The Apprentice

[rickoshea]

with the braces remodelled its time to get them onto the soundboard. A nice tight fit is essential between them so it took a bit of time to sand in the angles required. The first to go on are the radiussed braces on the lower bout .... so they're glued in the go-bar deck on top of the 30' radius dish :







I made cauls for the soundhole braces which are glued with the go-bar deck turned over to give a flat surface. The top in the upper bout has to be flat to accomodate the fingerboard :



the rosewood bridge reinforcement plate is also cut from a template thats made from the plans and fitted snugly between the x braces. This will also have an influence on the final tone :



now we move onto carving the braces to adjust and create the actual tone thats going to come from the guitar

[Gary Palmer]

Looking swell.

[garthman]

ET phone home?

[rickoshea]

ET phone home?

lol!! .... I know, its damned weird looking and again, prone to taking an eye out if you're not careful

with the braces on its time to do a bit of sculpture on them . They need shaped to allow the soundboard to deflect and vibrate, mostly in the lower bout region. I've chosen not to scallop the length of the braces but the ends will be scalloped 6.5mms from the closest point of the side. This is to do with magic. Or maybe its because this is where they have to be to produce the best tone ... its a "nodes" thing I think (I'm sure Gary can explain it better if anyones interested ). The x braces are commonly tucked into the kerfed lining in the sides but I've decided to leave them clear by 3mms. This should pronounce the bass a touch more.

chisels .... sharpened chisels. Great fun to use and very fond of embedding themselves in my fingers. Scalloping one of the lower x braces (the metal rules protect the soundboard and give an indication of the final thickness of the ends of the braces) :



All the braces are worked with the chisels, and at stages the soundboard is tapped whilst holding it between forefinger and thumb. We're looking for around an F/F# on the tuner. Mine seems to lie in between the two . So here's the final result :





The upper braces will tuck into the linings so are left long.

Finally the thin transverse graft needs adjusted to allow for truss rod access using a round file :



and this part of the bracing process is done :

[gitnoob]

We're looking for around an F/F# on the tuner. Mine seems to lie in between the two .

Great work, and great documentation!

The "magic" part is the stuff I was most curious about. It sounds like you didn't do any deflection testing (or any determination of vibrational nodes), but just went for the tap tones.

So what was the starting tap tone, and how did the brace shaving change that tone? Removing material lowers the frequency, right?

[rickoshea]

Great work, and great documentation! The "magic" part is the stuff I was most curious about. It sounds like you didn't do any deflection testing (or any determination of vibrational nodes), but just went for the tap tones. So what was the starting tap tone, and how did the brace shaving change that tone? Removing material lowers the frequency, right?

Thanks

no - I didnt do any deflection testing or node finding. I have no means to thickness the LMI soundboard for this build plus the bracework was pre-carved (that was an ordering mistake - I should have done that bit myself) so that element of voicing is lost unfortunately. I'm sure Gary will explain this better but ....

tap tone is a tricky thing for me still and really is something that can only come with experience. I started out by getting many different tones as I was tapping differently, holding the board differently etc etc. When I finally got some consistency I was at first just listening for some sustain ("some" being about a second I believe), and trying to listen for a nice "ring" from the board rather than a dull "thud". Initially I was getting an F# (usually ). Removing material allows the board to vibrate more freely and lowers the frequency yup. After carving I'm now closer to an F. Gary told me that you can bring this lower by more carving as, once the bridge is fitted, the string tension stiffens the board again. I think you aim for a final tone of F to F#, so I can bring this down more by more carving of the braces. We're going to fit the top first then work further on the voicing to try and get close to this. The bracing pattern we've done is a forward shifted X, with the x braces at right angles. Splaying these braces a bit would have allowed the lower bout to resonate more and made the tone more bassy (correct me if I'm wrong Gary as I think thats what I saw on Ervin Somogyi's video ... I have a memory like a sieve ). I'm chasing the Yamaha LL tone though so I want to get a more rounded, defined final result

[Gary Palmer]

Great work, and great documentation! The "magic" part is the stuff I was most curious about. It sounds like you didn't do any deflection testing (or any determination of vibrational nodes), but just went for the tap tones. So what was the starting tap tone, and how did the brace shaving change that tone? Removing material lowers the frequency, right?

 

 

 

 

The soundhole being already cut left an incomplete soundboard to deflect/test and virtually nullified the opportunity to check nodal response if Rick had wished to pursue that route.

 

Despite the possibility to carry out deflection tests on bracing stock, again, a snag exists in terms of the braces being pre-profiled, so not too much could be done by virtue of adequately assessing and calibrating stock prior to profiling.

 

Materials removal can either lower, heighten, or shift frequency. As can brace mass, density, placement and contour.

 

In essence the starting tap tone is what Rick has published and results from laying out a bracing design adapted for use on this particular instrument and combination of tonewoods. Instead of following rigid kit plans, it's voice can now be refined during the various build stages that follow. Rick has already covered much of what I'd have said.

 

In truth a guitar needs to be in tune with itself, so we refine voicing until we reach a state of equilibrium between materials and body size. Coming from a violin making background I tend to have given target tones to aim for during each step while targetting a particular end result as the bridge and string tension are added.

