Category Archives: Stringed Instrument Making

Completed Viola #2

This is a repeat of a first very successful commissioned instrument. It is small with a body length of only 390mm (15.4″) that is based on an 1830 Guadagnini and the record of that first build can be found here.

I visited Steffen Nowak again in Bristol to select the wood.  His selection was a little limited due to Covid but still had some lovely figured sets to choose from.  What I ended up with choosing was some well seasoned Bosnian maple from 2011 for the back sides and neck and some Alpine spruce from 1992 for the front.

I am keeping the design the same and the build process for #2 is recorded below:

  • Wood from Steffen Nowak. 30 year old spruce and 12 year old maple.
    Wood from Steffen Nowak. 30 year old spruce and 12 year old maple.
  • Neck blank rough cut out to give it a chance to settle before final shaping.
    Neck blank rough cut out to give it a chance to settle before final shaping.
  • Spruce blank sawn through
    Spruce blank sawn through
  • rib blanks
    rib blanks
  • Ribs thicknessed to 1.1mm
    Ribs thicknessed to 1.1mm
  • Maple back blank resawn before bookmatch jointing
    Maple back blank resawn before bookmatch jointing
  • Rubbed joint on back
    Rubbed joint on back
  • Ready to glue in the willow blocks
    Ready to glue in the willow blocks
  • Spruce front rubbed joint
    Spruce front rubbed joint
  • Willow blocks glued into the form
    Willow blocks glued into the form
  • Blocks marked for carving
    Blocks marked for carving
  • Blocks carved ready to take ribs
    Blocks carved ready to take ribs
  • Inside of the back flattened
    Inside of the back flattened
  • Front flattened
    Front flattened
  • Front rough thicknessed to 18mm
    Front rough thicknessed to 18mm
  • Back rough thicknessed to 16.5mm
    Back rough thicknessed to 16.5mm
  • Ribs cut to length and grain patterns oriented
    Ribs cut to length and grain patterns oriented
  • Glueing in the C bout ribs
    Glueing in the C bout ribs
  • Gluing in the lower bout ribs
    Gluing in the lower bout ribs
  • Gluing on the remaining ribs
    Gluing on the remaining ribs
  • Marking out the back profile around the ribs using a washer to give the 2.8mm overhang.
    Marking out the back profile around the ribs using a washer to give the 2.8mm overhang.
  • Back marked up ready to cut out on the bandsaw
    Back marked up ready to cut out on the bandsaw
  • Front profile marked ready for cutting out
    Front profile marked ready for cutting out
  • Gluing in C-bout linings on the back
    Gluing in C-bout linings on the back
  • Linings fitted to back and levelled off flush with top of ribs.
    Linings fitted to back and levelled off flush with top of ribs.
  • Back cutout on bandsaw
    Back cutout on bandsaw
  • Front cutout on bandsaw
    Front cutout on bandsaw
  • Rough carving the back with chisels
    Rough carving the back with chisels
  • Carving the back using thumb plane
    Carving the back using thumb plane
  • It's a long process and the maple is really hard!
    It’s a long process and the maple is really hard!
  • Back profile finally finished after days of chiselling, planing and scraping
    Back profile finally finished after days of chiselling, planing and scraping
  • Started to chisel out belly outside profile - so much easier than the maple on the back
    Started to chisel out belly outside profile – so much easier than the maple on the back
  • Nearly finished with thumb planes on the outside profile - scrapers next
    Nearly finished with thumb planes on the outside profile – scrapers next
  • Temporarily tacking the back and belly to ribs in order to set the edge overhang before marking and cutting purfling grooves.
    Temporarily tacking the back and belly to ribs in order to set the edge overhang before marking and cutting purfling grooves.
  • Standoffs taped to file for finishing the edge overhang
