a string of noisy firecrackers or a
bright, loud and long crackling effect in your fireworks show, but you
didn't because firecrackers were illegal in your state or you didn't want
to spend the money for a large roll of firecrackers? The "crackling
centipede" can give you that effect, inexpensively, using safe
and sane "magic whips". I wanted to have a two minute crackle effect
in one part of a show that I was giving. Firecrackers are illegal in my
state. I used the "crackling centipede" to solve the problem.
MATERIALS
- 11 feet of 18-inch wide aluminum
foil.
- 10 boxes of "Magic Whips"* (12 to a box)
- about 10 feet of fast visco
fuse (1 second/inch burn rate) .
- black electrical tape
- scotch or masking tape
- ruler or measuring tape
- magic marker
Notes on Materials
"Magic whips" are thin, flexible
tubes of cellophane paper that contain small spheres of crackle material. They
are sometimes considered novelty items, so they are legal in many states. They
come in lengths from 10"-30", but the ten inch variety seem to be the
easiest to find. A ten inch long magic whip gives a bright and loud crackle
effect for about 7 seconds. These things, like the classic
"pop-its", go by many different names, including "monster
whip" or "fire krackle". They come in boxes of anywhere
from 3-10.
Procedure
Unroll about two feet of aluminum foil from the
roll, shiny side up! You might find it easier to remove the roll of foil from the
box, but then you will need something to keep it from rolling away. Do not cut
the foil! Unroll about 1 foot of fuse from the roll and straighten it out. Do
not cut the fuse. Lay it the long way, in the middle of the shiny side of the
foil about 12 inches from the end. Starting at the end of the fuse, mark six
dots on the fuse two inches apart. Take two magic whips and bend the fuses, one
inch from the end and at 90 degrees. Lay them down one on either side of the
fuse, perpendicular to the fuse and at the first mark. The bent fuses should
point towards the roll of foil. Many magic whips have a cardboard or paper base
inside the cellophane tube. This base should be down to get the best effect.
Take a piece of black electrical tape and wrap it tightly
around the two fuses of the magic whips and the fuse. Use the methods described here. These are the "legs" of the centipede.
Take
another two magic whips and place them at the next mark (2 inches away) on
the fuse. Attach them to the fuse as you did the first two. Continue adding all
the whips from one box (6 pairs of legs) to the six marks. Make sure the
centipede is centered on the aluminum foil 12 inches from the end. Tape the fuse
at the first and sixth legs. Tape each leg at the edge of the foil. If you don't
want the legs hanging off the foil, you can bend the whips a bit to make them
fit better. See the image at the top of this page.
Unroll another foot of fuse. Mark
six more marks 2 inches apart from the last mark on the fuse. Fold the 12 inches
of aluminum foil over the top of the 12 magic whips. Press down firmly so the
fuse and whips are immobilized. Unroll another foot of foil from the roll. Now add another box of whips to the centipede as you did
before. Make sure you tape each leg at the edge of the foil and tape the fuse at
the first and sixth legs.
When
you are done with the 2nd box, unroll another foot of fuse and add six
more marks, 2 inches apart to the fuse and then fold the 12 inch end of
foil on top of the 12 magic whips and press down firmly. Then unroll
another foot of foil from the roll. Continue this process for nine boxes
of whips. At the tenth box of whips, if you want "nearly" two
minutes of crackle, only put down four pairs of whips. This will make the
fuse 114 inches (114 seconds) to the last two whips. These last whips will
burn for seven seconds, giving you a burn time of 121 seconds. If you
don't need it that exact, use up all the whips. Cut the foil from the
roll. If you are going to use an electrical igniter, attach it now, at the
end of the fuse. As before, fold the 12 inch end of foil over the last set
of whips and press firmly. You should now have a small 18"x12"
foil package. Put the foil package in a garbage bag for storage and
transportation. When it is time to ignite your centipede, remove it from the bag
and set it down on a hard surface, such as asphalt, cement or a board. Carefully
unroll it and then ignite it. Most of the time, 3 pairs of magic whips will be
crackling at the same time. Putting the centipede on the foil serves several
purposes. You only have to work with a two foot piece of foil and centipede at a
time. This will fit nicely on a card table as you construct it. When you are
done, you will have a small package (18"x12" and a few inches thick)
for easy storage and transportation.
Transporting a full 10 foot long centipede
is tricky. If you just put the centipede in a bag without the foil, it will get
very tangled and whips can fall off as you untangle it. The folded foil and tape
keep the centipede legs immobilized and prevent tangling. Lastly, the shiny
surface of the aluminum foil increases the brightness of the flashes and
crackles. Variations: Add crackle balls, crackle ground spinners or crackle
jumping jacks or small strobes at various points along the fuse, to add some
variety. Attach a long enough piece of fuse to these items, so that they can be
off the foil and away from the whips. Attach the other end of the fuse to the
fuse of the centipede. Fold them into the foil package, but unfold them off the
foil when you unroll the centipede.
You can lengthen or shorten the
centipede depending on how long of a crackle effect you need. The total crackle
time will be: (total crackle time in seconds) = (fuse
length in inches) * (1.0 seconds per inch) + (7 seconds). You can put the whips closer together (1-1.5 inches apart)
for more crackling or further apart (3 or more inches) for less. Don't put them
more than 7 inches apart or you will have a lull in your crackle. You can also
use normal visco fuse (burns 2.5 seconds per inch), which will give you a
shorter centipede and you will need fewer whips. Don't put them more than 2.8
inches apart or you will have a lull in your crackle. For a 2.5 inch per second
fuse (visco type) the total crackle time is: (total crackle time in
seconds) = (fuse length in inches) * (2.5 seconds per inch) + (7 seconds).
For more crackling effect use fuse with a faster burn time
(0.5 seconds per inch) or use longer magic whips. Then more whips will be
burning at any given moment. For 0.5 seconds per inch fuse, the 1.0 or 2.5
seconds per inch, in the above equations would be changed to 0.5 seconds per
inch. For longer whips, the "7 seconds" in the above equations would
be changed to be the burn length in seconds of the longer magic whip. Below are
some pictures of an ignited four foot normal visco centipede with
spinners. Click
here to see a video clip.
