Transcript How to parachute a teddy.

How to make a teddy
parachute.
Number 2 in the series by
Arthur Dibble
(and the Ted Berets)
November 2007
In conjunction with the web site
www.tedberets.co.uk
WHAT ‘CHUTE
The following notes are based solely on my own experience gained
over a number of years of bear bombing under the tight
regulations of the BMISS and apply only to the "Sport" of
dropping small, furry inanimate cuddlies (known as Para-fauna or
Para-flora and more recently Para-fungi) from high altitudes
lofted by a kite, or on windless days from any suitable high tower
or building. Information and pictures from this presentation can
be found on my web site.
There are many different types of parachute in full size and with
Teddy bears we try to simulate most of these. One of the added
advantages in the small versions is that you can let your
imagination run wild and make all sorts of shapes which will slow
the decent of your bear.
WHAT ‘CHUTE
•
The first and most common
type is the Hemispheric or
mushroom 'chute which is easy
to make and works well no
matter how inaccurate your
cutting and sewing. As they
are so easy to make a large
range of sizes can soon be
produced for different
weights of bear and varying
wind speeds using the gore
calculator we will look at later.
Whilst decent rate is
controlled mainly by overall
area the central vent hole has
a large effect. If no hole is
left the 'chute will oscillate
rapidly during decent.
WHAT ‘CHUTE
•
The type of 'chute used in
human displays regularly seen
at shows is the ram air type.
These are very efficient and
can be steered well. They are
however very complex to
make in the bear size and
although they look fantastic
when deployed I have found
them problematic. Good plans
are available in the
Barker/Andrew publication
The Big Book of Parachuting
Teddies and I have seen
these work superbly even in
the Poulter/Swift scaled
down versions. The new Swift
RC version is awaited with
baited breath.
WHAT ‘CHUTE
•
A relative newcomer to this end of the
market is the Low Aspect Ratio Annular
(LARA). I have designed this from some
photos The BOF published. It is used by
hang glider pilots, amongst others, as
their reserve due to its small volume
packed relative to its drag. The easiest
way to describe it is as a ring doughnut
cut in half cross ways.This still leaves a
stabilising hole through the centre but
the scooped air is trapped. Another
major benefit is that the gore sections
are such that the top and bottom are
inverse of each other and can
therefore be cut alternate ways up
leaving no waste material. Plans are
available on the web site suitable for
fauna of about 6 oz in old money.
WHAT ‘CHUTE
• A recent addition to my
collection is the Fast
Deploy 'Chute as tested by
NATO over a French lake.
I have had to draw this up
from very vague photos so
although the result looks
good it is not that fast
opening. Plans for this have
been published in Kite Flier
and are available on the
web pages.
WHAT ‘CHUTE
•
•
•
•
We now come to the realms of fantasy that
includes The carochute used for aerial bunnies,
The Witches Hat by Doug Manners and Flora
the air born sunflower from the house of Swift.
Others that come to mind are the spinning
'chute from Sky Bums, or a simple steamer
which does slow the decent a little provided it is
long enough and the fauna is light enough. The
easiest of all to make if you are away from the
necessities of life is a simple square of plastic
with a string in each corner.(known as yes
Johnny of course granddad can do that)
The final and most important one we use is the
emperors clothes designed for Telly Tubbies,
fluffy snakes, rats and especially annoying little
sisters.
Free fall sky diving can be simulated by using
very long rip cords but make sure the kite is
high enough.(speak to Steve B about this
defect) The same applies to bungee jumping but
please use a dummy not a bear until you have got
heights and weights correct.
MAKE STEP 1
• Having weighed your bear go to the gore calculator
and try a few diameters to see how close you can
get to the recommended weight. Next decide on
the number of gores (sections) you wish to use. A
guide is always 8 or more, an even number and the
bigger the chute the more gores should be used. I
start at 8 for a 0.5M diam, 12 for 0.75 and 16
minimum by the time I get to 1M. Now submit the
program and print out the results.
