here i show other one method of generate electricity . this is homemade so simple model works but if u want to build for works so u have to go with metal or use bigger one wooden plate as per want to attach piston bottom of wooden plates ..but u can modify in bigger one by using big one....
Step 1: Step 1: Buy This Type of Spring .total 16 Numbers
Step 2: Step 2: Buy Dc Generator Motor and Attach Plastic Rack ..i Got From Robotic Spare Parts Shop
Step 3: Step 3 : Understand Rack and Pinion Mechanism
Step 4: Step 4 : Buy It Battery Charging Circuit Make Connection So When Rack-pinion Mechanism Work We Can Store Energy Whenever Use .
Step 5: Step 6 : Make Circuit Connection on Plastic Box . and Finally Done
for watching details so this video :