Cut out the bottom of the pie dish as evenly as you can. Make a small hole in the centre with the point of the compass.
Draw a smaller circle in the middle then using a protractor and mark out 16 22.5 degree angles. Cutting along each on to the edge of the inner circle until it looks something like this:
Angle the blades to 20 to 30 degrees. The centre of the inner tip needs to be flat and in line with the centre circle.
Tape the blunt end of the dressmakers pin blunt end down to the dowelling placing the bead on top. This should allow the turbine to spin freely.
Place a blob of play dough or soft non hardening clay into the centre of your plate. Place the dowelling in the cotton reel and press into the play dough to hold it tight. Place the four candles around the plate. Place the turbine carefully onto the pin. Get an adult to light the candles and the hot air will make it spin!
Other things to try...
Try making the dowelling shorter.
Try making another turbine with less or more blades. Which do you think will work best? Which actually works best?