This classical 3-hole tuner drill jig by John Gilbert makes easy work of an exacting task. The 13/32” holes are industry standard, as is the 70mm (1.378”) post hole spacing. For alignment purposes, lines are scribed center to the hole on the outside of the jig (Bushing side against the peghead). As shown in the photo at right, a steel plate can be clamped to and extend out from the head, to act as a stop. Between this plate and the jig you may need to add shim stock to center the holes. If necessary, the jig can be used as a single guide by simply moving it from hole to hole. Solidly made of cold-rolled steel and drill bushings, it measures 3 7/8” x 1 1/2 x 3/4” and is well suited for use with a hand drill.
For drilling your roller holes with this jig, use a HSSJ 13/32” twist drill bit.
Hint: The drill bit must be spinning before inserting it into the bushing.
