SeeSaw query

Here is an example with physics:

dropbox.com/s/40iv4ratrqcxsgd/Seesaw.c3p

Thanks dop2000 .We are closed to crack the logic .But we are curious to know what does that sprite significance in the project because if we move the sprite from the layout , we still see the see saw working smoothly. But if it act as revolute point why doesn't it comes to the below of see saw platform?

Yes, that round sprite is a revolute point, like a nail.