1. Grab Qt. Project Info on front cart.
Welcome Back!
Grab Qt. Project Info on front cart.
Prelim Date: April 22
Final Date: May 12

2. An Introduction to Water Rocketry
Mrs. Hlinka
UMS Science

3. Important Rules Must use a standard 2 liter soda bottle
No glues, metal or wood allowed
Measured on time in the air
Time stops when the first piece of your rocket hits the ground

4. Parts of a Basic Water Rocket

5. Parts of Rocket (cont.) Nose Cone- For aerodynamic effect
Ballast (not always necessary) but adds mass to rocket for increased stability.
Fins- for stability
Pressure vessel- source of rocket propulsion. ** Must be airtight!

6. When preparing your 2-liter bottle do not use the following items:
Hot/Boiling water Knives/Razors
Sandpaper Chemical Adhesives
*These things may compromise the structural integrity of the bottle.
Remember it is pressurized with air!

7. What Do I Need?
One 2-Liter bottle (or more bottles if you want to make a tall rocket)
Materials for Fins
Materials for Nose Cone
Materials for Parachute
Tape

8. The Rocket Body One bottle is all that is needed for a basic rocket.
If you want to make a taller rocket cut the bottom portion off another two liter bottle.

9. Rocket Body: Ballast
If you want to add some ballast to your rocket you can use items such as: sand, foam peanuts, modeling clay, newspaper, etc.

10. Rocket Body (cont.)
Push bottom half of two liter bottle upside down into top half – to keep ballast in place.
Use small pieces of tape to secure bottom piece inside bottle.

11. Rocket Body (cont.)
Place two liter bottle (pressure vessel) into top half. Try to make bottles straight. Use little pieces of tape to secure bottles. This is not necessary if you are using a single bottle.

12. How Do I Attach Fins & Nose Cone?
The packing tape with strings is my favorite. It holds really well and makes it easier to repair your rocket quickly!
Duct tape is also excellent!!

13. Fins are the guidance system for your rocket.
Square/Trapezoidal:
Fins yield MORE stability, but create MORE drag.
Triangular/ Epsilon:
Fins introduce LESS drag, but yield LESS stability.

14. Materials for Fins Milk or Juice bottle Foam trays
Unused election signs (work great & are water proof)
Cardboard
Corrugated Plastic
Plastic Folders
Poster board

15. Fin Templates (or design your own!)

16. Fins
Use a template, a marker and draw fin patterns on the material you have chosen to use.

17. Fins (cont.)
Cut fins out.

18. Measure for Fins
Measure your rocket to make sure the fins are equally placed around bottle.

19. Fins (cont.) Attach fins to rocket using tape. Use either 3 or 4 fins.
More than four adds unnecessary weight.

20. Materials for Nose Cone
You can use many materials to make a nose cone.
To create a rounded tip you can use an egg carton or a plastic egg shell.
Small Nerf footballs, foam noodles, foam balls, etc. all work well & allow the rocket to make a soft landing!

21. Nose Cone Materials

22. Nose Cone
Roll your material (plastic file folders work great) into a cone.
Use tape to hold material in place.
Place plastic egg shell on the cone as tip. Use tape to fasten tip to cone.

23. Nose Cone (cont.)
Fasten nose cone to the body with tape.

24. FLOUNDER NOSE CONE
The first type illustrated here is called "The Flounder".
It is the easiest to make but lacks flight stability. The
cone is made from poster board or tag board. You
can make the cone by simply cutting a large circle out
of the poster board (about a 6 inch radius). Cut a line
from the outer edge of the circle to the center on the
radius. Overlap the cut edges and turn the circle while
holding one edge stationary until you get the desired
cone shape. Secure the cone with staples or tape.
Attach to the bottle with tape or similar adhesive.

25. As I mentioned before "The Flounder" lacks flight stability,
this can be fixed to a degree by pressing a small lump
( a few ounces) of clay to the inside of the nose cone.
This will add mass to the cone and keep your rocket
from flipping end over end while in flight. This new
and improved rocket could be called "The Bullet".
You can also put a golf ball or tennis ball in the nose cone
for top weight.

26. “Bertha” Nose Cone The "Bertha Series" nose cones are easy to make
as well but require a little attention to detail. The
"Bertha" nose cones are made by cutting the bottom
off a spare bottle and attaching the top portion
onto the pressure chamber. One strip of tape should
be enough to hold the cone on. (Note: Never
cut the pressure chamber) Using this method
you can even make your "Bertha" rocket two or
three nose cones tall! (we call that a "Big Bertha")
Within the top nose cone you can add a small lump
of clay to increase the mass. Pay attention to keep
all the cones in a straight line. A curvy rocket will
not be safe coming off the launcher.

27. “Space Needle” Nose Cone
The "Space Needle" style of nose cone can be made
from a spare bottle, empty paper towel roll, and
a tennis ball or racket ball. This type of nose cone
adds a great deal of inertial mass to the rocket and
makes it really stable. Simply, attach the towel roll
to the top of a single Bertha nose cone and then fix
the tennis ball to the top of the roll. Take your time
building this set up because you want the entire
assembly to be straight as an arrow.
Cut tabs in an index card and glue or tape
the card to the tube. This will hold the tube
upright. Then glue or tape the tabs onto the
nose cone top.

28. Recovery Systems
A recovery system is something that slows the rockets decent.
The two most popular at the parachute and the back-slider

29. Parachute
Parachutes work best but are harder to get to work consistently
The size needs to match the rocket.
It should have 8 to 10 strings
Fold it like an accordion and then wrap extra string around it to keep it folded

30. Making a Parachute
Cut Here

31. Making a Parachute

32. Backslider/no parachute
Backslider is made by making the center of gravity close to the center of pressure
This prevents the rocket from turning over at apogee and instead floating down on its side.
Fins on this type of rocket should be larger to help slow it down.
Acceleration down = (m*g – v*b)/m

33. Example Backslider

34. Decorating Your Rocket
You may decorate with stickers, paint, wrapping paper, etc.
The bottom of your rocket though must remain clear of any obstructions.
Fins cannot extend past bottom half so that the rocket will fit on the launcher.

35. How Do I Launch My Rocket?

36. Launch Pad

37. BE AS CREATIVE AS YOU WANT !!
Tips
Lengthening the rocket adds stability
Experiment with different fin shapes
Try different body shapes
Try to make the body smooth (no kinks with tape).
Do not use any glues, masking or scotch tape, wood or metal on your rocket.
BE AS CREATIVE AS YOU WANT !!
HAVE FUN!!