To start the build I have laid out a few options of top wood.
The back and sides will be made from Indian Rosewood and the top will be European Spruce.
A close up of the top and back woods.
European Spruce.
Indian Rosewood.
Getting ready to join them together I use the belt sander to trim the edges of the top blanks.
I am striving to join the top pieces together so that it is very difficult to see the joint. I use this tool to sand the edges to perfectly match each other.
The tool has two grits of abrasive to fine tune the edges.
The blanks are held perpendicular to the sanding surface.
Once I am happy with the fit I apply a bead of glue.
I make sure I have a good even line of glue not to much and not too little.
As the glue sets up I use this tool to hold the two pieces of the top flat while they are pressed together.
The wedges are simple and reliable means applying force.
Before I tighten everything up I make sure the two pieces are coplanar.
When pressed together I get a little bit of glue squeeze out.
Now I turn my attention to the back pieces. Here I am using my drum sander to bring the pieces to a working thickness.
I use calipers to check the thickness.
The side pieces get sanded down to about 100 mils thick. (1 mil = 0.001 inch)
I measure a lot and work very slowly with lots of passes through the sander.
The sides are a bit wider than I need so I trim off the excess and will use the pieces as binding for another guitar.
Getting ready to bend the sides I place the side blank in the heating blanket.
A few pieces of flashing are used to provide a working chamber where the heat will be evenly distributed and I can easily introduce water to the process.
The final piece of the heating blanket is a piece of spring steel that will help prevent the wood from cracking as it is bent. The steel limits the maximum bend possible which helps prevents the wood from being over stressed.
The assembly then goes into the bending machine.
And I squirt a bit of water between the layers of flashing.
After heating up the wood I press the waist into place.
Then the lower bout gets rolled into place.
And the the upper bout gets rolled out.
After the wood cooks for a while and it has taken a set I pull it out of the machine.
To help hold its shape I put it in this fixture until I am ready to use it.
Working on the back again I have chosen a decorative center strip to go between the two pieces of the back.
And the pieces go into the joining tool.
The top and the back.
Here I am cutting a piece of kerfing with the band saw.
I sand a bevel on one edge.
I place the side piece in the form and draw the outline of the side onto it..
And then use the band saw to cut away the excess.
A bit of glue goes on one of the pieces of kerfing.
And it gets glued onto the inside surface of the side. The kerfing is used to provide a gluing surface between the sides and top and back. I use kerfing with a solid strip on the outside. This results in a gunnel like structure that provides a lot of stiffness to the side.
The clamps press the kerfing into the side and the side into the form. This method insures the sides take the shape of the form and as long as the forms have the right shape I can be confident the the sides will have the right shape. I clean up the glue squeeze out with a brush and water.
And then I blow the glue out of the spaces between the kerfs.
Lots of clamps.
After the glue is dry I mount the sides in the form.
And trim off the end excess.
And then I use a drum sander to clean up the inside surface of the sides. No one will see this but it makes me feel good to know that the inside of the guitar is as beautiful as the outside... it helps the notes get out better or so I am told.
And a Dremel tool cleans up the beveled edge of the kerfing.
Back into the forms.
The front edge of the sides have a curve and the heel block needs to match the shape. I trace the shape from the form onto the heel block with a compass.
And the belt sander is used to shape the curve on the heel block.
Now I carefully line up the heel block in the form and place a couple of blocks on the outside edges.
After removing the heel block I cut the kerfing on the inside edge of the guide blocks. The blue masking tape was used to prevent the kerfing from being glued to the sides where the heel will go. This makes it a bit easier to remove the kerfing.
A little bit of fine tuning makes sure the heel block lines up correctly.
And before gluing it in place I trim the heel to close to the width of the sides.
The tail block gets the same treatment as the heel block.
This technique results in a nice snug fit between the blocks and the kerfing.
The tail block gets beveled.
I use my miter saw to create a channel for a reinforcing strip.
Now I glue everything together with "lots of clamps."
While the glue is drying I install these side reinforcing strips in place. This will help prevent the sides from splitting as the guitar goes through its life.
And finally after the glue has had a chance to dry the joined sides come out of the form.
The back of this guitar has the shape of a bowl with a 15 foot radius. The top is flat. The rim of the guitar with its feminine profile has to match the shape of the bowl. To do this I use a large sanding plate with the proper bowl shape hollowed out of the plate. I will run the guitar rim over the sanding plate until I get a good match between the two. I mark the edge of the rim with a magic marker and when I have sanded away all of the marker I know the match is good.
The top flange forces the rim to stand proud of the form so it is easy to slide on the sanding plate.
After a bit of elbow grease is applied the edge of the rim has the right shape and the proper angle.
After shaping the top and back edges of the rim I set up to route out the heel block channel. I use the router table and this special fixture to hold the rim and follow the template.
