Doable Renewables: 16 Alternative Energy Projects for Young Scientists
IIIO The needle should be 15 inches long If your needle is a differ ent length adjust the width of the base The base should be 14 inch shorter than the length of the needle The rubber bands I used are 7 inches long cut apart and measured without stretch ing and 1 16 inch wide You can experiment with this but a band that is too strong or short may bend the needle But if the band is too loose it may not contract properly when heated Glue the three base pieces together in a stack The complete base assembly should appear as shown
Glue the side pieces together in two pairs Each pair should have one piece with a hole and one piece without a hole Flip one of the assemblies around so that one hole is on the left side while the other assembly has the hole on the right side H The completed side assemblies should appear as shown here Glue one side assembly to the base assembly as shown Note that the hole faces up toward the base
After the glue is dry from the previous step glue the other side assembly to the base with the holes facing each other Now use the rubber bands to suspend the needle in the center of the rotor One at a time wrap the four rubber bands around the rotor and loop them over the needle as follows place one end of a rubber band over an end of the needle bring the rubber band around the rotor and loop the other end of the rubber band over the opposite end of the needle Repeat this with the remaining three rubber forming X as shown bands an here
Once the rubber bands are in place the needle should be in the center of the rotor Adjust the rubber bands to make them even by sliding them along the outside edge of the rotor The tension on the rubber bands must be adjusted so that the needle is per pendicular to the rotor Notice how the upper part of the needle is slanted incorrectly toward the left in this photo To correct this pull the thumb on the lower part of a rubber band to the left while pushing the finger on the upper portion of the rubber band to the right The goal is to get the needle the axle on the motor perpendicular to the rotor as shown
