Author: g.b. hembree

After gluing in the neck, we can finish off shaping the neck, heel and button. We then do the set-up, which involves making and installing the saddle, reaming the holes for the pegs and the button, cutting a sound post and bridge and finally stringing it up.

I never ceased to be amazed at how the tone of a new violin changes over the first few days as the stresses relieve and the instrument “gets used” to being a violin. When I first play it, it never sounds very good. You can tell whether it is going to be good or not but it is very hard to resist fooling around with the set-up to see if you can make it better. After 45 minutes, the tone improves 100%. Everything starts opening up a little bit. After several hours it is like a different instrument. This goes on for several days until the tone finally starts to stabilize.

It has been about a week now and I have to say “The Edward” is amazing! Maybe the best ever. The tone is full and powerful and very even across all of the strings. I can’t stop playing it. I’ll leave it in-the-white for a couple more weeks while I work on a bow commission but then I will take it down and varnish it. Below are some pictures of the completed instrument.

I am very pleased and I’m sure Ed will be as well.

With all of the pieces made and the body assembled, it is time to make a neck for “The Edward”. The first step it to plane the neck block so that the width is 42 mm and the two sides are perfectly perpendicular to the face.

Then using our template we layout the neck on the block.

Using the bandsaw and the drill press we cut out the outline of the neck and drill the peg holes. Using knives, chisels and files we clean up the cut-out. We are now ready to carve the scroll.

The first step is to remove the waste on the outside of the peg box. We first use a saw and chisel to remove the waste wood.

Then the whole thing is then cleaned up to the line.

The next step is to carve the first turn of the scroll. We do this by using a saw and chisel to remove the waste.

We clean this up to the line and do the same thing for the second turn.

Finally, we under-cut the volute, complete the inside of the peg box and flute the scroll. The scroll is now complete and we are redy to finish off the neck.

The last step is to prepare and attach a fingerboard and nut and remove the waste wood from the neck.

We can’t completely finish the neck until after it is attached to the body but we can shape most of the neck and finish off the chin of the scroll. We are now ready to attach the neck to the body.

The making of the top goes generally along the same lines as the back. We join the two pieces of spruce and trace the outline from the rib assembly. The outline is cut, shaped and a purfling platform is established.

The purfling channel is then cut, the purfling installed and the outside arching shape is carved.

Finally, we turn the plate over and gouge out the inside. Using planes and scrapers, we thin the plate until it has a uniform thickness of about 3.5mm.

The next step is to tune both the top and back plates. Then we will cut the f-holes and install the bass bar in the top.

We are now ready the make the back for “The Edward”. We start off by joining the two pieces.

The rib assembly is clamped to the joined pieces and the outline is traced with a 2.5mm offset. The back is then cut out just proud of this line.

Next, we establish the purfling platform, trim the outline to the line, cut the purfling channel and bend and fit the various pieces of purfling.

Here is a close-up of the purfling channel.

The purfling strips are glued.

For the final step, we use templates to shape the arching, cut the channel and use scrapers to clean-up everything. Notice the beautiful flame in the maple.

Finally we turn the back over and gouge out the inside to nominal dimensions. We set it aside for now and start the top.

I am starting a new violin, “The Edward”. This is commission from Ed Lawrence (former Principal Violist with the Houston Ballet and Opera Orchestra). Ed has chosen a Strad model and picked out the wood to use from my stores (notice the beautiful flame in the maple for the ribs and back).

We will start with the rib assembly. Blocks are cut and glued to the mold. The blocks are then shaped to the outline of the violin. The ribs are planed to a thickness of about 1.2 mm, bent and glued to the blocks. Linings are cut and bent and inlet into the blocks. The picture below shows the rib assembly with linings ready to be glued in place.

The linings being glued in place.

Finally, the points are trimmed to size, the back is flattened and the top of the assembly is brought to proper dimension (32mm at the bottom block and 30mm at the top).

With the rib assembly done, we move on to the back.

A couple of years ago, I made an Andrea Guarneri model viola for Ed Lawrence.

