Making a guitar with Roy Courtnall

Construction and repair of Classical Guitar and related instruments
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tom0311
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Re: Making a guitar with Roy Courtnall

Post by tom0311 » Thu Sep 14, 2017 6:51 am

Malto069 wrote:
Wed Sep 13, 2017 10:40 pm
I've often looked to alternate sources of information and approaches in starting my first classical, but find I keep coming back to Roy's book - the other sources of information confuse the issue more often than not ;-)
The combination of this forum, the Courtnall book and the Cumpiano book have really helped me. Mind you all the pros (and a lot of the amateurs!) on this forum are producing ridiculously good work that sometimes makes me want to give up :P Make sure you take into account the neck angle on the Courtnall solera - I think in the book it is 3mm which might have been an error. There's a thread on here somewhere about it... if I remember correctly the thread is called "let's talk about neck angle". I think the recommendation was to shim that neck angle up to 1mm. Les Backshall put a good formula into that thread which helps you calculate correct neck angle, too.
“There are two means of refuge from the misery of life - music and cats.”

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josswinn
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Re: Making a guitar with Roy Courtnall

Post by josswinn » Thu Sep 14, 2017 7:12 am

Great to know this thread is of interest and use to people. Expect more photos and notes by the end of Sunday.

Recently, Roy posted about the solera error in the earlier printing of his book.
About the 3 mm solera slope - that was an error that somehow got missed. (Corrected in a recent re-print.) 1 mm is enough, or even perfectly flat. It does depend on the height of the dome at the bridge, and how much this collapses over time, if at all; and if the neck moves (less likely with a CF rod inserted), and so on. A flatter neck angle makes it easier to fit the fretboard.

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Re: Making a guitar with Roy Courtnall

Post by Abel Schmitt » Thu Sep 14, 2017 7:22 am

Wonderful work, Josswinn! Must be exciting to work with the likes of Curtnaill.
I'm very curious to see the continuation of the making... update us!!

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Re: Making a guitar with Roy Courtnall

Post by Jlrexach23 » Fri Sep 15, 2017 11:07 am

Simply awesome! Looking forward to see the finished product!

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josswinn
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Re: Making a guitar with Roy Courtnall

Post by josswinn » Sun Sep 17, 2017 6:44 pm

Day 8 (Courtnall book pp. 209-10; 229-232) Today, we began by laminating the back with the cherry and walnut veneers that we glued together last week. Using a scraper and abrasive paper, I ensured the joint was clean of glue and smooth, as well as sanding the cherry veneer to ensure a good flat gluing surface. Then, having pencilled the plantilla outline on the area of the walnut veneer which will show through the soundhole, I sanded it to bring out the grain. It was important to get the centre line of the burr walnut veneer in line with the centre of the back so that when looking through the soundhole, the grain of the walnut veneer was correctly placed. Because I am laminating the back, there is no need to strengthen it with a cross-grain reinforcing strip (pp.221-2). Here's the burr walnut veneer, already glued to the cherry, which was then glued to the walnut back. I think it will look nice when polished and viewed through the sound hole.

ImageSanding the walnut veneer for the laminate back by Joss Winn, on Flickr

Next, I bent the walnut sides, constantly checking the shape against an outline of the plantilla. I'm using the Friederich body from Roy's book.

ImageBending the walnut sides by Joss Winn, on Flickr

ImageChecking the ribs against the plantilla outline by Joss Winn, on Flickr

Again, you can see from the image above that the centre line of the guitar was marked on the template and I've almost got the rib bent to shape. I've yet to cut the wood to the correct length.

Once the ribs were bent to the correct shape I clamped each of them to a separate jig to help retain their shape:

ImageRibs bent and clamped until use by Joss Winn, on Flickr

Next, I cut a block of quarter sawn spruce into 23 strips for the struts and harmonic bars. As I said in an earlier post, there are 18 struts for the lattice. The struts will be further planed and carved to the correct size and shape and then reinforced with carbon fibre strips. Today, they were rough cut at 12 x 4 mm but the final width will be 2.0 to 2.5 mm. The height will vary, from 6 or 7mm over bridge tapering down slightly towards periphery.

