Dasco Pro 1405 Giant-Circle Beam Compass
Woodworkers have plenty of ways to mark out circles. Little circles -- up to perhaps 3” diameter -- are easy to cut with a hole saw. Anything bigger means that bringing out a different sort of tool like a jig saw or a band saw, depending on the use. Assuming you have a saw and the stock to cut, the problem becomes one of "How do I mark a curve that large???" You could root ask your kids for their compass (what the geometry teacher calls "dividers"), but they’re good for a radius of about six inches at most. What if you need to mark a curve with a twenty- or thirty-inch radius? Or larger? Do you struggle with string, a nail, and a pencil?
Nope: you pull out your Dasco Pro 1405 Giant-Circle Beam Compass and a half-inch dowel, and quick as a whistle you've marked a curve. It actually is that easy.