[rickoshea]

The soundhole being already cut left an incomplete soundboard to deflect/test and virtually nullified the opportunity to check nodal response if Rick had wished to pursue that route. Despite the possibility to carry out deflection tests on bracing stock, again, a snag exists in terms of the braces being pre-profiled, so not too much could be done by virtue of adequately assessing and calibrating stock prior to profiling. Materials removal can either lower, heighten, or shift frequency. As can brace mass density, placement and contour. In essence the starting tap tone is what Rick has published and results from laying out a bracing design adapted for use on this particular instrument and combination of tonewoods. Instead of following rigid kit plans, it's voice can now be refined during the various build stages that follow. Rick has already covered much of what I'd have said. In truth a guitar needs to be in tune with itself, so we refine voicing until we reach a state of equilibrium between materials and body size. Coming from a violin making background we tend to have given target tones to aim for during each step while targetting a particular end result as the bridge and string tension are added.

just when I think I know something - thanks for correcting me mate

a wee point here as well. Usually it takes quite a bit of work to get to an F# when tapping ... loads of brace trimming etc. Gary did some brilliant technical drawings for me of the exact dimensions and placement of the bracework I needed in order to go for the LL tone. I copied these exactly when initially diverging away from LMI's plans and re-doing the braces. Once fitted they gave an F# tone with no carving at all ........ pretty damned accurate drawings Gary! - thanks

[Gary Palmer]

just when I think I know something - thanks for correcting me mate a wee point here as well. Usually it takes quite a bit of work to get to an F# when tapping ... loads of brace trimming etc. Gary did some brilliant technical drawings for me of the exact dimensions and placement of the bracework I needed in order to go for the LL tone. I copied these exactly when initially diverging away from LMI's plans and re-doing the braces. Once fitted they gave an F# tone with no carving at all ........ pretty damned accurate drawings Gary! - thanks

I hadn't meant to correct you - we posted simultaneously methinks - but you're more than welcome in terms of any drawings I've done mate. I'd simply call it an educated guess based on what you had to work with and we took it from there. You did the real work.

[gitnoob]

The whole "target an F# tap tone" bit is pretty fascinating to me. I think this is what separates factory-built guitars from hand-built.

 

Seems like whatever you get from a factory will be randomly "tuned." You may get wolf tones, you may get a string that sounds underpowered, or you may get lucky.

 

My understanding is that the F/F# target is empirically based (rather than theoretically based). It just sounds "good" to have the main body resonance frequency to be slightly off from the fundamental string frequencies. And there are various combinations of the top-to-back resonance and the Helmholtz resonance frequency of the air cavity that sound "good" as well.

 

Verrrry interesting.

[Gary Palmer]

The whole "target an F# tap tone" bit is pretty fascinating to me. I think this is what separates factory-built guitars from hand-built. Seems like whatever you get from a factory will be randomly "tuned." You may get wolf tones, you may get a string that sounds underpowered, or you may get lucky. My understanding is that the F/F# target is empirically based (rather than theoretically based). It just sounds "good" to have the main body resonance frequency to be slightly off from the fundamental string frequencies. And there are various combinations of the top-to-back resonance and the Helmholtz resonance frequency of the air cavity that sound "good" as well. Verrrry interesting.

Factory built instruments built to a desired tone, but this tends to be on a law of averages basis and they're seldom voiced individually. This is much the reason behind variance in end results and the need to select from a few rather than distance buy if you wish to guarantee picking up something you'll like.

The in-between frequencies and being able to contour them are aspects that make an instrument sound good, while in balance with body style, volume, etc., etc., etc..

[kwakatak]

I have a question for you guys. Do you find yourself sacrificing time playing your other guitars while you're in "luthier mode" or does part of you still think like a player who's watching their new baby take shape? These pics and the responses kind of mirror the feelings I was having when I first saw ultrasound images of my first son.

Also, after you're done are there ever any regrets? It's not exactly like buyer's remorse is it?


...I'm just trying to justify the idea of me doing a build. My wife has already mocked me when I mentioned it, saying that I never finish anything.

[LaurentB]

l(...) We're looking for around an F/F# on the tuner. Mine seems to lie in between the two

Mine sounded like an F# as well.

[rickoshea]

Mine sounded like an F# as well.

Well hopefully I can get mine to sound like yours Laurent ... all will be good then

[Gary Palmer]

I have a question for you guys. Do you find yourself sacrificing time playing your other guitars while you're in "luthier mode" or does part of you still think like a player who's watching their new baby take shape? These pics and the responses kind of mirror the feelings I was having when I first saw ultrasound images of my first son. Also, after you're done are there ever any regrets? It's not exactly like buyer's remorse is it? ...I'm just trying to justify the idea of me doing a build. My wife has already mocked me when I mentioned it, saying that I never finish anything.

Luthiery and guitar playing tend to be separate issues for me, although I keep a guitar or violin handy in the workshop for chill out moments. After close to 40yrs working professionally as a luthier I still gain a great deal of satisfaction from the craft and just as much enjoyment from playing and making music. I'm either building them, playing them or designing instruments and equipment.

