I have received a number of requests for ukuleles with a radiused fingerboard (a slight convex curvature of the fingerboard). This is supposed to make playing easier, particularly if you play bar chords, with a finger (naturally curved) across all four strings. A 12 inch radius of curvature seems to be pretty well accepted. The issue is, how to easily and reliable cut the top surface of the fingerboard into the proper radius. I have seen a number of jigs around, but a number of them were rather complex to construct. I came up with the following design.
Using the laser cutter I cut 12″ radius curves into two matching acrylic side plates. (The laser cutter allows one to make things very exactly, exactly a 12″ radius, and the two side plates are exactly the same.) I realized that one only needs to have 2 points for these curved side plates to slide along to get a circle, so I used two sections of 3/4″ PVC pipe as it is very uniform, and rather slippery. I routed two parallel groves into a pieces of really good plywood I came up with and bedded the PVC in auto bondo. I epoxied the side plates to a top piece of good plywood, and added a threaded insert to the top with a corresponding hole in the acrylic baseplate of my router so I can easily affix the router to cut fingerboards, and away you go. Works great, so in the future a radiused fingerboard will appear on some ukuleles, and will be an option for a custom order uke.
