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In this thread I will be updating progress on my current build, a Lutz/Bubinga OM-Sized steel string.
This will be build #10.
This build is special for me in that it will be a birthday gift to my oldest brother, who was my mentor in many ways growing up.
Most of the materials came from Shane at High Mountain Tonewoods.
The Pomelle Bubinga is especially sweet - I am looking forward to seeing it under finish.
For the other materials, I will be using Lutz braces, Spanish Cedar for the neck, Ebony/Maple for the binding, Bubinga/Zipflex for the rosette, Bubinga for the headstock and Ebony for the backstrap.
The tuners will be the Cosmo Black 510's, the fretwire will be EVO Gold.
The dimensions will be OM: 15" lower bout, 4 1/4" deep at the tail, 24.9" fretboard, joined at the 14th fret.

I have basic hand tools, and have built a number of jigs, but stumbled onto a sweet deal for a dual-drum thickness sander which sees a lot of use.

Thanks for looking!


Rob's Lutz/Bubinga Build on Photobucket

Looking good Robbie!

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Bobby Masten

I like the work , very nice and looking great . 1 question . I saw a jig made like a guitar that had dowels all the way around sticking out couple inches . whats that jig for ?

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It looks like something I see in Todd Stock's pictures. It's for clamping the bindings on. Instead of wrapping all the way around the guitar, you just work from the one side. I'd like to hear more about it too.

Mike

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Mike Lindstrom

Thanks guys! Before I had a go-bar deck and outside jigs I used the solera and the paper-cork spacer as per the Cumpanio method to build.
He recommended cutting an inner tube into 1" wide lengths to use to clamp the back and top on during installation, and for clamping on the bindings.
It proved to be amazingly cumbersome to pass the rubber strips under the solera, , so I drilled holes and installed the 3/8" dowels so I could just hook the rubber band there and stretch it across....way better....

OK, here are some pix to get this thread up to date:

The initial side thickness is about 1/4" - here I am thicknessing on the drum sander to 0.085" in preparation for profiling and bending

For the back plates, Once the center seam is perfectly square and straight, and thicknessed to .105", I glue them together on a flat surface, covered with waxed paper. The level keeps things flat. Note the simple wedge and block system to apply pressure to the glued seam

The 8mm x 16mm Lutz Spruce back braces are marked to a 15" radius, then planed to that shape with my Veritas Low-Angle block plane on a shooting board. Very slick. It only takes a few minutes to profile each brace. (Thanks Mario!)

The back braces are shaped and sanded, and the label is glued on. It is customary to use only paper from European Spruce pulp and attached with glue derived from pregnant Andalusian sheep, otherwise tone will be affected....

More pix to get this build thread up to date:


Heel and Tail blocks clamped into position



Here is the Radius Dish (also from High Mountain Tonewoods) in action - it has two profiles - 15' for the back, and 25' for the top. As I am shaping the back the 15' radius is down. I rotate the dish back and forth (aka "driving the bus") until the sides, tail and heel blocks are evenly sanded to the 15' radius.


Now that the sides are profiled, the kerfing installed and profiled, we are ready to install the back. Here I am marking the position of the back braces in preparation for notching out the pockets. Note the green tape so I can clearly see the marks.


After notching the brace pockets and doing a test fit, I run a bead of glue (LMI white) on the kerfing and heel/tail blocks, then fit the back and apply clamping pressure with the go-bar rods.

The Lutz Spruce top is a hybrid of Sitka and Englemann Spruce and only grows in an area near Terrace BC. The tonewood was hand-picked from Shane's stash at High Mountain Tonewoods. Lutz Spruce is well regarded for its tonal properties - some well-known builders use this tonewood on their very highest grade of guitars (e.g. R. Taylor, Greven) The top is prepared and joined in the same way as the back.


In preparation for routing the rosette channel, I have laid out the rosette and sound-hole on the top, then drilled a 1/4" hole at the center of the sound-hole. This guitar will have an inner rosette 1/4" wide of Bubinga, surrounded by Blue Poa Zip-Flex. The outside rosette will be 3mm BWB purfling.


