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.
Neck blank rough cut out to give it a chance to settle before final shaping.
Spruce blank sawn through
rib blanks
Ribs thicknessed to 1.1mm
Maple back blank resawn before bookmatch jointing
Rubbed joint on back
Ready to glue in the willow blocks
Spruce front rubbed joint
Willow blocks glued into the form
Blocks marked for carving
Blocks carved ready to take ribs
Inside of the back flattened
Front flattened
Front rough thicknessed to 18mm
Back rough thicknessed to 16.5mm
Ribs cut to length and grain patterns oriented
Glueing in the C bout ribs
Gluing in the lower bout ribs
Gluing on the remaining ribs
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
Front profile marked ready for cutting out
Gluing in C-bout linings on the back
Linings fitted to back and levelled off flush with top of ribs.
Back cutout on bandsaw
Front cutout on bandsaw
Rough carving the back with chisels
Carving the back using thumb plane
It’s a long process and the maple is really hard!
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
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.
Standoffs taped to file for finishing the edge overhang
Edges all trued up ready for marking purfling slots
Veneer cut ready for gluing up the purfling sandwich
Gluing the purfling sandwich
Started purfling slots
Purfling slots cut on the top
Purfling sliced up on bandsaw
Purfling slots cut on the back
Purfling dry fitted to back
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 top
Carving out the back with gouges
Carving out the inside of the back with thumb planes
Mode 5 309hz – early stage in plate tuning process
Mode 2 – early stage in plate tuning process
Roughing out inside of top with gouges and thumb planes
Mode 2 @ 130.8Hz on belly
Mode 5 @ 260.9Hz on belly
Final contours on back
Mode 2 @ 126.8Hz on back
Mode 5 @ 263.2Hz on back
Marking out f holes
f holes cut
Gluing in bass bar after chalk fitting
Initial mode 2 @ 133Hz after fitting bass bar
Initial mode 5 @ 282 after fitting bass bar
Mode 2 @ 127.1Hz on back
Mode 5 @ 262Hz on back
Mode 5 @ 255.9Hz 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
Gluing on the back
Adding the linings on the front after removing the form
Measuring mode 5 frequency (dropped to 227Hz) on the attached back
Blocks carved back and cleaned up ready to glue on the top
Gluing on the top
Box closed up
Neck blank trued up and marked up ready for carving.
Just needto add flutings now
The finished scroll
Fingerboard shaped
neck joint cut
Finished neck and fingerboard ready to glue onto body.
Gluing on the neck
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.
Here are some pictures of the finished instrument which weighs in at 522g (without chinrest):
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.
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.
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:
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.
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.