The method I've used for years works extremely accurately. Of course now I have most radii made, what I did was use a method that was shared with me some time back.
Measure out on a piece of 1/2" MDF the lenght of the desired radius. Using the circle maker on your router, set it up for the desired matching radius ( we'll say 14" now for simplicity) . Cut out a 14" radius 1/2
circle. Now you have a perfectly matched radius. Construct a universal base where you can press the different radii boards you made with your router in. make sure each radii boards fit snug in the base.
Cut a slot down the middle of each radii just big enough to accommodate the fret wire. I used a table saw blade from a hobby shop . Now you can press( or use your dead blow hammer to tap the fret into the slot
until it seats. make sure your fret wire has a little over lap so you can smoothly remove the wire once shaped. Wahhlaa..a perfectly shaped piece of fret wire. I found that making each bending jig to big tends to get
sloppy so keep each jig small enough to fit approx 2' lengths.
happy fretting !!
