Tag Archives: 2017

Cello build #3

Having just retired I recently started my 3rd cello build.  I think this is going to be a real pleasure as I no longer need to burn the candle at both ends to find time for the luthiery.

The mold

I started by building a new mold that I can leave in place whlle rough fitting the back and belly to enable the overhang on the edges to be set really accurately. It is designed so that it can be taken out easily after the linings have been fitted.

Inner part of new cello mold
New cello mold bolted up

The ribs

I cut blocks from willow for the corners and spruce for the ends and glued into the mold before shaping with chisels and files.

Blocks glued into mold
Blocks carved to shape

Then I scraped the ribs and sanded down to 1.4mm on the drum sander before cutting to size, bending and glueing to the blocks.

Gluing in the c-bout ribs

Then I could remove the outer parts of the mold to fit the linings which I mitred into the corner blocks.

Top section of mold removed to allow fitting of linings
Linings fitted

The plates

I had some lovely pieces of book-matched spruce and maple from David Dyke which I cleaned up and carefully planed the edge square and true.  This takes a lot of time (for me) to ensure an absolutely perfect fit ready for the rubbed joints.  Once dry I then flattened the back surface with the jack plane.

Book-matched back planed flat

Then I used the rib assembly to mark out the outline on each plate allowing 3mm of overhang (using a pencil and washer) before cutting out on the bandsaw.  (Post build note – should be more like 4.5mm).

Then onto the lengthy process of carving the outside profile of the plates.

Rough shaping of the back with a chisel
Top after starting to rout shelf all round the edge
Back after starting to rout shelf all round the edge

Once the plates outer profile had been carved to match the templates I assembled the plates onto the ribs (with the form still in place) and then used a file with a 3mm wood off-cut attached to file the overhangs to an exact 3mm all round and also set the final rib thicknesses (5.2mm on the back and 5.6mm on the belly).

Plates temporarily assembled onto ribs and overhang set ready to do purfling

Then I marked the purfling channels set in 5mm from the edge and cut out using a scalpel and a fine chisel.

Purfling glued in on back plate
Purfling channel cut and faired in to back profile

Next I dismantled the back and front plates from the rib assembly ready to carve out the inside profiles. 

To make this quicker I first drilled holes to a depth a few mm shy of the finished thicknesses.

Back plate drilled to give rough thicknesses

Then a lot of elbow grease with first gouges and then thumb planes to get to the starting profile where I start exciting the plates with a loudspeaker coupled to a variable frequency oscillator.

It turned out that the spruce for top had a very low transversal thickness making it very difficult to maintain the x-mode frequency.  I ended up having to fix a patch using some wood from a good stiff guitar top to bolster the transversal stiffness and even after that I had to accept an x-mode frequency more than an octave below the ring mode. This meant trying to keep the back’s ring mode about a semitone higher.

Final tuning was done after cutting the f-holes and fitting the bass bar to the top.

Gluing on the bass bar

I ended up with the following mode frequencies and plate weights:

  Mode 1 Mode 2 (x-mode) Mode 5 (ring mode) Weight
Top 26.5Hz 52.6Hz 119Hz  (A3 +36cents 488g
Back 31.2Hz 63.2Hz 127.5Hz (B3 +55cents) 785g

Assembling the box

I started by roughly trimming the ends of the blocks before gluing the back on carefully. This was much easier with the rib form still in place.

Gluing on the back

Then I removed the collapsible rib form, finished shaping the blocks and drilled the pilot hole for the endpin.

Corner and end blocks shaped and inside cleaned up ready to glue on top plate

Finally I glued on the top plate which fitted pretty well.

The neck & fingerboard

Firstly I planed and scraped the fingerboard blank to size and set the string relief to half the diameter of the strings.

For the neck, I started by squaring up the maple blank and carefully marking the outline in pencil. I had previously made a template from perspex to make this easier – particularly for the scroll where I marked through guide holes with a pin.

Squared up maple neck block marked up ready for cutting on bandsaw

Then I used the bandsaw to cut out the outline shape and a handsaw to cut down the neck which I then trued up with rasps and files.

