26/01/05
Pacman
This plan in PDF format
The Pacman kite is a totally soft kite that uses
internal lines (as used in hot air balloons and other inflatable
structures) to keep its shape. It is a relatively simple kite to make,
and should take around 3-4 days of leisurely building! The kites size
(3m diameter) has been chosen to make the most efficient use of 1.5m
wide ripstop material. In the near future I hope to make a few Pacman
ghost kites that can be flown at the same time (maybe in an arch
configuration) to bring back some retro gaming memories to the
kite-computer geeks out there (myself included!).
The kite is quite easy to construct if you have prior
knowledge of parafoil or other soft kite construction. If this is your
first soft kite you might want to read some other soft kite plans to be
sure you know what you are doing, as I have not attempted to produce an
absolute beginner’s guide. Don’t let me put you off though – what’s the
worst that can happen?? – you will have the fanciest windsock on the
kite field!!
Note: all measurements without units are in centimetres, and all figures are not drawn to scale – so don’t try to enlarge them.
To make the most of the average size of ripstop the
skins of the kite are made from five of the segments shown in Figure 1.
I sketched a template on the back of some wallpaper, and then traced
the shapes onto my ripstop. To get the curve I pinned a piece of string
of 150 cm length to the centre point and then drew the arc with my pen.
I do not mark on a seam allowance. I just try to leave between 0.5 – 1
cm when I cut out, which does not need to be accurate as it will be
inside the kite when it is finished. Five segments are required for the
front skin and five for the back skin. It will probably help later if
you mark the centre of the arc on each segment. The MOST important part
of the plan is to make sure that the angle between the two straight
lines in each segment is 60°.
Figure 1. A segment to make up the
skins. The curve is part of a circle of radius 150 cm. The angle
between the two straight lines is 60°.
Figure 2 shows the positions of the reinforcement
lines. The lines are sewn onto both skins in a grid arrangement. For
marking out I found it easiest to start with the central vertical line
and then mark each side separately. Once you have marked out the grids
sew 2 cm x 2 cm reinforcement patches (Dacron or heavy weight nylon) at
each intersection point – this is where the bridles and internal lines
will pass through. Next sew on the lines – I used 70 Kg Dyneema as I
had a roll knocking around, but you may use a lighter (and cheaper)
line.
Figure 2. Reinforcement lines positions.
Now cut out the eye and position it as shown in Figure 3.
Figure 3. The finished bottom skin with the eye attached.
The edging strip should be cut according to Figure 4.
Figure 4. The edging strip, with the mesh in the centre.
I have calculated that it should be 1085.4 x 20 cm,
however in practice I have found that the length falls short, or you
end up with some left over, due to material stretching when sewing
diagonally across the grain of the ripstop. So make sure that you leave
a little extra that can be cut off if it is not needed when you are
finally closing off the kite. In the centre at the edging strip there
should be a 100 cm x 15cm of mesh to let the air in. Once you have sewn
the mesh onto the edging strip you should sew the edging strip onto the
bottom skin. Start sewing from the middle (at the top of the kite) and
around to the centre of the kite. Then sew the other side. Now sew the
back skin to the edging strip in the same way, so that the seam will be
on the inside of the kite, (see other parafoil plans if you don't
understand), leaving enough open to allow you tie in the internal lines
and bridle lines.
Now sew and tie in the internal lines to the lengths shown in Figure 5.
Figure 5. The internal line lengths for one half of the kite (the other half is a mirror image).
The lines should be sewn so that they pass through the
reinforcement material and out the kite, pass diagonally over the
reinforcement lines and back through the skin and tie your favourite
knot!
Tie your bridle lines to the kite in the same way as
the internal lines, except on the outside of the kite. The bridle
consists of primary and secondary lines. Figure 6 shows the primary
bridle lengths.
Figure 6. The primary bridle lengths.
The bridles of the same colour shold come together and join onto the
corresponding secondary bridle (see Figure 7).
The primary bridle lines are grouped together in rows
indicated by the colours of the line lengths in Figure 6. The secondary
bridle lines, shown in Figure 7, should be connected to the primary
groups of the same colour (again, see other parafoil plans if you don't
understand).
Figure 7. The secondary bridle lengths.
For primary bridle lines you only need a breaking
strength of about 50 lb, and for the secondary about 200 lb. Sew a
small loop of line through each of the outer rear bridle points (marked
with the bridle length 328 in Figure 6). When you fly the kite these
loops are where you will attach your drogues. The drogues should be
attached in a Y configuration. Each part of the Y attached to the kite
should be about 4m long.
After all the lines are attached you can close the
kite. You will have to roll it inside-out to keep the seam inside the
kite. Sew the open part of the last seam, but leave a small gap to
allow you to turn the kite the correct side out - then close the kite
as neatly as possible.
Ensure the kite is fully inflated before allowing it
to take off. If you don't then the front will collapse as the kite
rises to its apex. I have tested the kite with a 15m tube (20 cm
diameter) attached like a skipping rope - this produced enough drag to
stabilise the kite. I will create a series of drogues in the near
future to replace the tube tail - I'll add these to my plans page when
they are done!
Please send me a photo of your kite if you decide to
make one. I will post it on the website. If you modify the plan I'll
also be interested to hear what you have done and how successful it is.
I have already know there is someone who is interested in turning the
kite into a smiley face - maybe someone could make a whole range of web
forum 'similes'!!
Finally - good luck!!
If you want to email me use the following address, with kites as the subject – messages with other subjects will be sent to my junk mail folder and will not be read!!
You can also catch me at the Kite Builder Forums ( http://kitebuilder.com/forums/ ) with the user name ‘TS’.