ImageSpruce struts cut prior to shaping by Joss Winn, on Flickr

Finally, throughout the day I was attempting to create the log for the motif of the rosette. As I said in an earlier post, I wasn't happy with the first attempt because the ends of the square lines in each plank didn't align correctly due to them not being uniformly 1mm square. I'll post specifically about this next week when I have removed the glued log from the clamp and can compare it to the first attempt.
Last edited by josswinn on Sun Sep 24, 2017 7:04 pm, edited 1 time in total.

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Re: Making a guitar with Roy Courtnall

Post by josswinn » Sat Sep 23, 2017 7:39 pm

Day 9 (Courtnall book pp.201-207) Today I inlaid most of the rosette. As I mentioned on day 6, the first attempt at creating the log for the rosette motif was a failure. This was due to three reasons: My inexperience, the nature of the design, and being supplied with square lines that weren't uniformly 1mm.

I had asked my 10 yr old daughter to come up with a simple design for the motif. She decided upon our initials: J G S. When drawn on 1cm square graph paper this amounted to 11 columns and 5 rows plus a column at each end for spacing, so the finished log would be 13 x 1mm square lines across and five planks deep. Roy said this was not as simple as it seemed because it was wider than a typical motif and there was more opportunity for misalignment of the square lines. Furthermore, unlike an abstract pattern, the familiar lettering and monochrome (walnut/sycamore) tones made any mistakes immediately obvious. To add to this, the square lines were badly cut by the supplier and so I was dealing with variable width materials. You can see the first attempt on the right in the picture below with the second attempt on the left.

ImageThe rosette motif. 1st attempt (right). 2nd attempt (left) by Joss Winn, on Flickr

The second attempt was improved mainly because I asked the supplier to check the materials they sent me the second time around and I double-checked with a vernier caliper too. I also glued one plank at a time rather than all five at once, which helped me check the alignment at different points. I finished the second log off with sycamore veneer on the top, bottom and one side to provide more spacing when cutting each piece to fit the rosette circle.

I then cut each piece off the log, cut two circles, and chiselled out the waste.

ImageChiselling the 8mm rosette motif circle. by Joss Winn, on Flickr

Here are all the pieces glued in place:

ImageThe inlaid pieces of the rosette motif. by Joss Winn, on Flickr

And here they are having chiselled and sanded them flat with the sound board:

ImageSanded and ready for veneer inlays. by Joss Winn, on Flickr

I then cut the outer circle 5mm from the existing pieces:

ImageCutting the outer circle. by Joss Winn, on Flickr

Here I am chiselling out the waste again. This was probably the most nerve-racking task so far in making the guitar! I was scared of going outside the outer circle because it could mean I'd have to extend the width of the rosette further to rectify the mistake. I was also nervous about going too deep into the soundboard. Fortunately, it all went fine.

ImageChiselling the 5mm outer ring. by Joss Winn, on Flickr

I decided to decorate the motif with simple concentric circles of walnut and sycamore. Here's the outer veneer inlays glued into place and the inner veneers held in place to show you what it will look like. I didn't have time to finish it all off today but will do next weekend.

ImageAn indication of what the finished rosette will look like. by Joss Winn, on Flickr

I'm quite pleased with the rosette. It has my daughter's input, was technically demanding but instructive, and looks OK, too. From a distance, the lettering looks like an abstract pattern but also has personal meaning.

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josswinn
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Re: Making a guitar with Roy Courtnall

Post by josswinn » Sat Sep 30, 2017 9:10 pm

Day 10 (Courtnall book pp. 201-207; 237-239) I forgot my camera this week so used the camera on Roy's tablet.

I began the day by completing the rosette from last week. The inner circle needed to be cut and the veneer lines glued in place. Once it had dried, I chiselled and sanded the lines flat to the soundboard. One of them ripped slightly so I had to repair it, which wasn't difficult. A scalpel to clean the 2cm long slot, a small piece of replacement walnut veneer and a little glue was all it took. As it happened, it overlapped with the fretboard area, so is hidden for the most part.

ImageChiselling the rosette veneer lines by Joss Winn, on Flickr

I sanded the rosette and soundboard and then gave it a protective layer of shellac.

ImageProtecting the soundboard with shellac by Joss Winn, on Flickr

I'm quite pleased with the finished rosette. I wanted to learn the traditional techniques, which I think this enabled me to do; I wanted muted, natural colours, hence the simple combination of walnut and sycamore; and I wanted to involve my daughter in some way, hence her motif design.