    Standoffs taped to file for finishing the edge overhang
  • Edges all trued up ready for marking purfling slots
    Edges all trued up ready for marking purfling slots
  • Veneer cut ready for gluing up the purfling sandwich
    Veneer cut ready for gluing up the purfling sandwich
  • Gluing the purfling sandwich
    Gluing the purfling sandwich
  • Started purfling slots
    Started purfling slots
  • Purfling slots cut on the top
    Purfling slots cut on the top
  • Purfling sliced up on bandsaw
    Purfling sliced up on bandsaw
  • Purfling slots cut on the back
    Purfling slots cut on the back
  • Purfling dry fitted to back
    Purfling dry fitted to back
  • Purfling levelled off on back before cutting the purflng channel
    Purfling levelled off on back before cutting the purflng channel
  • Finished cutting and fairing in the channels on the back
    Finished cutting and fairing in the channels on the back
  • Finished cutting and fairing in the channels on the top
    Finished cutting and fairing in the channels on the top
  • Carving out the back with gouges
    Carving out the back with gouges
  • Carving out the inside of the back with thumb planes
    Carving out the inside of the back with thumb planes
  • Mode 5 309hz - early stage in plate tuning process
    Mode 5 309hz – early stage in plate tuning process
  • Mode 2 - early stage in plate tuning process
    Mode 2 – early stage in plate tuning process
  • Roughing out inside of top with gouges and thumb planes
    Roughing out inside of top with gouges and thumb planes
  • Mode 2 @ 130.8Hz on belly
    Mode 2 @ 130.8Hz on belly
  • Mode 5 @ 260.9Hz on belly
    Mode 5 @ 260.9Hz on belly
  • Final contours on back
    Final contours on back
  • Mode 2 @ 126.8Hz on back
    Mode 2 @ 126.8Hz on back
  • Mode 5 @ 263.2Hz on back
    Mode 5 @ 263.2Hz on back
  • Marking out f holes
    Marking out f holes
  • f holes cut
    f holes cut
  • Gluing in bass bar after chalk fitting
    Gluing in bass bar after chalk fitting
  • Initial mode 2 @ 133Hz after fitting bass bar
    Initial mode 2 @ 133Hz after fitting bass bar
  • Initial mode 5 @ 282 after fitting bass bar
    Initial mode 5 @ 282 after fitting bass bar
  • Mode 2 @ 127.1Hz on back
    Mode 2 @ 127.1Hz on back
  • Mode 5 @ 262Hz on back
    Mode 5 @ 262Hz on back
  • Mode 5 @ 255.9Hz on belly after bass bar tuned
    Mode 5 @ 255.9Hz on belly after bass bar tuned
  • Mode 2 @ 127.8Hz on belly after bass bar tuned
    Mode 2 @ 127.8Hz on belly after bass bar tuned
  • Blocks carved back ready for glueing on the back
    Blocks carved back ready for glueing on the back
  • Gluing on the back
    Gluing on the back
  • Adding the linings on the front after removing the form
    Adding the linings on the front after removing the form
  • Measuring mode 5 frequency (dropped to 227Hz) on the attached back
    Measuring mode 5 frequency (dropped to 227Hz) on the attached back
  • Blocks carved back and cleaned up ready to glue on the top
    Blocks carved back and cleaned up ready to glue on the top
  • Gluing on the top
    Gluing on the top
  • Box closed up
    Box closed up
  • Neck blank trued up and marked up ready for carving.
    Neck blank trued up and marked up ready for carving.
  • Just needto add flutings now
    Just needto add flutings now
  • The finished scroll
    The finished scroll
  • Fingerboard shaped
    Fingerboard shaped
  • neck joint cut
    neck joint cut
  • Finished neck and fingerboard ready to glue onto body.
    Finished neck and fingerboard ready to glue onto body.
  • Gluing on the neck
    Gluing on the neck
  • After a couple of coats of Vernice bianca
    After a couple of coats of Vernice bianca
  • Finished instrument after 2 coats of Vernice Bianca, 1 coat of shellac and 10 coats of oil varnish.
    Finished instrument after 2 coats of Vernice Bianca, 1 coat of shellac and 10 coats of oil varnish.

