Â Â Â When you need to do a lot of pushing and pulling use a motor and a screw.Â The tricky part is attaching the screw to the motor so that it doesn’t wobble too much but sometimes that can be a good thing. Here we have a butterfly made of red craft foam sheet suspended three wires. A wire attached to each wing and one in the middle. The middle wire is connected to a nut on the screw that goes up and down as the motor turns forward and backward.
Click the picture below to see it work. Just imagine a whole flock of these.