serious water rocketeer develops a sensitive feeling for PET bottles
over time - too often he finds himself scanning his surroundings
for empty PET bottles apt for rocket or other use.
Once in a while I hear from new original uses of PET material, which
are presented here.
Here is another creation of Andrew Kinsman (Sneelocke@aol.com):
from wooden sticks, foam, and four 2-liter PET bottles,
glued together just like bottle rockets. This one weighs
in at 5oz.
Assembly: connect four bottles
after sanding the contact points, glue them with gorilla
glue. Insert several foam ovals, smallest dimension
is 2.5 inches. This assembles a tubular oval. Insert
a nail in the sticks and use safety pins, or fish
line swivels on the nails to form the necessary bearings
so the kite can spin. Connect two lines, one to each
bearing. For very high winds replace the wooden sticks
with carbon fiber arrow shafts. Insert short wooden
plugs to push the nails into. Whip the ends of the wooden
sticks with thread and apply super glue to keep the
nails from splitting out due to the side forces. Fishing
line swivels work best as lines don't twist up. Use
1/2 inch thick foam if you can find it, 1/4 inch for
inner ovals. Use 1 inch foam and split them into 2-3
ovals with a sharp non-serrated meat carving knife.
Less glue is better to keep the kite lighter. The two
foam circular disks on the ends add gyroscopic stability
and protect against damage. Make them only slightly
larger than the wing.
Launch the kite
by spinning the top of the horizontal kite away from
the pilot. This kite is extremely maneuverable and is
best used over water to save on repairs. It likes wind
in the 10-15 MPH range, and has flown in wind over
40 MPH. Landing is difficult, best dunked in water,
or have a friend put one arm over each string and walk
towards the kite and catch it. If someone helps you
launch it, never let them spin the top towards the flyer!!!
This causes great lift towards the ground, and sure
destruction." (November 2005)
you, Andrew, for this very creative idea. Flight reports
More on rotary kites on Andrews
Homepage. Or here.
David G. Leatham from Anacortes, USA, found this
nice-looking windmill from soda pop bottles in Renton,
WA. Instead of guy wires, the bottles on the plastic
pipe keep the support from bending. (May
Doll's Washing Machine
Last christmas my 8 year old nephew Joel asked me
to help him build a Doll's Washing Machine for his sister
Eva. I promise that I have not influenced him to use
a PET bottle - he all by himself wanted to use a Volvic
water bottle. We cut away the bottom of one bottle,
shrank it a little to make it fit into another bottle
top. A cardboard box was used as bearings, and
we even used a cordless drilldriver as a 2 directional
here to see it move)! It was a big success on her
birthday: "Eva laughed herself silly!"
Chain Reaction (Kettenreaktion)
by Tobias Horriar. This is the most elaborate construction
using PET bottles that I have seen so far. It is an
apparatus using not less than 137 different effects
on an area of 1 m2, one firing the next.
Here are just the first 13, translated form the original
with igniting a sparkler ; a
PET bottle (!) catches any hot sparks. The sparkler sets fire to a thread 
and the attached lever  falls down. The thread was
soaked with ammonium aluminum sulfate, NH4Al(SO4)2
to prevent catching fire. The lever presses a switch
 by its weight, so that a high current from a thick
battery  runs through a very thin copper wire .
This wire gets melted. Thus a further lever 
falls down and with it a tube , which rests on a
photoresistor. Now the light of the two bulbs  may
fall on the photo-sensitive area and the photoresistor's
resistance drops. Therefore an electric motor 
starts running and pulls another lever  upward,
whereupon a wire is fastened; now a piece of aluminum
foil  is affected. Wire and foil form a short-circuit
with a strong transformer and thereby a hole is burnt into
the foil. By this hole water from a PET bottle (!) 
flows into the glass below. A lever is held up by
stacked sugar cubes, which lowers itself as soon as
the sugar cubes are dissolved. This goes on until
effect #  here
(in German, click "Kettenreaktion". Use
to translate the entire site).
by Andrew Kinsman (Sneelocke@aol.com):
"It is made
from forty 3-liter bottles with each tube pressurized to 5 PSI to add
rigidity. It weighs only 14 lbs and is really easy to car-top at 12 feet
Thanks, Andrew, great idea! Looks like fun.
More on Gondola
construction on Andrews
Why not pressurize to 80 psi and release the air under
water for a good but short forward thrust? (kidding)
Putt Putt Boats (Knatterboote)
On Freiburg's Model Fair in May 2004 a school organized
a competition. Every participant had to build a Knatterboot.
Luka Fischer (left) made one from a PET bottle, cut
in halves, nicely painted in red and gold. The right
pic shows the copper tube coil, heated by a white
tea-candle underneath, protected from wind with the
aluminum shield. Both ends of the copper tube
end astern in the water. The tube is filled before
start with water, the candle brings it to a boil. The
first steam bubble drives water out of the ends, giving
the boat forward thrust. It develops a pulsating water
stream out of the exhausts, with a "putt-putt" or
(German: knattern). The fastest boat won, of course,
but I didn't stay long enough to see the race of all
of the 60+ boats). Click
here for an article how to build one.
Three more Knatterboote
Left: a PET bottle used as bow (boat front).
made from a herring can
Right: hull made from foams
in national colours. Sail says "environment".