When I am finished The channel is one inch deep and has the same shape as the heel of the neck. The heel channel will hold all of the hardware for the User Adjustable Tilt action Neck.
Now to make the braces for the back. This template has the same shape as the 15 foot radius sanding bowl. The template guides the shaping of the brace blanks on the belt sander.
After the bottom of the brace is formed I cut the top edge on the band saw.
Three braces.
I use a variety of tools to shape the braces.
After drawing the outline of the back on the back blank I use the band saw to cut it out.
And then I use the go-box to press the braces into place as the glue dries.
I don't know why it is called a Go-Box any ideas?
Here I am cutting out the slot where the braces will get tucked into the kerfing.
Here I am routing out the channel for the rosette in the top plate.
The rosette is glued into the channel so it stands a bit proud and then is sanded flush with the top.
Now I lay out the design on the top plates.
Cutting out the Indian Rose bridge plate. The bridge plate is glued to the underside of the top plate below the bridge.
I use my small disk sander to put a bevel on the bridge plate. No one will ever see it but I think it is important to make the inside of the guitar as nice as the out side. The Gods know.
After cutting all of the brace blanks out I lay them out and then think about them for a while.
After gluing on the bridge plate I cut the top out with my band saw... did I mention that I love my band saw.
I will use the scraps for other parts of the top.
The major cross brace getting shaped with a bit of hand sanding.
Laying out the parts one more time.
A quick tangent. I recently added a CNC router to my tool set and used it to create this contra-rosette. It will be placed on the inside of the guitar right below the sound hole.
Here one the top braces transverses the bridge plate.
Laying out the braces one more time after all of the braces have been shaped.
The braces get glued into place with the aid of the go-box.
After the glue has set up over night I pull it out of the go-box and listen to it ring.
I use my oscillating sander to trim up the sound hole ring.
And here is a brace tucked into the kerfing.
The upper bout is reenforced with a layer of spruce.
And it gets glue in place with the go-box.
To line up the top on the rim I use a fiducial button. Here is a drop of glue on top of the button.
The rim gets placed on the top making sure everything is lined up right.
And the button gets glued to the top.
Now I can glue the top on to the rim without it sliding out of position.
I run a bead of glue around the edge of the rim.
And I use the back flange to press the back into place as the glue sets up.
I clean up the squeeze out with a bit of water and a brush.
After the glue has set up over night I use a trim router to remove the over hang.
Now with the back in place I can install the tail graft so it will line up perfectly with the back strip.
I trim off the end and sand it flush.
A hand drill is used to drill the hole for the neck hardware.
I install the neck adjustment bolt from the rear.
Before I glue the top on I clean it up and make it look pretty. It helps the notes get out of the guitar better.
These inserts make up two of the legs of the neck mount. These two inserts will have set screws that allow me to adjust the neck extension and the yaw of the neck.
Glue is applied the edge of rim.
And the top flange presses the top into place.
I use the trim router after the glue has set.
These two channel wings help hide the space between the top of the guitar and the bottom of the fretboard.
The next step will create a channel for the rib that supports the cantilevered section of the fretboard. The design of the neck attachment method I use allows the musician playing the guitar to adjust the angle of the neck relative to the top. This will effectively raise or lower the string action... you can set it and reset it until you find the action that is perfect for you.
So to do this the neck is mounted on a tripod and the fretboard floats over the top of the guitar. Necessarily this means there is a space between the top of the guitar and the bottom of the fretboard and the cantilevered portion of the fretboard needs to be reenforced. The channel I create with this template makes room for the supporting rib.
The three posts of the tripod are seen here. The upper center line hole is for a bolt that attaches the neck to the body. I call it the "feel good bolt" because it makes you feel good when your neck doesn't fall off the guitar when you change strings.
A few quick pictures...
I think the contra-rosette compliments the rose theme of the rosette quite nicely by any other name ...
I am looking forward to using the CNC router to make some interesting contra-rosettes... should be fun.
Finally I made a quick measurement of the Frequency Response Function up to 460 Hz of the free floating sound box struck at the center of the bridge plate with a lightly padded mallet. This is the spectrum of the sound that results. The amplitude of the trace indicates how responsive the box will be for any given driving frequency.
Now I start to work on the neck. I make my necks from a single piece of Mahogany. This means there won't be any joining lines at the heel and the headstock. I start by leveling the fretboard base using my jointer.
I trim off the end off the heel with the table saw.
And the other face is trimmed with the miter saw.
After drawing the outline on the side of the neck blank I trim up the fretboard face. I spend a bit of time making sure all of the faces of the neck blank are flat and square to the other surfaces. A bit of care at this stage will yield higher quality results later.
Here I am setting up the router table to make a channel for the truss rod.