ImageThe finished rosette by Joss Winn, on Flickr

Inbetween the rosette veneers drying, we laminated a side with two strips of cherry.

ImageLaminating the ribs with cherry by Joss Winn, on Flickr

Lots of grease proof paper and clamping from the centre outwards.

I also planed some struts to 2.5mm thickness and took the rest home to finish.

ImagePlaning the struts to 2.5mm by Joss Winn, on Flickr

I chamfered the lime linings. Here's one after planing but before sanding to a more rounded finish.

ImageChamfering the lime linings by Joss Winn, on Flickr

The linings are then kerfed and the two next to the soundboard will be laminated with veneer to make them more rigid.

Roy rigged up a box and spacer for the saw for me to kerf the linings. The spacer stops the saw cutting right through. Easy!

ImageBox and saw for kerfing the lime lining by Joss Winn, on Flickr

Very carefully, I turned the soundboard over onto a spotless, smooth surface and started to thin the back. The lower bout will eventually be thinned to about 1.3mm but today I took the whole board to 2.5mm. If you look carefully at the photo below, you can see lines where the plane has been. Upon inspection, the blade was slightly concave with the outer edges raised above the centre. I switched to another plane while Roy re-ground the blade to be slightly convex.

ImageThinning the soundboard by Joss Winn, on Flickr

The last photo from the day shows the rosette illuminated through the back of the soundboard. There's probably less than 1mm of soundboard under the rosette, but this will be reinforced with a circular piece of wood.

ImageThe rosette illuminated from the back of the soundboard by Joss Winn, on Flickr

Paul_NewBerlin
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Re: Making a guitar with Roy Courtnall

Post by Paul_NewBerlin » Tue Oct 03, 2017 5:41 pm

I too am following the steps laid out in Making Master Guitars for my first build. Everything you are showing is pretty familar. All I have left is binding, bridge, fret boad, and finishing. Unfortnately I have very little time to work on it lately.

I did scratch my head a little with the neck angle though and your notes are useful. One question I have for you, or Roy, is.... Should I have angled the top of the heel where the soundboard is glued? Mine is flat, thus my neck angle is flat dispite my solera being angled. It sounds like I should have angled it back 1 or 2°.

I'm glad I found your post. Most topics I am intersted in have threads that are years old.

Keep us up to date, and thanks!

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Re: Making a guitar with Roy Courtnall

Post by GeoffB » Tue Oct 03, 2017 11:17 pm

Hi Paul, welcome to the forum. Could I ask you to introduce yourself here?

Geoff
Classical Guitar Forum.

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Re: Making a guitar with Roy Courtnall

Post by josswinn » Wed Oct 04, 2017 12:37 pm

Paul_NewBerlin wrote:
Tue Oct 03, 2017 5:41 pm
I too am following the steps laid out in Making Master Guitars for my first build. Everything you are showing is pretty familar. All I have left is binding, bridge, fret boad, and finishing. Unfortnately I have very little time to work on it lately.

I did scratch my head a little with the neck angle though and your notes are useful. One question I have for you, or Roy, is.... Should I have angled the top of the heel where the soundboard is glued? Mine is flat, thus my neck angle is flat dispite my solera being angled. It sounds like I should have angled it back 1 or 2°.

I'm glad I found your post. Most topics I am intersted in have threads that are years old.

Keep us up to date, and thanks!
Thanks for your appreciative comment. I've contacted Roy about your question and the following incorporates his response:

You are obviously ahead of me in terms of build experience, but if you clamped the neck to the solera at the nut end, it should have set the angle in place.

If you are referring to the photo in the book on p.184 (12-34), you need to know exactly how thick the soundboard is where it joins the neck, which is why I've not yet made that recess as I've not finished the soundboard.

The recessed area should slope slightly because the neck itself, on the solera is (probably) sloping down at the nut end. It's a tiny amount over this short distance and depends on the slope if any on your solera. The first printing of Roy's book originally said 3mm, which was an error that was corrected to 1.5mm in later printings. But Roy says it can even be flat, depending on the geometry of the whole system and how much doming there is at the bridge. A high dome means that you are in effect raising the strings further at the 12th fret than if the dome is less. Also, how thick is the fretboard? This makes a difference. In a later session with Roy, we will draw it all out full size on paper to make it clear.