Here I am using my shop-made precision router base (Wells-Karol design) to route the 1/16" deep rosette channel. The precision router base and the amazing Ridgid laminate trimmer make this operation a breeze.


I have cut the rosette channel and cut the Zipflex to length - this is the first fitting - came out nice and tight! You have to be on top of your game for this step - pretty easy to mess up a measurement and destroy a Lutz top - to be avoided!


After cutting the scarf joint, I flip the headstock piece over and plane the surfaces perfectly flat with my low-angle block plane.


To glue the scarf joint, I turn the neck sideways, cover my work board and cauls with wax paper, apply a generous film of LMI white glue and clamp it up.


And this is where the build is at today - back and sides are completed and in the mold, the rosette is started (there will be a delay as I am out of B/W/B for the outer rosette ring....doh!) and the neck is started with the scarf joint glued up.

Here is the cleaned up scarf joint, with plenty of room for the headstock shape.


From the scarf joint, I have laid out the 3/16 nut, 14 frets to the body join, then another 7/8" for the tenon. After verifying measurements I cut the neck to length on the 7/8" line.


To create the stacked heel, I use 3 pieces of Spanish Cedar, 3" x 3" x 7/8". The vertical block on the left and right of the stacked heel are for lining up the stacked heel prior to clamping - the stack slide all over when wet with glue.

Progress on my top is currently paused as I wait for my order of BWB purfling for my outer rosette ring to arrive.
So, I am doing a bit of work on the neck:


At the 14th Fret mark I mark the 3/4" Tenon, allowing for a slight angle at the cheeks of the heel, ensuring a snug fit against the guitar body


Here I have drilled two 10mm holes for the 1/4" Knock-Down barrel nut.

The build has been on hiatus for a few days as I have been waiting for my outer rosette purfling to arrive....
So just for fun I built a Williams-Style binding machine:

The purfling arrived, so....

Very cool . Wondering if you just made your binding cutting jig by sight or is there a build description that's available to look at. I'm toying with building one myself, just trying to figure out what to do.

Thanks,

Thanks Jeremy!

Please see my post on building the Binding Machine in the Fixture, Video and Picture Tutorial section:
http://www.luthiersforum.com/forum/viewtopic.php?f=10117&t=30375
Shoot me a note if you have any questions.

Rob

The Scroll Saw is used to cut out the rough profile of the top before bracing - I go about 1/2" larger than the guitar profile

A shooting board is used to shape the braces. I trace the 25' profile on the side of the brace then use the shooting board and my low-angle block plane to profile the bottom. I always finish with one long pass. This is the longest brace - the x-Brace.

After creating the 25' profile on the bottom of the brace, the notches are cut out as shown. Note the top is now on the 25' radius dish, which is covered by 3 layers of newspaper to protect the top from the sandpaper.

Gluing the X-Braces

The profiled braces are now all glued in. My X-Braces and UTB are 8mm x 16mm, the Tone Bars are 7mm x 13mm, and the finger and sound hole braces are 6mm x 7mm

The bridge Plate is made of 0.100" hardwood (in this case, East Indian Rosewood), with the grain at a bias to prevent splitting from the string ball-ends. It is made 1/8" larger than the actual bridge, and butts into the X-Brace

I have removed the radius dish and am gluing the Upper Transverse Brace against a flat surface, as it is not profiled. This technique, along with flattening the upper bout, help create the desired neck angle.

I have scalloped and shaped the braces, and have installed the fingerboard extension block that butts into the upper transverse brace. The top is signed, and ready to install!

In preparation for gluing the top, I have marked and chiseled out the brace pockets, then cut the brace ends to fit into the pocket.
For marking where the braces meet the side, because the mold is in the way, I use a 1/2" length of sharpened pencil lead and needle-nose pliers.

After test fitting the top then scraping the mating surfaces with a razor blade, I have laid down the glue line and installed the top, using the Go-Bar deck for clamping pressure

Out of the mold, and the sides have undergone a preliminary sanding to ensure the sides are smooth and flush with the top and back. This is required to ensure the binding channel is cut accurately, as the cutter bearing rides against the side profile - any irregularities will show in the binding cut.

