A rubber band runner made of a copper wire spool, a wood stick and strong rubber bands

A bottle runner sample

Materials: Two same shape plastic bottles, a bamboo skewer, two plastic washers, a bottle cap with a hole, rubber bands, a hard plastic straw

Tools: A hot nail (a pair of pliers, a portable gas burner and a 6 mm in diameter nail), a cutter, a compass shape cutter, a pair of scissors, a sharp object, two 60 cm copper wires, a one-hole punch,

The above photo shows the size of the plastic washers and the hole of the bottle cap.  You can use a compass shape cutter to remove the washer part from a carbonated drink plastic bottle.  Then use a one-hole punch to make a hole in the washer.

Please make a hole exactly in the middle of the bottle cap using hot nail.  Make sure the hot nail is very dangerous.  Be very careful not to be burned.

We can use various bottles to make the bottle runner.  Left photo shows a plastic bottle sample.

It has 9 bulges.  From 1st to 4th bulges have small diameters and from 5th to 9th bulges have slightly bigger diameters.

Give the first cut on 5th bulge using a cutter and using a pair of scissors, remove lower part of the bottle through cutting along the 5th bulge.

Trim off nicely along lower end of the 4th bulge.

Observe the upper half of the bottle carefully, you can find two vertical lines.  From the lower end of the upper half of the bottle give two vertical cuts along the two lines up to above the 3rd bulge (each cut pass through two grooves).

Make a small hole using a sharp object on one of the upper half of the bottle like the photo above.

The hole should be below the screw and on the line.

Make another hole exactly on opposite side of the bottle (on another line).

Pass a bamboo skewer through the two holes.  Then trim off the skewer.  The skewer passing the bottle must be shorter than the bottle diameter.  The skewer will work as a rubber band stopper.

Insert the lower end of one of the upper bottle halves into another upper bottle half’s lower end.

Make sure the grooves between 3rd and 4th bulges are nicely overlapped.  The connected two upper halves is called bottle runner body.

Connect 6 rubber bands to make a rubber band chain.  (Number of the rubber bands depends on the quality of them.)  Pass two 60 cm copper wires through end rubber bands of the chain.

Insert copper wires in the bottle top, which has the rubber band stopper.  Ends of the first copper wire must pass above the stopper and ends of the second copper wire must pass below the stopper.

Make the copper wires totally pass the bottle runner body.

Pass a bottle cap with a hole and two plastic washers through the copper wires.

Screw the cap to the body and pull the copper wires to take the rubber band chain ends out.

Pass a hard plastic straw though rubber band chain ends.  The plastic straw works as a winding handle.

Hold the body with your left hand and using your right index finger, wind up the rubber band chain through rotating the winding handle clockwise or anticlockwise.

Then place the bottle runner on the floor and release it.

If you place the bottle runner on the floor like the upper left photo, it tends to go rightward due to the friction between the plastic straw end and the floor.

If you wind up the rubber band too much, the bottle runner body might skid on the floor.

In order to make the bottle runner run straight, we can make outer diameter of the body at winding handle side slightly bigger than the stopper side.

Apply two thick rubber bands to near bottle shoulder of the winding handle side and apply a rubber band to the opposite side.

These rubber bands give the bottle runner and the floor bigger friction to avoid skidding.

You can change the number of the rubber bands to apply on the body and find out the suitable number of the rubber bands to make the runner run straight.