Here are some pictures of the finished instrument which weighs in at 522g (without chinrest):

Viola #2 front
Viola #2 back
Viola #2 side view

Making Cello No.4

Design

I decided to have a go at another cello because I enjoy building them so much!  Of course I also wanted to improve on the cellos built so far by making a few judicious design changes and tweaking the build process based on experience with the earlier builds.

The key design changes were:

  • Sight changes to the archings (25mm belly and 23mm back)
  • Reduce f/b side thickness to 7.5mm from 8mm
  • Change break angles over the strings to improve playability (19.5 degrees ADG and 24 degrees DGC)
  • Changed f/b profile to match change in bridge profile
  • Increase over-stand by a few mm to 22mm
  • Attempt to increase Mode2 and Mode 5 plate frequencies to around 65Hz and 130Hz
  • Colouring the instrument a richer chestnut brown 

The resultant design drawings done using solvespace are below.

cello template da2 top

cello #4 back profile

cello #4 belly profile

fingerboard profile #4

cello #4 side view

cello #4 neck

I also decided to make use of my CNC router to build new 6mm MDF templates based on these drawings.

Build process

As usual, not everything went perfectly to plan but most of the desired changes seemed to work.  The one area I had real difficulty with this time was tuning the plates especially as i was trying to hit higher resonant frequencies this time around.  As I was trying to tune the top I was having real difficulty getting mode 2 and 5 and octave apart – the ring mode just didn’t want to drop.  Then I happened to wash the outside of the top to get rid of some surface bruising (from when the top was drilled out) and the following morning it suddenly started to behave properly!  My assumption is there must have been some latent stresses in the spruce and the wetting allowed them to settle out – a bit like annealing.  Anyway I ended up with Mode 2 and 5 exactly an octave apart and matching on back and top at 60Hz and 120Hz respectively.

The finished instrument is a beautiful chestnut colour and has wonderful a rich singing tone using a set of Larsen Magnacores.  I have christened her “Doris” and she weighs in at 3.01kg.

I am delighted with her – a definite keeper!

The finished instrument

The following gallery illustrates the build process.

New Workshop Completed

I finished building my new workshop a few weeks ago – something I decided to start building to get me out of my super-cramped garage as soon as the Covid-19 lockdown was announced back in March.

I went for a simple wooden framed design on a concrete base with a flat roof to give me as much headroom as possible whilst staying within the 2.5m permitted development limits on height.  Plenty of rockwool insulation in the walls and ceiling and a few inches of celotex on the floor should keep things toastie in winter as well as keeping the machine tool noise inside.  I clad it in Siberian larch feather-board for a good and long lasting look.

I now finally have room to swing a cat while making musical instruments (or anything else) although there is still quite a lot of stuff still left in the garage!  Here are some pictures of the finished workshop:

And here is a gallery showing the construction process over the last 3 months:

 

Viola “Carice” finished

After 6 months of work my first viola is now finished and my client has decided to call her “Carice” after Elgar’s daughter.

It is copy of a 15.4″ Guadagnini and weighs in at just 512g (without the chinrest) 575g with a Kreddle chinrest compared with 565g for the original. 

Sounds rich and responsive (when I play it like a cello!).

See the build history here.

Finished viola body

Finished viola back

Finished viola front

 

 

 

Finished viola peg box

Finished viola side

Finished viola side

Viola build

So I have just started with my new viola build based on a late Guadagnini from about 1830.  This is a small instrument with a body length of only 390mm (15.4″) but it is remarkably resonant and a joy to play.

Design

I started by measuring up the Guadagnini in great detail and then transferred those measurements to a set of drawings done using the solvespace parametric drawing package.