Ed used to be the Principal Violist with the Houston Ballet and Opera Orchestra. He now has a thriving teaching business in Houston. Ed was kind enough to let me record him playing a brief clip. Click below to see the clip.

Ed Lawrence – Playing Andrea Guarneri Model Viola

Beautiful!

Now that all of the individual pieces are done, we can start the assembly process. The first step is to remove the rib assembly from the form and clean up the blocks. We then cut a small chamfer along the bottom edge of the top and bottom plates. We are now ready to glue together the corpus.

We begin by gluing the back to the rib assembly. Next, I like to seal the inside of the corpus with a very thin coat of porpolis spirit varnish. I then glue in a lable. The top is ready to glue to form the corpus.

With the corpus done, we can now fit and glue in the neck.

We can now finish off carving the heel and button and blend it into the rest of the neck. We can also do the first pass on all of the edge work.

There is still quite a bit of clean up work to do before we can varnish “The Rebecca” but before we do that, let’s set it up and hear what it sounds like!

With the plates tuned, we are ready to cut the f-holes (my favourite part of violin making) and install the bassbar (my least favourite part of violin making). To start with, we layout the f-holes and cut the “hole” part. The layout is very critical because of the relationship between the location of the f-holes and the location of the bridge.

Now we take a hand saw and cut out the f-holes leaving plenty of room for carving the final shape.

Finally, using very sharp knives, we cut the final shape of the f-holes until they are dimensionally correct and have an elegant flow of lines.

Next, we put in the bassbar. This operation is extremely critical to tone and so must be done in a very exacting manner. Its location is critical to bridge placement and it must fit exactly along its entire length. Notice the red chalk I use for fitting.

With the bassbar glued in, we shape it and tune the plate again (sorry I don’t have pictures of the tuning). Finally, we glue in some re-enforcing cleats and the top is done.

We are now ready to assemble all of the pieces.

We are now ready to tune the top and back plates of “The Rebecca”. My method of plate tuning is based upon the work of Carleen Hutchins. Carleen spent a lifetime researching the relationships between the various resonant frequencies of free-standing violin plates and the tone of the resulting violin.

I look primarily at two modes of vibration for the free-standing plates. The first is F5 or the ring mode. The second is F2 or the x-mode. These two frequencies are directly related to the flexural stiffness of the plates. Contrary to Carleen’s recommendation, I don’t tune the plates to a specific frequency but rather try to tune to a specific flexural stiffness. This is demonstrated below.

The set-up I use for vibrating the plates is shown in the image below. On the left is a speaker mounted on a platform which holds the violin plate (note it is rested on foam blocks). As a signal source I use an ipod with a signal generation app. To boost the signal to a high enough level to drive the speaker, I pass the signal from the ipod into a pre-amp (just a di box) and then into a power amplifier. I sweep the signal generator until the resonant frequency for the plate is reached at which point the tea leaves dance around and line up along the node lines.

Below are two images for the back plate. The first is F5 and the second is F2. Notice how the nodes lines are not very clean especially for F2 in the upper bouts. This tells me I need to remove some more wood. The shape of the node lines gives me some idea of where to remove wood. Also this plate is a little heavy and stiff. I use the resonant frequencies of the two modes (in this case 370 Hz and 166 Hz) and the weight of the plate to calculate stiffness. Finally, the other thing I look for is the range of frequencies at which the tea leaves vibrate. For this plate at this point the range is about 10 Hz. When I reach the optimum graduation that range will be more like 3 Hz.

The next two images are the final results for the top. Notice the nice clean nodal lines. The difference in shape of the ring mode is due to the different graduation pattern used for the top and back. The back is significantly thicker in the middle than in the lungs. This causes the back to act like an air pump and results in the rounder shape of the ring mode. The top is more uniform in thickness and hence the dipping in the middle of the nodal lines for the ring mode.

With the plates tuned, we are ready to cut the f-holes in the top and put in the bassbar. I will use the tuning setup one more time to tune the shaping of the bassbar.