Maguire Guitars, Shop Tour Phase 7
Assembly and Set Up of a Custom Built Guitar
These guitars are ready for for set up. This starts with cutting the nut. I like the nut to fit nice and tight. I mill to about .020″ strong and sand and polish to final thickness. The nut should snap fit into its channel and the bottom of the nut needs to be absolutely square and make 100% contact with the neck. This is a bone nut blank in the milling machine, getting milled to proper thickness.
This is a water buffalo horn blank getting the same treatment.
One side of the nut is cut and polished.
The other side is cut and polished and the top is beveled at the same angle as the string break which is about 13° on this guitar.
Here is the bone nut after preliminary shaping and some slotting. The string slots are wide enough to accommodate up to 12ga. strings. At the moment the string slots are left a little high and will be dialed in after fretwork.
Fret leveling with a leveling jig. This is a shop made set up/leveling jig. The guitar gets strapped into the jig and strung up to concert pitch. The dial indicators read the back of the neck and are set to zero. This will allow me to return the neck to this exact position allowing unfettered access to the frets during a simulated set up.
While unstrung, string tension is simulated by manipulating the jack screw up at the back of the headstock and the strap down at the nut until the dial indicators go back to zero.
The fretboard is taped for protection. Now the frets can be leveled without guesswork. Sometimes no leveling is necessary. Usually a few frets need attention, so I kiss the tops with a radius sanding block until every fret has been hit. After leveling, the frets are re-crowned and polished to a high gloss.
I then de-burr and roll the fret edges with a file and successive grits of sandpaper to a nice smooth feel. I roll the edge to give the guitar that “broken in” feel, like it has already been played for decades.
Custom pickup rings.
My friend Don Williams cuts these for me on his CNC. Even still, they take lot of hand fitting and finishing. The bottoms must be contoured to match the tops, the angles have to match the string angle and the heights have to be such that the tops are in line with each other. Edges get sanded, rounded over and polished. Screw holes get countersunk and pickups installed. This can add up to several hours of work per pair of rings, but man, they are sweet. Here’s some ebony rings getting sanded on the master template to contour the bottom and dial in the angle.
Total ebony upgrade. Pickup rings, tuner buttons, switch tip and pot knobs.
These are ivoroid rings for the tobacco burst with pickups installed.
I like the electronics cavity to look as neat and tidy as the rest of the guitar. The cavities have been painted with 2 coats of Electrodag shielding paint. I plot out the wiring paths so that things can be easily traced by future luthiers. Each individual component can be addressed without much bother to the other components.
I use vintage style cloth wire because it’s easier to work with and doesn’t melt from the heat of the iron. Here I’ve used PEC potentiometers and NOS oil in paper caps. These components typically have values of +/-15%. In order to get the most out of this fortunate imperfection, each component is tested for it’s true value and thoughtfully selected for placement. Higher values are used for tone pots, bridge p/u gets highest value, neck p/u gets next to highest. Lower values get used for volume pots. Higher value caps get used for bridge p/u and lower values for neck p/u. This is my standard Meridian layout. V,V,T, 3-way selector, coil tap and phase switch. Many tones to capture with this setup.
Here is a typical V,V,T,T, 3- way selector (not visible in this photo). Note at the top of the cavity, left of center you can see the bottom of the bridge post bushing just barely breaching the cavity. This is by design and allows me to ground the bridge with no problem.
This is The Meridian semi hollow body in the process of wiring. This one gets a Graph-Tech Reso-Max GHOST piezo bridge pickup. This requires a circuit board, a battery and a whole mess of wires. This was a very challenging wire up due to the lack of a control cavity cover, but with plenty of forethought and a solid plan it worked out perfectly. In this photo you can see the hole drilled under the bridge to chase the individual piezo saddle wires into the access cavity.
Here is the GHOST circuit board and only some of the wires that need to be worked into this system.
These are the body mounted components. They will need to be fed through the body and out through the bridge pickup cavity access.
All the wiring to the circuit board is done and tidied up. Now the board can be tucked into the access cavity routed under the bridge. Ready to install the pickups and wire them into the selector switch.
Wiring is complete. Note the circuit board tucked into the access cavity, and the custom ebony stop block which tames the wires and keeps the board from rattling around.
From this angle you can see the 9v battery tucked into the access cavity between the 2 pickups. This also gets an ebony stop block, keeping it from rattling or sliding around.
All done! This is set up with a stereo output with smart switch sensor. 3-way selector, master V, master T for the magnetic pickups and a blender pot with center detent to infinitely mix between magnetics and piezo.
Now it’s time to finish the nut. The string slots are brought down to the proper depth, the nut height is taken down to half the height of the strings on the bass side and the full height of the strings on the treble side. The back edge is shaped, and the corners are well rounded. With the rounded corners and high polish, the nut is never noticed by the hand when forming some of those acrobatic chords in the first position. The nut is secured in place with 2 small drops of glue and clamped with the pressure of the strings. Here’s some nuts fully slotted, shaped, polished and ready to go. I typically use vintage, unable ached bone for Certified 7’s and either water buffalo horn or Graph-tech’s Tusque for Meridians and Contemporaries.
After fresh strings, intonation and action adjustment, the last thing to do is plug ’em in and tear ’em up. The pickups need to be dialed in. I adjust the pole pieces for equal volume. The neck pickup is brought up to within 1/16″ of the strings when fretted at the last fret and the bridge pickup is adjusted to match the volume of the neck pickup.
That’s it, we’re done!!! Case ’em up and send em’ off to their new stewards.