The resultant drawings are here as pdfs:

guad top mold

viola guad side profile

viola guad neck

viola guad ff holes

I procured some nice looking spruce and maple from Steffen Nowak in Bristol.

Split spruce and nicely figured maple for the viola

Making the templates

Next I embarked on making the templates by transferring the drawings onto polystyrene sheet and then cutting out on the bandsaw.

The arching and neck templates

And built the body form from 10mm plywood.

The polystyrene body template and form made from 10mm ply

I used the neck template to roughly cut out the neck blank to give it a chance to move while I built the rest of the instrument.

Neck blank roughly cut out

I also did the rubbed joints on the back and belly after sawing the blanks on the bandsaw to give me bookmatched sets.

Bookmatched sets after doing the rubbed joint

which I then planed flat.

Back planed flat

Belly planed flat

and thicknessed on the drum sander about 1mm more than the desired arching.

The ribs

I carefully made block blanks by splitting spruce for the end blocks and willow for the corner blocks, cut to the correct height and glued into the form.

Then I shaped them using gouges and finished with japanese files.

Blocks shaped ready for ribs

Then I carefully prepared the ribs using the drum sander and scrapers to get them to 1.1mm thickness, cut them a few mm oversize on the bandsaw and then bent them on the bending iron before gluing onto the blocks with pre-made cauls.

After roughly levelling the edges with a plane I made them absolutely flat and true  by rubbing the rib assembly against a sheet of sandpaper on a flat surface. Then I cut the linings from some willow at 2.1mm thick and sightly oversize at 10mm deep and fitted them to the ribs.

Linings added

Belly and back

First I marked the outline of the back and belly using the ribs and a washer to give the 2.8mm overhang. These were then cut out on the bandsaw before using a router with a homemade attachment to cut a shelf around the edges where the purfling would go. Then I used gouges, thumb planes and finally scrapers to set the arching shape against the already made templates.

Rough shaping of the arching on the back

Back arching (outside) complete

Front arching (outside) complete

The next task is to glue up the box temporarily and file the edge overhang. I decided to use pins this time to make the assembly and re-assembly easier so I selected some small panel pins about 1.4mm dia and after clamping top and back together on the mold when all trued up,  I drilled small 1.4mm holes on the pillar drill about 6mm in from the edge. The plan is to then drill out the holes on the back and front to 2mm after final assembly and fill with small wooden plugs. With a bit of luck these will be hidden by the purfling on the back and covered by the neck joint and saddle on the front.  I snipped the heads off the panel pins before pushing into the holes on the top and bottom blocks and then tacked it all together with weak animal glue – worked really well.

Box glued up temporarily ready for filing the edge overhang

I cut a small offcut to 2.8mm thick and a bit shorter than the depth of the ribs and fixed to a file with some masking tape. This is a great way to get the edge overhang constant but I used a knife on the corners to get them looking even.

Edges filed to 2.8mm and corners rough shaped

Next I marked the purfling channels. I used a new toy – a marking gauge by Veritas that uses a circular cutter – very effective at resisting grain following but can only use on the outside curves. I think I may make an adapter with some brass tube so that I can use on inside curves too.

New marking gauge

With simple attachment for managing inside curves

Then I used a scalpel to deepen the marks and chipped out with a 1mm chisel.

Purfling grooves cut on the top

Purfling channels cut on the back

Finally I bent and fitted some purfling I had left over from the last violin.

Purfling glued in on the belly

Purfling glued in on back

The next job is to cut the purfling back and then cut the channel with gouges and fair into the body with scrapers.

Purfling channels cut and faired in on belly

Purfling channels cut and faired in on back

Next I separated the plates from the body ready for thicknessing the plates.

I started with the back, using the pillar drill to give me holes at roughly the right thickness and then used gouges and thumb planes to bring in the correct profile checking the mode shapes and frequencies regularly.