You never stop learning, so there's little - if any - chance of my approach becoming stale or a chore, as each and every build is also a search for improvement upon the previous one.

Life's far too short for regrets and seeing an instrument leave the workshop gives me a great deal of satisfaction, as I know the person who's bought the instrument will gain just as much enjoyment from playing as I had building it, but from a craft and player standpoint it won't leave the shop until it's wholely playable and without flaws. It's good to see them go to good homes.

[kwakatak]

Life's far too short for regrets and seeing an instrument leave the workshop gives me a great deal of satisfaction, as I know the person who's bought the instrument will gain just as much enjoyment from playing as I had building it, but from a craft and player standpoint it won't leave the shop until it's wholely playable and without flaws. It's good to see them go to good homes.

Funny you should put it that way, Gary. Over on AGF there's a "bucket list" thread and this entered my mind - as well as commissioning a build from a friend. As for building my own, I of course hope to get many years of enjoyment out of it but I'd also be happy to pass it on to one of my kids one day. As for commissioning one from a friend, probably the biggest factor against it was that I couldn't give it a good home.

[rickoshea]

Funny you should put it that way, Gary. Over on AGF there's a "bucket list" thread and this entered my mind - as well as commissioning a build from a friend. As for building my own, I of course hope to get many years of enjoyment out of it but I'd also be happy to pass it on to one of my kids one day . As for commissioning one from a friend, probably the biggest factor against it was that I couldn't give it a good home.

.... and I cant think of a better reason to build a guitar

[kwakatak]

.... and I cant think of a better reason to build a guitar

Yeah - it might be a few years down the road though. My little guy slammed the lid on my Larriv

[Gary Palmer]

Yeah - it might be a few years down the road though. My little guy slammed the lid on my Larriv

[LaurentB]

Well hopefully I can get mine to sound like yours Laurent ... all will be good then

I have been playing it every day since it was finished, with exception of the weeks I was in the US.
You're going to have a great instrument!

[rickoshea]

this time I was delayed by a weird French virus that decided to take roost in various regions of my body and definitely wasnt conducive to guitar building

Today things are a bit better so its time to get the top prepared for glueing onto the sides. The upper face braces and the transverse graft are going to be tucked into the linings to give this area a bit more strength. This meant that the lining needed to be notched a bit so all would fit together. Out came the trusty dremel and dental burs , the bits to be removed I marked on the kerfling but they're adjacent to the blue lines :



the bur is set to the right depth against the braces and tried against the linings :



and the cuts made (carefully lol) :





we decided to sanding seal the top at this stage to protect it using a shellac/denatured alcohol mix - the bearclaw spruce now shows a bit of its character :



the soundboard goes on next then some more work on the voicing

[garthman]

That top looks good

[gitnoob]

Just curious how you transfered the location of the braces to the kerfing, as I assume this has to be precise. You need to nail the location, width, and the depth exactly in order to have good gluing surface contact, right?

[rickoshea]

Just curious how you transfered the location of the braces to the kerfing, as I assume this has to be precise. You need to nail the location, width, and the depth exactly in order to have good gluing surface contact, right?

as precise as possible yup. Its all to do with centrelines and alignment. If you look at the soundboard you'll see I have squared it off at exactly 149mms from the centre of the soundhole (which involved some good old fashioned geometry using chords to find the centre of a circle). The centrelines are marked exactly on the soundboard and the rims (sides). Basically the top is precisely aligned where it should be and the offending braces then sit proud of the linings. This is marked on the sidewood then transferred to the linings. The depth is then set on the router base using the braces themselves. After that its a matter of removing the lining bit by bit between the marks whilst constantly trying the soundboard on the rims until it slots home. I was removing maybe 0.5mms at a time and then setting the top on. It took a while but all slots home nicely now . Some of this is of course going to be removed during the prep for the binding and purfling.

I could have done the job using chisels but for me its more accurate using the handpiece and a bur

[rickoshea]

soundboard glueing time ..... I made a load of wee cauls and chopped a bit off my go bars so I could glue on the top in the go bar deck. Its a bit important to get the top aligned perfectly at the lower and neck ends for obvious reasons. This is one step where you have to work efficiently. This means bloody quickly lol :



the top with the zebrano back and sides (still to be trimmed flush) .... it all ties in just fine :



that was yesterday. Today I got to work on some of the voicing of the guitar again. A bit of tapping on the board later and a reasonably constant F - F# was the result. Some material can be removed to bring this down a touch (free up the soundboard in other words) so out came the chisels and I did some profiling of the x braces and lower face braces:



a dowel rod rolled in fine grit paper is just the job for sanding in a nice curve at the start of the scallops :



just about there :



during this theres a lot of measuring the tap tone change that results from the profiling. It gradually came down to an E# which is hopefully going to be pretty close to the Yamaha LL16 tone when all is said and done. Further adjustments can be done once the back is on if necessary :



One often overlooked process in building a guitar and one thats central to the build is ...... signing the braced soundboard . Maybe someday someone will wonder just who the hell I was lol :



and the final result :



now onto the back ....