Many complex shop tasks can be simplified with basic geometry. One good example is laying out an Octagon on the end of a square board. The math required to calculate the distance from the corner to the next point on the Octagon is more than I care to pursue. Luckily, through the magic of geometry we can easily mark of this distance with a compass.
The only tricky part is getting the point of your compass to register into the corner of the board (This is especially tricky with dimensional lumber, where the edges have round-overs).
For perfect results, the point needs to bite into half wood and half air.
My solution is what I’m calling the Corner Center.
This little gizmo perfectly aligns the tip of your compass with true corner. The magnet in the body also holds your compass point securely, ensuring accurate results.
Here is the tool ready to assemble. As you can see, it comes in three parts. The body, the cup and the magnet. A dab of super glue ties it all together.
First find the center of the board and set your compass to the distance from the center to the corner.
With the compass set, just position the Corner Center at each corner and make a mark on each adjacent edge.
After you’ve made marks from all four corners, just connect the marks for a perfect Octagon.
Check out my page on Shapeways for this tool and more good stuff.
Corner Center Body – Link
Corner Center Cup - Link
Wisp Woods Shapeways Shop – Link
-- - You begin thinking less, and feeling more.