Twins! I am building a nylon string in conjunction with this build - they are now at the same state - ready for binding

The "cheeks" of the tenon are angled slightly to ensure a tight fit against the guitar body. I cut out the tenon with my Veritas crosscut saw

I trace the shape of the heel, cut the two large blocks out, then cut radial lines to the curve, and remove the excess. (this is the one time I pine for a bandsaw)

The curve is smoothed to the line on the spindle sander

The headstock veneer is bubinga, with a black veneer sandwich. I have clamped the headstock template to the bubinga veneer to set the saw angle - which will butt up against the nut.

Nice progress, Robbie. Looking good!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Thanks Waddy, coming from you, that is high praise indeed!
I have followed your builds with interest when I started (less than 2 years ago) - many of the techniques I use now are derived from the rich content of the forum and good old trial and error....
I am having a ton of fun with this build - it is my first commission, #10, and the very best kind, from the wife of my brother, and is not due for another year!
Lots of time for do-overs...hahaaa!
One tool that I do not have is a bandsaw - others swear by it, but not having one, and never having used one, I have found (labor-intensive) workarounds to situations where one may have proved useful - such as the roughing out of the heel. I love every second of it...

Rob

You started 2 years ago? Only 2 years? You fooled me...

Thanks for taking the time to post. I love to watch and learn from these threads.

Only two years? Well done Rob!!!

_Mike

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_Mike Tracz
MCT Guitars
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To prepare for gluing the bubinga/black laminate faceplate, I first tape and clamp a fence block at exactly the intersection of the scarf joint. The leading edge of the nut, and start of the scale/fretboard will be 3/16 away from this line as previously laid out. Glue and clamp, ensuring the sandwich is firmly seated to the fence block. Once clamped, I remove the fence block and cleanup the squeezeout.

I cut the 1/4" double-action truss rod channel on the router table, ensuring the length of the truss rod is shy of the nut, and is seated nicely in the tenon. Remember to file down the welds if applicable.

If the truss rod is not perfectly flush to the neck surface at either end, a good trick is to cut pieces of metal duct tape and stick to the bottom surface of the rod in layers until it is perfect. I glue it in with a drop of thick-viscosity CA at each end.

I do my neck fitting before binding, to ensure everything is 100% aligned before cutting the binding channels.
After a light sanding of the upper bout to ensure it is perfectly flat, I am checking the neck angle to the saddle location - I am aiming for 2.5mm airspace at the saddle.

I then measure the neck angle with an adjustable angle gauge:

And transfer to the heel:

Note I have shaped the bottom of the 3" tenon - to get the correct radius I used a 5/8" OD washer which matches the 5/8" pattern bit I use to cut the mortise.

To cut the mortise, I mount the guitar body in the troji, and use a carpenters level to ensure the centerline is perfectly plumb.
I then use the level to ensure there is a 2 1/4" flat area at the mortise location that is perfectly level. I sand as required with a flat sanding block. This step will greatly ease the upcoming neck fitting. I then mark the mortise, which is 3/4"w x 3/4"d x 3" long. A good tip is to scribe the soundboard to avoid tearout.

I install my mortise cutting jig on the troji, ensuring the top is perfectly level, and aligned to the layout. I also clamp a fence at the 3" mark (from the bit to the outer edge of the router base)

Using a 5/8" patterning bit, I make 3 passes at 1/4", 1/2" then the final 3/4" deep

Here is the cut mortise - centered and square

First fit (woohoo!)

Carving the heel:

First step is to lay out the centerlines and heelcap shape

Then the sides are ramped in a straight line, just shy of the layout lines

The cheeks are then carved

The Primary Facet is carved, which starts at a 45 degree angle to the centerline at the
heelcap. just shy of the layout line

The Secondary Facets have been carved, which take a tiny bit of material from the primary face to the centerline and just shy of the cheek line. I have already begun smoothing with my needle files

The carving is done, no big blowouts - ready for fitting!

Robbie, you're smoking along! Way to go.

Looking great! Nice adaptation to the troji there! I really like it

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Thanks Rod, I am having a blast with this build!
And thank you for posting the Troji plans - that has to be one of the best additions to my shop.

Rob