Drill Jig - Steam Holes at 15th Fret (Neck Reset)
Jun 22, 2020 13:53:02 GMT -5
Derick, RobertW, and 2 more like this
Post by CTGull on Jun 22, 2020 13:53:02 GMT -5
To remove the neck to do a neck reset you need to inject steam into the neck pocket to loosen the glue. The neck pocket is under the fretboard, about 1/8" to the left of the 15th fret (towards the 14th fret). To inject steam you need to drill 2 holes. I normally use my scale and pencil to lay out the position, then carefully drill the 3/32" diameter holes starting vertical (less chipping), then angle it about 10 degrees to the right. The drill tends to walk up the fret slot, and pushing too hard at the start can cause a nasty chip. A chipped hole needs to be repaired, typically filling the hole with rosewood dust and superglue (with a plastic spacer in the fret slot), the scraping and sanding it flush. This can't always be done, especially with a vintage guitar with an old patina.
So I designed a drill jig that has a 3D printed body and glued in #41(.096") drill bushings that are on a 10 degree angle. The drill jig locates in the 15th fret with a piece of .015" shim stock in a slot in the drill jig. It is also loosely located on the edges of the fretboard. A soldering iron is used to install a heat set #8-32 threaded insert, and a #8-32 x 1/2" set screw keeps the locator in place.
I had to print the drill jig twice because the 3D printing angled holes and a very thin slot required more clearance than I thought. The .188" diameter drill bushing required a .195" hole for a slip fit, before gluing it in with superglue. The .015" locator required a .021" slot.
The bottom of the drill jig has a 16" radius, clearance for the frets, and locates on the edges of the fretboard.
The drill bushings are set at a 10 degree angle, positioning the drill to enter the fretboard at exactly the center of the 15th fret.
A spring clamp holds it in place for drilling the holes.
The .015" locator fits in the 15th fret slot.
So I designed a drill jig that has a 3D printed body and glued in #41(.096") drill bushings that are on a 10 degree angle. The drill jig locates in the 15th fret with a piece of .015" shim stock in a slot in the drill jig. It is also loosely located on the edges of the fretboard. A soldering iron is used to install a heat set #8-32 threaded insert, and a #8-32 x 1/2" set screw keeps the locator in place.
I had to print the drill jig twice because the 3D printing angled holes and a very thin slot required more clearance than I thought. The .188" diameter drill bushing required a .195" hole for a slip fit, before gluing it in with superglue. The .015" locator required a .021" slot.
The bottom of the drill jig has a 16" radius, clearance for the frets, and locates on the edges of the fretboard.
The drill bushings are set at a 10 degree angle, positioning the drill to enter the fretboard at exactly the center of the 15th fret.
A spring clamp holds it in place for drilling the holes.
The .015" locator fits in the 15th fret slot.