Roy said that he is "now making only a tiny slope, about half a mm, with a 2mm dome and 7mm fretboard, which all seems to work, giving the bridge string height I want. I want 10 to 12 mm string height at bridge for a lattice."

I hope that helps. If you or anyone else has any questions, do ask and I'll use my time with Roy to illustrate, document and clarify what we can. Other Luthiers may have alternative advice, so by all means pitch in.

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Re: Making a guitar with Roy Courtnall

Post by josswinn » Sun Oct 08, 2017 8:24 pm

Day 11: (Courtnall book pp.208-212) We began the day by laminating the second rib with two layers of cherry (see Day 10). It reminded me of the importance of doing a dry run of jobs like this so that all the components are in place (e.g. grease proof paper taped to the jig) and the clamps are to hand.

ImageGluing a rib for laminating by Joss Winn, on Flickr

Once the rib was clamped up, the focus for the rest of the day was the soundboard. To begin with, I marked the outline of the plantilla and the position of the 12th fret, 107mm from the edge of the soundhole:

ImageMarking the 12th fret by Joss Winn, on Flickr

I then roughly cut out the shape of the plantilla on the bandsaw and worked on thinning the soundboard by planing, scraping and sanding. I made sure the area that would be glued to the heel of the neck was consistently 2.5mm across and the thickness of the upper bout was also consistent (again, 2.5mm).

We used the dial gauge for the upper bout and then switched to the 'Magic Probe' for measuring the thickness of the lower bout. If you look carefully at this photo, you can see one round of measurements:

ImageMeasuring the thickness of the soundboard by Joss Winn, on Flickr

The process was to measure, pencil the thickness at different points (e.g. '17' = 1.7mm) and then sand using 100 grade paper; then measure again, pencil the new thickness across the lower bout and then sand again. Each round of sanding would take off about 0.1-0.2mm. You can see in the photo that as we get nearer to the rosette, the thickness increases to over 2mm. The aim was to achieve a maximum of 1.5mm across the lower bout and especially around the bridge area. 1.5mm at this stage allows a further 0.1-0.2mm to be taken off the front when finishing the soundboard. The final round of sanding on the back of the soundboard was with 180 grade Garnet paper. The lowest reading today was 1.35mm:

ImageThe finished thickness of approx. 1.3-1.4mm by Joss Winn, on Flickr

The next job was to cut and reinforce the soundhole so the glue could dry over lunch. After lunch, I trimmed the soundboard with a scalpel at the position of the 12th fret (see illustration 19-3 in Roy's book) and marked the centre line of the guitar. From there, I marked out the bridge, the lattice struts and the area of the lining:

ImageReinforced sound hole and bridge and lattice marked out by Joss Winn, on Flickr

I then bolted the soundboard to the solera and took the opportunity to mark the heel of the neck where the soundboard will fit into a recess (see comment above):

ImageMarking the heel with the soundboard thickness (2.5mm at the neck) by Joss Winn, on Flickr

The last job of the day was to shape the 18 struts for the lattice. They had been planed to 2.5mm thickness and needed to be cut to length and marked to account for the dome of the plantilla.

ImageShaping the lattice struts to fit the dome of the solera by Joss Winn, on Flickr

Each pencil line of the lattice was either given a letter (A, B, C, etc.) or a number (1, 2, 3, etc.), with letters perpendicular to numbers. Then, each strut was cut to the length of a lattice line and labeled with the corresponding letter or number. To trace the dome of the plantilla, I pressed the soundboard down while running a pencil horizontally across the strut which rested lightly on the soundboard. I then planed and sanded down to the line, checked the fit and sanded again if necessary.

TJ2
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Re: Making a guitar with Roy Courtnall

Post by TJ2 » Fri Oct 13, 2017 3:33 pm

Thanks for sharing this project with us. I'll be following as well.

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josswinn
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Re: Making a guitar with Roy Courtnall

Post by josswinn » Sat Oct 14, 2017 8:10 pm

Day 12: (Courtnall book p.124; 184) Today we drilled the sound port, cut the recess in the neck for the soundboard, made wedges to fix the ribs to the neck and constructed the lattice for the soundboard.

