is a fun litle animation that is easy to do.
I started out by making a tombstone in my normal fasion.
I made this stone from 2" thick insulation foam. Then I made a wooden frame for the base to hold the motor and support the stone.
is a diagram of the setup. I used a small motor I had from a store display.
This is about a 12 rpm motor but I replaced the 4 D cells it ran on with a 3vlt
This slowed it down to about 5rmp (guessing). The motor already had an off set cam,
but one could easily be made. On one corner I made a pivot point using 2 pieces of wood I drilled a hole to accept a 1/2"piece of pvc for the pin. I mounted the motor at the other end and attached the arm from the cam to the bottom of the stone. When the motor is turned on the stone rocks back a forth!
Above is pic of the actual motor setup. It's a little messy because I changed things around a few times when building this project. Research & Development.