MAKE STEP 2
•
On a sheet of thin card mark the
heights up the vertical edge then
horizontally the half gore width. When
this is completed draw a smooth line
through all these points and cut out
the half gore template. Again on the
thin card draw a vertical line
perpendicular to the bottom edge. Line
the straight edge of the half gore
template with this line and draw round
it. Then turn it over, align the straight
edge to the line and draw around it
again. This should now give you a full
gore template with both edges
identical. If you are only going to make
a few 'chutes you can continue with
this card template but if you intend to
do a number I would advise
transferring it to a thin ply wood
sheet.Mark the template with diameter
and number of gores for future use.
MAKE STEP 3
•
Choose the colour material you are going to
use. It is best to use unproofed ripstop as
it's porosity gives it a better flight and it
deploys more readily than proofed. This
can frequently be obtained from kite shops
as rolls of standard ripstop are sometimes
not proofed all the way to the end.
However standard proofed ripstop works
OK. Genuine parachute silk is excellent but
is very difficult to work. Use some bright
colours as these are easier to see if the
‘chute drifts a long way and make sure you
use more than one colour as some show up
better than others against differing
backgrounds. Layout the material flat on
your cutting board and put the template on
top either vertically or horizontally along
the weave. Keep all future parts in the
same direction. Cut round the template
using a hot cutter. (this saves having to do
a double seam later). Turn the template
over (this saves wear and tear) and top to
bottom (this saves material) and cut out
the next gore. Continue like this until all
gores are cut.
MAKE STEP 4
•
Lay 2 gore sections
one on top of the
other and starting
at the thin end sew
a seam 5mm from
the edge Unfold
these two pieces
and lay gore 3 on
top of gore 2 and
sew the next hem.
Continue this until
all gores are sewn
together to make a
single sheet.
MAKE STEP 5
• Turn over the
material so that
the seams are on
top and fold a 5mm
hem along the top
edge. This requires
a little persuasion
as the material
changes width.
Hem this edge.
MAKE STEP 6
•
Now with all the pieces
in-side-out lay the first
section over the last
and sew this seam to
complete the
hemisphere.The whole
thing can now be turned
right way out and the
shape should be
apparent. If you have
not used a hot cutter
the seams should be
laid flat and a second
line of stitching done
along each one. Hot
cutting is preferable as
unproofed ripstop tends
to fray on the second
stitch line.
MAKE STEP 7
• At this point the shroud
lines must be prepared.
They should be about 1.5 X
the gore length and the
same number as gores
except for the LARA
where extras are required
for the centre lines. I use
a braided polyester line of
about 20kg test on all
'chutes no mater what size
as any thing smaller tends
to get tangled very badly.
MAKE STEP 8
• Back to the sewing machine
and starting half way round
any gore on the main
circumference make a
single hem 5mm wide. Each
time you get to a seam,
double over the end of a
shroud line and tuck it
inside the hem as you sew
over it. This should fix the
shroud line in place.
Continue around the seam
until all shrouds are fitted.
MAKE STEP 9
• When you get back to
where you started fold
the seam over a
second time and lay
the shroud lines
outwards. Using a
tight multi stitch
zigzag go right round
the hem until you
return to the start
point.
MAKE STEP 10
• Gather the shroud lines
into a bundle ensuring that
the points where they
attach to the canopy are
together and cut the lines
to the same length.
Separate them into two
bundles divided uniformly
across two halves of the
canopy. Attach these two
bundles to the lead lines
from the back pack or
harness.
MAKE 11
• If you do not
intend to use a full
back pack system a
suspension point
must be fitted. The
simplest way to do
this is to sew a loop
across the top vent
hole and fit a split
ring.
Now you should have a completed
parachute.
Attach to unsuspecting soft object.
Take to high altitude and release.
THAT’S ALL FOLKS
MOST OF ALL GET OUT
THERE AND HAVE AS MUCH
FUN AS I HAVE HAD FOR SO
MANY YEARS.
www.tedberets.co.uk
If you want to see more
Please come to
WHKF Kite Festival
in May
At
A location near Swindon
www.whkf.org.uk
OTHER PRESENTATIONS
BY ARTHUR DIBBLE
1. HOW TO PARACHUTE A TEDDY
2. HOW TO MAKE A TEDDY PARACHUTE
BACK PACK.
3. HOW TO MAKE THE WHKF SLED KIT
4. AN INTRODUCTION TO KITES
(a brief outline of what kites are about)
5. KITES AND TRANSPORT
(a picture history of kite powered vehicles)