Model hovercraft from an old CD
This idea was discussed by Tom Benedict and David
Leatham in the WR list. I built it with kids -
here you see the final product, being blown way across
You may ask "Where is PET
used here" ? Click here for the
answer and more pics on construction.
1 1 insects fly in here
1 v v 1
1 v v 1
1 v v 1
1 v v 1
1 1 "b's" trapped in the bottle
1 b b 1 can't find exit
1 b 1
1xxxxxxxxxx1 bait in bottom
1xxxxxxxxbx1 (+ drowned "b")
Wasp & Fruit Fly Trap
Rob Vida wrote in October 2003:
"We have a bit of a problem here with wasps
that like to spoil barbq's and picnics by buzzing around
the food and people in a threatening way. Very painful
stingers back up the throats. Canned pop is a dangerous
thing as they hide inside to get the pop and then sting
your mouth. ANYWAY, we make traps from 2L bottles with
a bit of pop in it and it works great. Just cut the
top third of the bottle off, turn it over and put it
back in the open end of the base (v).
Seal it in place (tape, glue, etc.) put in some pop
or even better things like smelly old juice, skunky
beer or whatever smells strong but suggary (xxx)."
Thanks, Rob, for this tip. We've got annoying wasps
over here, too. They'll soon learn about this ....
David Leatham added: "This same trap is great for fruit flies
- use vinegar as bait.
My neighbors have
5 Apple trees and the only pickers are the wasps...U can
'breathe' fruit flys here!". Thanks, dl.
Catapult for humans
This is no "other use" of a PET bottle,
but a nice and exciting "other use" of
our Water Rocket propulsion technique. The courageous
lady on the picture is being thrown into the swimming pool
ca. 3 G
down to 1/min
water exhaust speed:
required pool depth:
from David G. Leatham (Dec 2002). He
"'Coke About' is a 3L Rocket Car. My 1st try. Finding
that CD's fit on the bottle tops so well gave me the idea. I've always
wanted to try a car and felt the wheels should almost be fins. These wheels
will easily break but can be replaced very quickly. The funnel on
the front is to test another idea - push air thru a little green toy siren that is
pushed in the nose. Also there is a scoop up top to exhaust the air from the siren. Could
not resist using up those toy eyes I'd been saving.
It uses PET in several
unique ways: the rear assembly swivels for a slight
suspension action, and there are spring washers to steady
lady in the rural Allgäu region (pretty close to the famous
castle Neuschwanstein) showed me her way of keeping
the snails away from her salad in the garden. She tried
many other tricks, nothing worked. And now:
installation is perfect!"
HMS Coca Cola light
On the Freiburg model fair in June
I saw this nice ship from an experienced modeler who
was tired of building "regular" ships. So
he started searching for more original designs like
this ship "Coca Cola light".
this photo, he opened up the cover. In black on the
right the servo for the rudder, in brass, left
of it, the drive motor.
From the same artist: although it is not made of
PET, I include this interesting submarine ship U4711,
made from a canteen (military WW II water bottle). The
periscope is used as the antenna.
4711 is a famous old fashioned perfume in Germany.
From the same artist: although it is not made of
PET, I include this interesting "Nessie" type
submarine from an old copper hot water bottle.
Both these submarine creations do really swim and
Bicycle fender extension
This is a creation of my own. Modern bike manufacturers save
material even on the fenders. Mine was too short; when
driving in the rain, road dirt kept splattering on my
stuff on the rack. So, in May 2000, I lengthened the fender a bit
with this crumpled piece of PET and 2 office clips. No dirt
on top of my rack any more. This fender extension is very
light and indestructible!
A REAL QUICK-AND-DIRTY SOLUTION!!
Dessert dish (and more)
This nice dessert dish comes from Japan over Thailand to us.
Many more interesting PET ideas like a plant pot, aquarium,
raft, wind catcher (Windrad), even a kajak on Pitan
Maybe someone sends us a picture on
Intellectual activation toy for dogs
(yes - dogs do need to use their brain cells!)
Calvert from the WR mailing list sent me this nice application:
Use a large PET-bottle of thicker quality, not the
thin, flimsy ones. The bottle should be big enough so
your dog can't grab it with its teeth. Cut the bottle
just below the screw fitting (otherwise the dog will
be able to chew it up...) and sand the edges so they
wont cut your dog.
Put some treats in the bottle;
sausages or meat balls cut in pieces, dog food pellets
of appropriate size. Then watch your dog try to get
the treats out of the bottle.
It's great fun to watch,
and after some false starts your dog will get the hang
of it and, with time, become quite expert! To make it
easier in the beginning, cut the pieces small enough
so that all three dimensions (length, width and height)
are smaller than the diameter of the opening.
dog has learnt to roll the bottle into a corner and
then set it spinning with her paws. When it hits the
walls it's jackpot-time!
Brad has a list of "Other PET uses",
well worth to view. It is on http://www.netspace.net.au/~bradcalv/petbot.htm
and includes amongst many others: Rain gauge, Terrarium,
Submarine, Timber protector, Hourglass, Mini-greenhouse,
Flying insect traps (the best).
Did you see any other funny non-rocket use of PET,
our main water rocket material?
do not hesitate to send me a digital picture and some
words of explanation. I am happy to publish it here.