making the bridge part 2

Cutting In All the Parts

cutting the saddle slot

saddle slot is done

drilling the string pin holes

milling the edges of the pyramid.  The rest of the pyrimid will be shaped on each end by hand using files and rasps and sand paper.  But I like to get this break between the pyramid ends and the part that holds the pins and saddle real clean.  The Miller does clean work.



gotta make a bridge for Lyndsay

The Bridge blank.  It a piece of Brazilian Rosewood that is a tad over 6 inches long and a hair wider than one inch

Her I lay off the center line and mark off the position of the outside strings

This ruler marks off the string spacing on the bridge, which will be 2.25 inches, but it allows for a little more space between bass strings and a little less between treble strings.  The gaps between strings should be equal 

Belot you see the confusing array of lines, the center line, string spacing lines (where I will drill the bridge pin holes. and the limiting lines for the saddle slot, and finally the only lines that go all the way across the bridge showing the limits of the center section of what will be a pyramid bridge.

This metal milling machine is what I use to make the saddle slot.  There is a 1/8th bit in the chuck

In the holding vice I tip the bridge forward some so that the saddle slot is angled back a little.  (about 2 degrees)  This has several benefits, not the least of which is that the scale length is longer by a fraction the higher the string action.  Since high string action needs more compensaton, this automatically does the deed.

Some action shots of the slot being cut and other things on the bench next installment

Binding channels

 Here is Bob's Zircote OM in a holder.  The device on the far edge of the guitar is a laminate trimmer with a ball bearing guide and carbide bit that will cut the binding channel.  The cutter is held in a vertical column so that it rides up and down vertically.  I turn the guitar under the cutter to cut a grove in the edge for the binding.

Here you can see the channel cut in the side of the guitar

I can never seem to get the sides to come out exactly flush on the end.  This gap will be cut away by the next operation, so the only problem the gap presents is that the cutter shown above, which uses the sides to reference the cut, might dip into this gap and make an uneven channel.  So, to overcome this minor irritation, I usually just super glue some balsa into this gap.  The balsa fill provides an even surface for the cutter bearing to ride against.  No uneven binding channels

This shows another channel being cut, right over where that gap was in the picture above.  This channel will have a piece of decorative wood glued in place to tidy up the joint and look purty

This is what that channel looks like.  Tomorrow I will glue in the End Graft into that channel

Lyndsay's guitar body back from the finisher

I have my guitars finished by a guy who makes his living finishing guitars.  No kidding.  That's what he does.  He is better at this part of guitar making than I am so I get him to do it.

In fact, I think he is better at this than anybody, and I have seen a few guitar finishes.

rope purfling

Crazy Koa back and sides with Brazilian RW binding, and maple/walnut purfling lines

I am still doing a little touch up work on the neck, but this guitar will be out the door in a few weeks.

You can see the mortises that I put in the top to facilitate neck removal.  You can see the sound port on the side of the guitar that acts like a monitor for the player and some how enhances the sound out front as well.



preparing the mahogany 000 for closure

This is Dave's mahogany 000 guitar. 

The top is cylindrical rather than spherical so the edges of the sides must be sanded to a cylindrical shape.

I do this on a cylindrical work board with sand paper attached.  Just rub the sides back and forth until the edges are true.

mission accomplished.  Here again you see the laminated linings and side and back braces inlet into those braces

View of the top bracing pattern.  Lots of scalloping here

putting the back on Bob's zircote OM

The back edge of the rim needs to be shaped into a spherical contour to accept the back.  The back is of course shaped into a spherical contour.

This disk with a spherical contour has sand paper attached.  It spins, powered by an electric motor and the edge of the rim is ground to the proper contour

This interior shot shows the back glued on and cleaned up, more or less.  A little sanding needs to be done to clean up the marks

Gluing on the back.

Top glued on mahogany guitar