There’s a fast and straightforward technique to discover the middle of a board — and also you don’t want your tape measure or to work difficult math issues.
Simply make a self-centering jig!
To do that, drill three holes into a brief size of 1-by-2. On every finish of the 1-by-2, drill a 3/8-inch-diameter gap, after which drill a 5/16-inch-diameter gap within the center.
Then take 2-inch-long, 3/8-inch-diameter picket dowels and hammer them into the surface holes. These are the pins.
While you use the middle finder, merely sit it on a board and rotate it till the pins make contact with the sides.
Then, put your pencil within the center gap and slide it alongside. You’ll have a line proper down the precise middle of the board!
It doesn’t matter what dimension the board is, so long as the jig is lengthy sufficient, and the jig’s middle gap is strictly centered between the 2 pins.
Watch the video above for Joe Truini’s middle finder in motion!