Cleaning up the rough outline of the neck

While the scroll was still a square block I drilled the pilot holes for the pegs and then cut the scroll-box cheeks with the bandsaw.

Cutting the cheeks on the bandsaw

Then I sawed the scroll profile a segment at a time before using gouges and scrapers to reach the finished shape.

Sawing the scroll outline
Scroll nearly done


Assembling the box

Before shaping the heel I temporarily glued on the fingerboard and fitted the neck joint using chalk and going slowly so that I achieved:

  • A fingerboard projection at the bridge of 83mm
  • An up-stand of 23mm
  • A neck stop of 280mm

This is probably the trickiest bit and absolutely key to playability so worth spending the time to get it right.

Having fitted the neck joint I than shaped the heel and neck with rasps, files and sandpaper before gluing up the neck joint.

Getting ready to glue on the neck
Neck glued on

Then I trimmed up the heel, cleaned up any surplus glue and sanded down the whole instrument with 600 grade emery paper. Then I wetted the whole instrument to raise the grain and sanded again ready for finishing.

Cleaned up and ready to go in the fuming cabinet


I started by darkening the instrument with a few days in the fume cupboard with a bowl of ammonia and then sealed with a few coats of shellac, rubbed down with 600 grade and then a final shellac coat.

After sealing with 2 coats of shellac
After sealing with 2 coats of shellac

Then I mixed some artist paints (2 parts burnt sienna, 1 part burnt umber and 1 part alizarin crimson) with a few drops of linseed oil and rubbed in evenly with a rag.

After 1st application of artist colours
After 1st application of artist colours

Following drying in the UV cabinet the colour was way too light so I repeated the exercise and then gave it its first coat of colour varnish. The back is looking particularly pleasing.

After 1st coat of colour varnish
After 1st coat of colour varnish









The colour is still a bit on the light side so I gave it another coat of artists colours with more burnt umber and less red and then another coat of varnish.

After more artist colour and another coat of varnish
After some more artists colours and another coat of varnish

Then I left it in the UV cabinet for 2 weeks before cutting back, polishing and finishing with a wiped on coat of linseed oil.

Then I re-fitted the fingerboard and finished the neck with a couple of thin coats of linseed oil and burnt sienna artists colours burnished to a good shine.

Gluing fingerboard back on cello #3

Then I shaped and fitted the saddle, nut and bridge before stringing up with a set of larsens.

Finished Instrument

The finished instrument weighs in at 2940g, sounds wonderful

With Larsens

With C/G Spirocores

and looks like this:

Cello #3 front view
Cello #3 back view


Cello #3 side view
Cello #3 ff holes
Cello #3 peg pox
Cello # 3 scroll

Violin week 8 – Setup

Now the instrument is basically finished it is time to set it up and hear how it sounds.

Fitting the Violin pegs

Having already shaved down the pegs to match the taper on my peg-hole reamer, I smoothed them with 600 grade emery paper and gave a light wipe-on coat of finishing oil and then burnished with wire wool.

The peg-holes were then reamed out carefully so the distance from the peg-box to thumb-piece was 16 mm. In order hold the pegs I built a simple jig to hold them while they were drilled with a 1.3 mm bit for the string holes and then lightly chamfered the edges of the holes. 

Simple jig to hold peg while drilling the string hole

The outside of the peg was marked where it protruded from the peg box and I carefully sawed off the excess using the same jig to hold the peg. Finally I rounded the end with files and 600 grade emery paper.

Fitting the Violin Nut

The Evah Pirazzi medium gauge violin strings I am fitting have diameters of 0.8, 0.66, 0.66, 0.21 mm

So to have string height above fingerboard of 0.5, 0.45, 0.4, 0.35 mm and slots 1/3 of diameter of string the nut height should be:

0.76, 0.67, 0.62, 0.42 mm

I marked the ebony nut against the end of the fingerboard and then filed down to give a 1 mm step and faired in nicely to the sides and entry to the peg-box.  Once smoothed with 600 grade and wire wool the nut was lightly glued to the end of the fingerboard.  I adjusted the step from 0.8 to 0.5 mm before marking the string positions using a sharp knife. I set the strings with 5.5 mm between centres and the E string 8 mm from the centre line.  This gives slightly more room for the E string than the G . The knife marks were then widened first with a triangular file and then with nut files.

