Thicknessing Jig for Peg Head

[Todd Stock]

This is the second version of this jig, with the first being a full adjustable jig that could be finicky to set up. The current version is designed to produce a parallel rear peg head surface and mill the outline of the dart/diamond volute/neck transition at the same time. I use one of these for each different peg head I make - the time spent on laying out and making up a unique base plate is a one-time event and avoids swapping the neck templates (the 1/2" MDF or phenolic template the bushed router rides against to mill the volute).

The box is made up of an 8-1/2" square x 3/4"/18mm hardwood ply base plate, the 3" deep x 3/4"/18mm side and end pieces, and the template (the one shown is 1/2" MDF). 1-1/4" Phillips head deck screws are used for assembly and to mount the the neck to the base plate.

Make:

1. Cut 3/4" hardwood plywood base plate to 8-1/2" square, strike centerline, and lay out peg head outline and tuner while locations full scale (if the edge of the plywood is treated as the end of the fretboard in layout, the jig will take necks both with and without fretboard already installed.

2. Through drill at tuner hole locations with 3/16" brad point bit (a larger bit can be used, and this will allow some variation in tuner hole location; however, the practical limit is about 1/4" if standard 1-1/4" deck screws are to be used). For slotted headstocks, lay out the slots (centerlines and end points(, then lay out two mounting screw holes in each slot set 1/2" in from the ends

3. Mill out 3" by 30" of 3/4" hardwood ply for side and end pieces (these may be three pieces of 10" stock or single 30" piece. Mill an 1/8" deep dado 1-15/16" from one edge and just wide enough to accept the base plate.

4. Cut two side pieces to 9-1/2" length and Install with two 1-1/4" countersunk deck screws per side

5. Measure and cut the end piece, and install using two 1-1/4" deck screws into the base plate and a single screw from each side to end piece.

6. Mill up desired 1/2" MDF or Phenolic template with edge allowance for 5/8" guide bushing (this is usually a 1/16" offset for a 1/2" straight router bit), and - using the marked centerline and peg head layout on the base plate, install the template with four 1-1/4" deck screws.

Use:

1. Drill the tuner holes (solid peg head) or mounting holes (slotted peg head) through the peg head veneer, but no deeper than 1/8"...these will be through-drilled (on solid peg heads) or milled away (on slotted peg heads) after the peg head is thicknessed.

2. Pilot the tuner or mounting holes with a 3/32" split-point bit for mahogany necks - the dimple left by the brad point is adequate for the purpose. Use an appropriately-sized bit to pilot in maple or other harder woods.

3. Mount the neck to the jig with a 1-1/4" deck screw per tuner hole (solid peg head) or mount hole (slotted peg head)

4. Install an oversized base with 5/8" diameter bushing on a fixed base router. Set the 1/2" diameter straight bit to trim the back of the peg head to .025" greater than desire final thickness (a shim of this thickness and final thickness is handy for setting depth), then take final pass at desired depth.

[Brian Evans]

Thanks for sharing that. I think my next project will actually be making a number of router jigs. I will be making a router sled to let me thickness and true up boards up to 24" wide and 7 feet long, a sled to let me radius fretboards, etc. I really want to make a copy router - I have this desire to not fully hand carve a hard maple archtop back if I can help it....