I've read the discussions on this forum and here and here about sound ports and wanted to include one on this guitar more for the experience of creating one than any possible benefits to the sound. (Likewise, I will be making an arm rest because I want to use my time with Roy to learn how to make one). For the sound port, we calculated the eventual centre of the rib, taking account of the 86mm final width, which includes the depth of the back, ribs and soundboard. I then cut a block of wood to the shape of the area of rib I would be cutting so that I had something to drill into and stop the drill bit from splintering the rib. The underside of the wood block sat flat on the drill press stand and Roy held it all tight while I cut through the beautiful piece of walnut(!):

ImageDrilling the sound port by Joss Winn, on Flickr

All was well. In the photo above, you can just see the remains of the cherry veneer on the right of the hole, which was removed with another press of the drill.

Next, having marked (last week) the heel of the neck where the soundboard would be glued, I removed the wood with a chisel and rasp to form the recess. Roy explained the issue that was raised above and showed me how the depth of the dome, the height of the saddle, the angle of the neck, and the depth of the fretboard all interact when setting the action of the strings. I am following Roy's current practice of a 2mm dome and 7mm fretboard, with hardly any angling of the neck where it meets the soundboard. Today, I cut it flat and can add a 0.5mm angle later if necessary:

ImageCutting the recess for the sound board by Joss Winn, on Flickr

The reason for cutting the recess today was so I could cut the ribs to the right length and shape the wedges that will hold the ribs in place. This was a case of cutting two wedges out of a Cedrella offcut and then carefully reducing them with a plane, rasp and sandpaper so that each fitted nicely and pressed the rib against the face of the slot. Here's a wedge that's almost there:

ImageShaping the wedges by Joss Winn, on Flickr

The ribs and wedges still need to be cut down to their final width/length, but that's for another day.

Throughout the morning, I was gluing the struts I had prepared earlier to the soundboard. I glued three at a time, which involved some careful clamping:

ImageClamping the struts by Joss Winn, on Flickr

Once all of the struts in one direction of the lattice were glued, I planed them down to a height of 6mm, measuring the high point with a vernier caliper and tapering them off a little at each end. I then took a sanding board and went across the width of the lattice to finish them off before adding the cross-struts. This involved using a scalpel and 1mm chisel to mark and cut slots halfway through the depth of each strut where they crossed. Here's a picture towards the end with just two more struts to go before gluing and clamping again:

ImageBuilding the lattice by Joss Winn, on Flickr

The sound port and lattice struts were not part of Roy's original book but the website we're building will include more photos of these processes in addition to other updates to the book. There is likely to be approx. 500 photos on the finished website offering much more detail than I provide here.

khayes
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Re: Making a guitar with Roy Courtnall

Post by khayes » Sat Oct 14, 2017 9:56 pm

Thanks for posting your process - I look forward to it every week. Looks like you're making the most of a great opportunity.
Ken

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Re: Making a guitar with Roy Courtnall

Post by Elman Concepcion » Sun Oct 15, 2017 12:04 am

josswinn wrote:
Sat Oct 14, 2017 8:10 pm
Day 12: (Courtnall book p.124; 184)

Once all of the struts in one direction of the lattice were glued, I planed them down to a height of 6mm, measuring the high point with a vernier caliper and tapering them off a little at each end. I then took a sanding board and went across the width of the lattice to finish them off before adding the cross-struts. This involved using a scalpel and 1mm chisel to mark and cut slots halfway through the depth of each strut where they crossed. Here's a picture towards the end with just two more struts to go before gluing and clamping again:

ImageBuilding the lattice by Joss Winn, on Flickr
Hi josswinn
That method of fitting the lattice seems like a lot of work. IMHO.

Just a suggestion.

It would be easier.
If you build the lattice structure off the top.

Once it is build, you can sand it down so all joints are flushed.
i.e. you can over shoot the pockets and then sand any errors back to flush.

Then use fish glue on all the matting surfaces and then place it on the top and use a vacuum table to clamp it over night .
There are other methods of clamping with out a vacuum table but they are not as worry free.
Next, you can use a curved radius sanding block to do some graduations.
I realize you may not have a vacuum table but in future this would save you a lot of time.

Hope that makes sense.

Thanks for this thread It's great !!!
I'm also teaching someone how to build a guitar and I send him here to observe your progress :-)

Cheers
Elman

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