The last step was to file the top of the nut down so that the slots only held 1/3 string and then finished with emery paper and wire wool.

Fitting the Violin Bridge

Starting with an Aubert Miracourt blank I followed the fitting guidelines in this very good article on how to fit a bridge by Lars Kismer. I built a simple jig to hold the bridge perpendicular to the top.

Simple jig to hold the bridge

Fingerboard projections were marked on the bridge and action marked at 2.5 mm on the E string up to 5 mm on the G string and joined with a curve of 41 mm radius.  I purchased a banjo head made of goat’s skin on e-bay which provides perfect parchment material for reinforcing the E-String notch. 

Setting the After String Length (ASL)

The violin tailpiece gut was adjusted to make the ASL approx 1/6 of the string length and then fine-tuned so that the after string tuning on the G string was an octave and a fifth below the D string.

Side view

The finished violin (without chin-rest) weighs in at 420 g.

Fitting the Violin chin-rest

I settled on a Kreddle chinrest as the client specifically wanted something high.  The Kreddle provides plenty of adjustment flexibility in this regard and came highly recommended. I also found it extremely easy to fit and adjust.

On first play of the finished violin, the G and D strings have a lovely rich sound and the E is strong and sweet but the A ran out of steam a bit at F.  Opening up the heart on the bridge a little and tuning the B0 resonance to the A0 body resonance by putting a small piece of Plasticine under the end of the fingerboard made a big improvement.

Delivered to my client yesterday at Orchestra who was delighted with it – brilliant timing too as we had the fabulous violinist Sarah Sew working with us on the Elgar violin concerto and she was kind enough to give it a workout. Her verdict : ” it works – I mean it really works and powerful too”. Sarah also said it compared very favourably to many new build professional instruments (she tries out a lot of them) but found it a little on the  “chunky” side compared to her wonderful Italian Gagliano – so not really a surprise as that is actually quite a small instrument.  Clearly I will have to work on making my next violin a bit “finer”.


Violin Making Tools & Jigs

This gallery shows some of the jigs I have made for building violins.

  • Violin peg shaver

Violin week 7 – Finishing

At last I have reached the fun bit where the beauty of the wood finally comes to light.

Cleaning up

The first step was to clean up the instrument all over using a scraper a 600 grade emery paper to get rid of any remaining tool marks and surface blemishes.

Then the fingerboard was easily popped off and replaced with a guard piece held on with a weak glue solution to make access to the top while varnishing much easier.

Giving it a Sun Tan

Then into the UV cabinet for a few weeks to start the ageing process and give the wood a natural darkness and bring out the figure on the maple.

I put a bowl of water in the cabinet to stop things getting too dry.

Into the lightbox for a few weeks

Peg Shaver

While it was getting a tan a made a simple peg shaver to deal with tiny (compared with the cello) violin pegs.

I just squared up a piece of maple thick enough to tak a peg hole and wide enough to take the full peg length. I then drilled and reamed a peg hole  to fit the peg blanks and then cut a quadrant out so i had a surface to mount the blade.  Previous shapers I have built had the blade mounted near the top of the peg a bit like a pencil sharpener but I found these tended to grab the grain.  So on this shaver I took a blad from a cheap chinese scraper and mounted it more like a scraper halfway down the side of the peg secured with a few 5mm set screws and then fitted a few fine adjusting screws through a side block.

Violin peg shaver

Seems to work really well.


This is what it looks like after 1 week in the cabinet

Front after 1 week in UV cabinet
Back after 1 week in UV cabinet

After 2 weeks I made up some ground coat the same as for the cello and rubbed in with a rag, Once dry I sanded back with 600 grade emery paper to make it flat and gave it 2 coats of wiped on shellac sanding back between coats.