The truss rod has two way action so we can fully control the shape of the neck. A truss rod is not generally a traditional feature of a classical guitar but I am going to take a bit of engineering license and install one in this guitar. A second benefit of a heavy truss rod is that the additional mass reduces the motion of the neck when the strings vibrate which should improve tone and intonation.
The truss rod adjustment will be accessible through the headstock.
Here I am drilling a hole for the bolt used to attach the neck to the body.
I have set up the router to shape the heel of the neck so it will match the heel channel in the body. I have a fixture that holds the template and and the neck blank.
The aluminum tube sucks up the copious amounts of sawdust.
Here you can see the router bit and part of the shaped heel. Scary router bit!
The template and the bottom of the heel.
Now the heel has the same shape as the heel channel.
I use my milling machine to create the channels for the fretboard support structures and the attachment details.
The inner channel will hold the fretboard support plate and the outside channels act as slots for the wing plates that help hide the slots between the neck and the top plate.
I want to make sure all of the hardware for the Tilt Action Adjustable Neck line up properly. So I use a marking pin in the adjustment nut in the heel channel to mark the spot in the heel for the adjustment bolt holes.
I mount a piece of wood on the neck blank to mimic the fretboard and line up neck in the heel channel.
Then I press the neck into place and the marker pin leaves a hole where the bolt hole needs to be drilled.
I use the milling machine to drill the holes for the adjustment hardware.
I really want the hole to come out in the middle of the heel.
This is the fretboard support plate. The fretboard is not directly attached to the body of the guitar so this plate helps to stabilize the fretboard as it is cantilevered over the top plate.
Everything fits with a bit of room to allow adjustments.
Gluing the plate in place.
Now I am using the drum sander to dimension the depth of the Ebony fretboard.
This is the tool I use to cut the slots for the fretwire. The two templates on either side of the rail set the placement of the guide sled.
My Dremel tool has a saw attachment that cuts the slots.
The saw is used as a stop that sets the position of the guide sled and the saw runs along the face of the sled.
The roughed out fretboard with the slots.
I mount the fretboard blank on a flat surface and then level out the top of the blank with a set of precision sanding blocks.
I use masking tape to mark the outline of the fretboard.
Here I have set up to install the fretwire. I am using a fretwire that looks like gold so it will match the tuning hardware.
I cut the fretwire to length and then gently hammer it into place. I check carefully to make sure the fretwire is fully seated to the fretboard.
CLM 1.2.59 Build
Laying out the neck.
I use a small drop of cyanoacrylate glue on the end f the fretwire to make sure the wire won't wiggle free.
I install a small wood plug to cover the end of the trussrod. This will provide some wood for the trussrod cover plate screw to bite into.
I cover the rod with thin tape to seal the gap between the rod and the wood. This will prevent glue from getting into the works when the fretboard is glued on.
I cut a 3 deg draft angle into the heel. This will ensure free motion of the heel in the heel channel as the neck angle is adjusted.
I use fiducial buttons to guide the placement of the fretboard on the neck blank when it is glued on. The bone blocks provide temporary limits as the button is glued in place.
The button is cut so it is a bit proud of the surface.
I put a drop of glue on the end of the button and press the fretboard into place.
The button sticks to the bottom of the fretboard.
I use two buttons on the fretboard. After the buttons are sanded down so they won't bottom out in their holes the fretboard can be accurately placed on the neck blank. This system means I can position the fretboard on the neck blank before I glue it up. It is difficult to position the fretboard accurately when the glue is wet slippery and messy.
I use epoxy to glue the fretboard to the neck blank.
With the fiducial button system the fretboard and head plate drop right into place.
And all I have to do is clamp it up.
After the glue has set I heat up the glue squeeze out and scrape it away.
Here I am using the milling machine to put a flat surface on the back side of the head stock. I want to make sure the headstock has the proper thickness and that back side of the headstock is parallel to the top side.
And now The belt sander is used to profile the throat of the neck blank..
And the heel.
I use the bandsaw to trim the plan view outline.
And then the router table with a roller glide bit trims the edges to shape.
I tape (really strong double sided tape) a template on the headstock and trim the headstock to shape.
The milling machine is used to route the slots in the headstock.
And the milling machine accurately drills the holes for the tuning machines.
With the accuracy the milling machine provides the tuning machines dropped into place ~perfectly.
I like to look at the guitar from time to time.
I use masking top to keep make where I don't want to remove any material.
And now all I have to do is carve away everything that doesn't look like the neck.
I have learned to go slow slow slow. It is much easier to remove wood than to put it back.
I made this multi-contour gauge bracket to help me visualize the shape of the neck profile. I continue to work on the neck using a variety of tools until it looks right feels right sounds right and measures right.
This is the User Adjustable Tilt Action Neck hardware.

CLM 1.2.59 Build

Classical Model Build Thread