Back marked for initial thicknessing

Back drilled for initial thicknessing

I am aiming at 125Hz for mode 2 (x mode) and 250Hx for mode 5 (ring mode). I left them a bit higher on the back at this stage until I have finished the front.

Tuning x-mode on the back

Tuning ring mode on the back

Then I repeated the process on the front finishing up with scrapers. Much easier on the top with the soft spruce.

Top marked for initial thicknessing

X-mode on the front tuned to 125Hz

Ring mode on front tuned to 250Hz

The top plate is nice and light too at only 74 g so hopefully it will be responsive.

Next job is to cut the ff holes. I marked the ff-hole outline by pricking through a scale drawing with a pin and carefully drilled the holes undersize before opening out to designed dimensions with a reamer.  Then I used a fine toothed coping saw to rough cut the outlines before opening out with a scalpel and cutting the nicks.

ff-holes roughly cut

ff-holes after carving out with a scalpel

Then I marked the position of the bass bar and cut and drum-sanded the piece I had initially sawn from the top blank to make the bass bar 6mm wide. This was then chalk fitted to the top, glued in and roughly planed to profile before tuning.

Gluing in the bass bar

I discovered that the x-mode had increased from 125 to 127 Hz but the ring mode had gone from 250 to 280 Hz so I was going to have to be careful to maintain the x-mode frequency.

After a lot of patient adjustment on both bass bar and top plate, I managed to get the the two modes back to the target 125 Hz and 250 Hz.

x-mode on the top @125Hz after tuning the bass bar

Ring mode on the top @250Hz after tuning bass bar

The bass bar ended up being quite low at about 10 mm in the middle and 4 mm at the ends.

Next I tuned the back to match which weighed in at 130 g.  I am extremely pleased with how well I have got the two plates to match with the x-mode and ring modes also being perfect octaves apart.

X-mode on the back @125Hz

Ring mode on the back @250Hz

Then I took the rib assembly and roughly carved the exposed blocks on the back to shape before gluing up using the locating pins in the end blocks.

Gluing on the back

Once the glue was dry I removed the mold ready to fit the linings for the top.  AFter fitting the linings I carved down the blocks, generally cleaned up and fitted the label ready for gluing on the top.

Cleaned up inside ready for gluing on the top

I used the pins again to locate the top when gluing  which I then removed and plugged the holes with small wooden dowels I made up from matching wood.

Assembling the box

Finally I rounded the outside edges with files and then 600 grade emery paper.

The next job is to make the neck.

Finished box ready for fitting the neck

The neck

I started by truing up the neck blank that I had roughly cut out out at the start of the build as it had moved a bit (as expected).

After truing it up and then filing to match the template outline, I drilled the peg holes with a 6mm drill at a slight angle to help the string tension hold them in place.  Then I marked the scroll outline before sawing the scroll a segment at a time.

Shaped neck blank marked up before cutting scroll

Sawing the scroll

After a lot of sawing, gouging, filing and sanding the scroll started looking about right.

Scroll well on the way

I then used gouges and sandpaper to cut the flutings before cutting the pegbox by sawing down the sides and then chiselling out.

Pegbox chiselled out after carving the flutings

Finally I cut the neck root at a slight angle to give me 1mm higher overstand on the C string side before starting the tricky process of cutting and fitting the neck joint. Before I could do that I needed to  cut the fingerboard to size and carefully shape the profile longitudinally to give the correct relief and transversely to get the correct action and make it easy to play.  Then I tacked the fingerboard to the neck with a few spots of weak glue ready for cutting the neck joint.

Fingerboard ready for yacking onto neck

Tacking the fingerboard onto the neck

Fitting the neck joint took the best part of a day ensuring I maintained a whole set of key dimensions:

  • Nut to top plate distance
  • Fingerboard overstand
  • Fingerboard projected height at the bridge
  • Fingerboard central over top plate

while ensuring a perfectly fitted joint.  I got there in the end and it held together perfectly dry.