what is he doing?

[btberlin]

I have been looking at this link, which has a photo of a compass being used to trace a curve on a saddle. Bt, from the picture and text i cannot figure out what the hand is doing! Can someone help?

[url]Link: http://harvestmoonguitars.com/kennethmi ... addle.html[/url]

[Cbstark46143]

I used tools like this as a trim carpenter. With the compass held so that the point and the pencil are kept “vertical”, the hand moves left to right to copy the curve of the bridge onto the saddle. Apparently the radius of the bridge already matches the radius of the fretboard.

[ruby@magpage.com]

Interesting - he is copying the curve of the top of the bridge, NOT the curve of the fretboard. My daughter has her own repair shop and she has a set of fretboard curve measuring gauges:

https://www.stewmac.com/Luthier_Tools/T ... auges.html

She measures the radius if the fretboard, then picks the next tighter curve and traces it on the saddle then trims it on the belt sander