FABRICATION AND WORKING OF PUTT PUTT

BOAT

Presented byVAMSHIDHAR

INTRODUCTIONOften toys can be found that

employ simple physics principles in ingenious ways and one such toy is putt putt boat

The boat was invented and patented by a Frenchman named Thomas Piot in1891

A putt-putt boat is a toy with a very simple heat engine without moving parts, powered by a candle or oil burner. The name comes from the noise the boats make

WORKING PRINCIPLE

Heat from a small candle inside the boat makes it eject pulses of water from tubes at the rear just under the water level, at five or more cm per second. That propels the boat at 10 cm/s or more, and it will go for as long as the candle burns.

FABRICATION

Materials Requireda. two 2-litre (1/2 gallon) milk

cartons with ends cut offb. two flexible drinking strawsc. one (used) birthday candle,

only 1 1/2 cm longd. large paper clipe. soft drink can, the thin,

aluminum, 355 ml typef. aluminum foil (only about 20

cm off the roll)g. metal tape, 5 cm wide; a

piece only about 10 cm long, cut lengthways into 3 equal strips

Tools Requiredsharp scissorsglue stickTapea few clips to hold parts

while glue driesSandpapersharp one-sided razor bladeruler a pair of pliers to bend the

straightened large paper clipcaulking gun with waterproof

caulkinga fine-point felt pen would

be handy

PATTERNS

Details about these nine parts:

A support for the "tail-pipes" and it measures 5.5 cm x 1.5 cm

B the cabin; overall length is 12.5 cm; the middle part is 2.5 cm wide.

C the transom support; it folds in the middle and is glued over the actual transom to give it more

strength; 6.5 cm x 8.2 cm.

D pattern for cutting the soft-drink can which becomes the "steam chamber"; 10 cm long; the middle part is 2.5 cm wide and the two edges are .8

cm wide E brace to keep the sides of the boat a proper

distance apart; 7 cm long; each part is .7 cm wide

F - This part is cut from the DOUBLE edge of the milk carton so it is 2x as thick as all the other pieces; it is for the rudder, it measures about .5 cm x .5 cm and has a pin-hole in the middle

G - roof of the cabin; two cuts are for holding the chimney; overall it is 10 cm x 8.6 cm

H - the chimney; the one tab on the end slides into the cut in the other end

I - rudder; folds in the middle

Final layout of the boat

"K" is the deck of the boatPart L is is a tool to help place the cabin(part "B") precisely on the deck.

Construction Print out the 3 sheets of patterns Cut very roughly to separate all the pieces Take the boat hull or body and fold where

needed Use sandpaper to roughen the inside of the

gunwale so that the glue stick will work better and glue them

When the glue from steps 3 and 4 has completely set/dried, carry on with the bow (front)

Now fold part C, the transom support, on the line and fit it into the boat, over the transom, to make SURE that it will fit perfectly

Part H, the chimney: pull this part over the edge of your kitchen counter a time or two, printed side under, to make it nice and round

Now take part G, the cabin roof, make sure the two curved slots are cut, and then slide the two tabs of the chimney into those slots, on the TOP side. Put a dab of J-B Weld on the tabs on the underside of the roof.

Now take part L; and glue it onto the deck where you want the cabin to sit

Take the roll of aluminum foil (approximately 30.5 cm wide) and cut off a piece 10 to 15 cm wide. Roll this foil, from one end to the other, around a drinking straw or a pen

First, take the clean soft-drink can and cut off the ends

Tape pattern D, the pattern for the steam chamber, onto the aluminum and cut out one piece.

Now make 4 tiny tape pieces and stick them on the underside of the steam chamber, that is, the side which does not have the folded edges

Now take the two flexible drinking straws. Push both of the long ends into the steam chamber as far as they will go.

Take the large paper clip and make it as straight as you can

Glue the rudder onto the back of the boat, centered as well as possible. I like to set the boat into a mug, nose down, rudder up, until the J-B is dry.

Lastly, attach the deck and rear trim

MECHANISMS TAKING PLACE

Priming• Two pipes run from the heated

chamber (boiler) to exit at the back of the boat. Why two?

• The system must be primed before the heat is applied, by putting water into an exit tube. It will go in only if air can come out.

• That the second pipe serves no other purpose was shown by plugging it after the system was primed and running. The pulsing went on

GravityAs the boat sits in the water, the two

pipes have a downward slant Boer turning up to the boiler.

While the motor was running, the boat is topped upto 45 degrees, keeping the exits of the pipes under water.

Put-putting continued. This showed that, whatever the water does, pressure changes in the boiler must be more important in moving it than gravity is.

Temperature of the pipes• After running a minute the heater

tray was removed quickly and the pipes were felt with a finger.

• They were cool up to where they started to bend upward, then too hot for the finger.

• That showed that live steam may get into the bend but not further.

CONCLUSION