Gluing on the back

Next I cleaned up the back and rounded the underside of the edges before gluing to the ribs using my homemade violin clamps.

Taking out the mold

Once dry i then broke the glue joints holding the blocks to the mold by tapping firmly with a hammer and then carefully pulled the mold out.

Fitting the linings

Once the mold had been removed I fitted the linings to the front side just like for the back and then trimmed them to a nice chamfer with a sharp knife.

Carving the blocks

 I used a gouge to trim up the blocks taking as much as possible off without weakening the instrument.

Then a final clean up to get rid of any glue traces before gluing in the label.

Fitting the saddle

I carefully marked the position of the saddle on the top with a scalpel and then deepened the cuts to complete the cutout for the saddle making sure the fit was not too tight.

Gluing on the belly

I then carefully filed the inside of the edge curve on the belly and  after making a few marks to line things up properly I glued the top on cleaning up any squeeze out with a hot water soaked rag.

When dry I shaped the saddle to fit and glued in.

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Plate tuning

Having managed to get to the initial graduations I am finally able to start the plate tuning.

First I took stock by weighing the plates and measuring mode frequencies.

Equipment

I used the same setup I used for the cello:

• Android tablet to generate the signal tone
• 20W class D amp
• 4″ driver unit (used an 8″ on the cello)
• Tea-bag for tea leaves

Starting point with initial graduations

The top weighed in at 88g and had perfectly matched x-mode and ring mode (an octave apart) but still a bit high as expected at this stage.

The back weighed in at 119g and is still quite a bit too stiff with the ring mode going off both ends and not closing. The x-mode frequency needs bringing down quite a bit to get to an octave below the ring mode.

After a bit of work I managed to match the back and top  ring modes an octave above the x-modes at about 180Hz.  The plates are still a bit heavy but this gives me something to work with when tuning the bass bar after cutting the f-holes.

F-Holes

I marked out the outline of the f-holes using the printed paper template I had designed and pricking through with a pin to mark the outline on the top. I then drilled the top and bottom holes with a forstner bit and opened them up to correct dimensions with  the reamers I use for peg holes.

With the top carefully clamped to the cork faced form, I used a fine toothed coping saw to cut a rough outline and then carved off the excess with a scalpel.

First results are shown here but still needs a bit of fettling to get the two holes balanced.

Bass Bar

Next I sliced up a nice piece of quarter sawn spruce on the bandsaw and sanded down to 5.5mm wide on the drum sander.  I cut this to length and marked the underside profile with a pencil using a block of wood while the blank bar was gently clamped in place on the belly.  Then I planed the underside profile down to the pencil lines and chalk fitted to the inside of the top aiming to get the outside edge of the bass bar 1mm inside the outside edge of the bridge foot with a 2mm slant outwards from top to bottom. 

After gluing in the bass bar I tuned the bar to match the top and then gradually worked both the top and back down in frequency to match each other and get as low a weight as possible (my client wants a light easy to play instrument) with the ring tones just below F.

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Joining the violin plates

So to the task of joining the violin plates from the bookmatched back and belly sets. First I squared up the beautiful maple blanks and planed the two edges together to ensure a good fit.  This was so much easier to do compared with the cello as the pieces of wood are so much smaller/lighter and the join quite short.  I heated the pieces gently with the air gun and then glued them together with a rubbed joint which worked really well first time.

Next I planed the underside surface flat before tracing the outline from the ribs and using a washer to give the external dimension including 2.5mm overhang.

I cut out both belly and backs on the bandsaw leaving a bit of waste to be cleaned up after shaping the outside profile.

This was so quick I ran the same process for the belly.

Carving the outside profile

Next I created a set of templates for both back and belly based on the profile curves published by Sergei Muratov (the same source I used for the cellos).  I drew these up in solvespace and then stuck the full size printed drawings to a piece of perspex, cut out on the band saw and then finished on the vertical oscillating sander.  I finished by spraying these with a bright paint – different colours for front and back so they didn’t get mixed up.

Then to carving starting with a 3/4″ no 5 sweep chisel to get the rough shape. 

I cut a 10 mm wide platform at the edge with  the router using the same attachment I made for the cello work.  

These were cut at the finished edge thicknesses of 3.7 mm (back) and 4 mm (belly) and make it much easier to start the gouge cuts. 

Then I moved onto using thumb planes.

Here I am getting pretty close to the final profile.

I tack assembled the back and belly to the sides to cut the side overhangs down to final size – 2.75mm except for the c-bouts at 3mm. Started with the knife and finished with files with a piece of waste of the correct thickness taped to the middle of the file.

Also cut the corner shapes with a knife.

Purfling

Next job is to cut the purfling groove so I made up a simple holding jig for the body first.

Then I made up a laminate 1.4mm thick for the purfling of 0.3mm black (ebonised pear), 0.8mm white (sycamore) and another 0.3mm black. I sliced this up on the bandsaw into strips about 2.5mm wide.

Then I marked the purfling groove on the front and back with special gauge set in 4mm from the edge and deepened these faint marks with a scalpel lubricated with dry soap and carefully carved out the groove with a 1mm chisel.

Next I carefully fitted the purfling using the bending iron taking special care with the corners and glued up with hot glue.

Then trimmed back with a chisel when dry and gouged the channel round the edge about 1mm deep before fairing everything in with scrapers and checking the final arching.

There is a slight blemish in the maple on the back. I was hoping I would get through it with arching but there is a tiny thin bit left and I would rather keep the proper arching than keep on scraping away –  it looks like bark but it can’t be as it was not visible before carving.  Should dissappear when the back is coloured anyway.

Thicknessing

I started by marking out the thickness profile contours and then drilled on the bench press to a few millimeters thicker than this to make the rough thicknessing quick and safe.

Then I roughed out with a large gouge.

Now I have to build a caliper/nail tool for marking the finished thickness before plate tuning.

And it works really well – I have made it big enough so I can do a cello with it.

Nearly down to the initial thicknesses before plate tuning.

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Preparing the blocks

I split some willow to make the blocks and set them at 32mm high at the bottom tapering to 30mm high at the neck and after getting them good and square, glued them into the form which I supported on a few pieces of plywood to get the form more or less into the centre of the blocks.

Then I used the perspex template to mark the outline on the blocks ready for carving.

When the glue was dry I carved the blocks down to the marked outline with a chisel and finished with a round file. The split willow carves very easily but because they are so small this is so much quicker to do on the violin compared to the cello – although you have to go slowly to get the accuracy required!

Preparing and fitting the violin ribs

Next I thinned the ribs down to 1mm with a combination of the drum sander and then scrapers. The figuring has to be matched up so the stripes all point upwards when looking at the back. Next the pieces were cut to size and carefully bent after damping in a wet tea towel and then finally glued to the blocks using pre-shaped cauls.

Then I planed the edges of the ribs down to make sure everything was perfectly flat.

Adding the Linings

I thinned the willow linings to 2.1 mm on the drum sander and cut them 10 mm wide on the band saw (aiming for 8 mm finished depth) to leave a few mm proud for trimming back flush to the ribs.

I was able to re-use the peg clamps I made for the cello and just substituted a thinner pivot piece to get a parallel clamp on the 1 mm ribs + 2.1 mm linings.

Now to move onto the back where I have some gorgeous maple to play with!

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