While doing some flooring a while back we came across the need for a contour gauge. Truthfully, that was our first exposure to ’em. They’re a bit puzzling to figure out at first glance. They look like a rather bad metal comb, but actually they’re hot stuff for replicating an edge or contour.
The concept works by lining up the steel pins along the contour or shape then pressing them into the contour enough to make a negative of that shape. The other side of the pins are connected to the negative side and form the positive end which you can trace or check against another piece of wood or metal. We’ve also seen them employed to shape soft clay and Styrofoam in model making.
Contour gauges come in different sizes and pin depths ranging from 3” wide to 1’ and pin depths from 1” to 6” depending on what task it’s made to handle.
The $3 at Harbor Freight will be well worth it the next time you need to make an exact copy of a complex 3D curve. If you’re looking for more of a “name brand,” we found one for $7 on Amazon. Personally, we have the cheap-ass version.