Back after ground coat
Top after ground coat

I had to repeat the process after flattening with 600 grad a few times before adding the colour glaze. I made this up from golden brown varnish, linseed oil and artist colours (burnt sienna and a little alizarin red). Rubbed a couple of thin coats of this in with a cloth and this what it looks like.

Front after colour glaze
Back after colour glaze

Next for a coat of golden brown varnish before I decide whether or not to do any more colour adjustments.

After 1st colour coat
Back after 1st colour coat

Still needs more colour so another colour glaze going on next.

After another colour glaze and colour coat

The maple back is looking much better now with the flame really shining through. Once I have finished the varnish coats and cut it back the glossy shine should change to a much more pleasing satiny finish.




After another colour glaze and colour coat

















I think the front still needs a bit more richness before the next colour coat so colour glaze again.

After final colour glaze

So now for one more colour coat and a few clear coats.

Last clear coat finished
Last clear coat finished

Clear coats went on very easily making sure I sanded very lightly between coats to get rid of any surface dust and hairs.

The violin has a lovey glow and colour has been kept light as this client wanted.

Now into the light box for a couple of weeks to dry /harden the varnish properly before cutting back, polishing and then fitting the fingerboard and finishing the back of the neck.

After cutting back with progressively finer emery cloth down to 4000 grade I used rotten stone and linseed oil to finish.

Then I re-glued the neck after re-flattening the fingerboard and neck which had both moved very sightly.

Gluing the neck back on
Finished awaiting setup
Finished awaiting setup
Finished awaiting setup



Violin week 6 – The neck

Shaping the neck blank

First I squared up the neck block and then marked the outline and scroll detail from the template I had made out of perspex and rough cut the outline on the bandsaw.  Then I drilled the pilot holes for the pegs taking care to angle each hole slightly so that the pegs would be drawn into the box by the string tension.

Then I used gouges and files to get the correct outline before marking the details of the fingerboard, pegbox and scroll.

Neck rough cut from blank on the bandsaw and pilot holed drilled for pegs
Outline marked in pencil and first cuts done

Then I carefully sawed out the scroll a section at a time and then used gouges to get close to the finished shape.

Scroll roughly cut with chisels

I used scrapers and files to get to the finished shape.

I started the pegbox by sawing the sides and then used a sharp knife to continue deepening the sides and hogged out carefully with a chisel aiming at a bottom thickness of 5mm.

Then I used a gouge and scrapers to carve out the fluting on the back and scroll.

Scroll nearly done
Scroll nearly done


I had a nice clean ebony blank for the fingerboard and easily flattened the back and planed to the correct width profile.

I made a simple profile template out of a piece of rib set to 42mm radius and used this to guide the shaping of the fingerboard aiming at side heights of 5.5mm.  There was a lot of material to remove and when I got close I moved to scrapers.  Finally I scraped out the fingerboard relief at about 0.5mm on the treble and 0.75mm on the bass.

Fingerboard ready to be tacked onto neck

I used a few small spots of weak glue to tack the fingerboard to the neck and set about cutting the neck joint.

Neck joint

First I planed the root of the neck to size and then carefully transferred the width measurements to the ribs and used a scalpel to cut the ribs making sure I cut the slut slightly narrow.

I marked the position on the side of the neck where it should intersect the top of the belly plate giving a standoff of 6.4mm and a distance to the nut of 130mm and then marked the top of the mortice on the belly and cut down with a scalpel before using a chisel to carefully deepen the slot.

It is a very iterative process gradually deepening and widening the slot, planing the heel to fit and checking for the fingerboard projection at the bridge of 27mm.

After several hours I got it all to fit perfectly so it would just hold dry fitted.

Neck joint dry fitted
Gluing the neck

After letting the glue dry I started to shape the button and neck with chisels and then files. My aim was to get the total depth of neck + fingerboard at the nut to be 18.5mm and  20.5mm near the heel.

Neck rough shaped

Now for a final clean up and into the light box for a few weeks.

Into the lightbox for a few weeks

It looks as if the instrument is going to weigh in at about 415g once finished with all its fittings.