Building a seesaw with sliding seats
Wood & wood size explanations
The measurements throughout this project are given in both standard (inches) and metric (millimetres).
The standard measurements (inches) are given first followed by their metric equivalents in brackets.
Use a treated dressed (surfaced, dimensional) wood. Dressed wood
will actually be less than the sizes (width, thickness) given in this documentation.
Make any necessary allowances - easy peasy.
How strong to be!
My grandkids tend to be a bit rough-and-tumble when it comes to using the play structures I make for them.
To compensate, I pretty much tie everything together with galvanized metal strap or similar fastenings to ensure minimal give or pull. I like to make sure the things I make are going to be around for a while and are able to take any punishment likely to be dished out to them.
Such fastenings are optional for this project. Good glue and screws alone should suffice in a gentle world, but,... by using the extra fastenings, for little extra cost you can have a much stronger unit. it's entirely up to you.
Make and use at your own risk.
Many a mishap has occurred on a seesaw so all due care should be taken.
Kids should be supervised by a responsible person (assuming you can find one).
A tire under each end of the seesaw can take away a bit of the jar when one kid jumps off quickly without warning (usually on purpose) while the other's up in the air.
Baring all that, there's a lot of fun to be had.