Finished Pics! Dreadnought acoustic (guitar) for me?

[Andyjr1515]

Well, scraped and a quick coat of tru-oil.  Mmmm - that looks OK.  Better not wreck it - Tasmania is a long way to go to get another piece!

 

[Andyjr1515]

So - time to add a swift:

 

And then cut out the rosette ready for installing:

 

[Si600]

Erm, you did notice that your circles weren't concentric before you cut it out? 😜

[Christine]

This is so frustrating, on electric builds I can usually guess what's coming next but I'm lost here, I haven't the first clue So interesting

[Andyjr1515]

4 hours ago, Si600 said:

Erm, you did notice that your circles weren't concentric before you cut it out? 😜

What?

 

WHAT??

 

Damned varifocals!!!!! 

 

[RichardH]

I think the asymmetric rosette is a lovely touch - bravo!

[Andyjr1515]

5 minutes ago, RichardH said:

I think the asymmetric rosette is a lovely touch - bravo!

Ah....varifocals....love 'em    

[Si600]

It's quite interesting how non-bookmatched it looks once it's been cut out.  Especially missing the dark butterfly in the middle.

[Andyjr1515]

Onto the installation of the rosette and purfling circle.

This is a bit scary because it's got to be spot on.  And it involves routing a couple of mm out of a top that is only 2.7ish mm to start with!

First was to use the asymmetric holes in the centre of the cut out rosette as the template for a couple of similar holes in the top:

Then remember not to cut out the centre until I've routed all of the other bits!

First I routed the edges of the rosette - the inner using one of the pivot holes and the outer rout using the other one  :

So - what's going on on the right hand side?

Well - it's a good illustration of a little tip for acoustic guitar rosettes: leave the join lines / gaps and test the rout position always at the neck end of the circle. 

Why?

Because that will be covered by the fretboard

And so if you pink torpedo up your measurement, measuring from the wrong side of the router bit:

 

...then you can correct it for the full circle and the pink torpedo up won't show because the fretboard will be over it

Anyway - trying to remember which pivot hole to use far which area, I indexed the router a couple of mm each time each way to clear out the wood in the centre so I could fit the rosette

Then a 1mm slot on the outside for some purfling:

 

Then installed the purfling - it bends easily round this kind of radius dry and cold - and then some very careful scraping to bring the whole rosette down to top level and finally a deeper rout to cut out the sound hole.  And here we have it:

 

It's lucky that the c**k up slot is going to be covered, otherwise I'd have had to have added another piece of laminate as a 'feature' 

But luckily, on an acoustic, the fingerboard (or in my case it will be a stick on end magnetic pickup from a Shadow dual system) goes right up to the sound hole:

 

I've said it before.  Many regular builders will agree that we still make as many c**k ups as when we were beginners - it's just that we get more skilled at sorting out the consequences and hiding them! 

 

 

 

 

[Andyjr1515]

14 minutes ago, Si600 said:

It's quite interesting how non-bookmatched it looks once it's been cut out.  Especially missing the dark butterfly in the middle.

Yes - in a way a bit of a shame to lose so much of the figuring.  It will be enhanced, however, when the finish is applied.  Also it was too small a piece to use for the normal positions such as headstock plate, etc.. 

[Andyjr1515]

A bit of explanation in this post of some of the design and build features of a 'typical' steel string guitar for those who haven't ever built one but might.  I stress that, after building only two acoustics before, I'm no expert but it's OK because experienced acoustic builders will have 'unfollow''d this thread long ago  .    In my defence, this is still firmly in the basics territory, but it is info I would have appreciated understanding prior to embarking on my own first acoustic build.

First of all - what plan am I following?

Got one of the Elite Guitar Plans because it was easier than printing off the numerous versions on the internet and stitching together so many A4 sheets.  The design is the pretty ubiquitous one based on the Martin X brace design of yesteryear.  The plan is pretty good too, other than the spelling.

So the basics:

• The top is spheroidal, like a slice of a 25 foot radius football
• The braces not only transfer the string vibrations, via the bridge and underlying bridgeplate, to various regions of the top, they also form and hold the top in the 25' radius spheroidal shape.
• So the bottoms of the braces need to have a radius appropriate to were they will sit on the sphere
• And for that, we use the 25' radius dish again

In pictures:

First the braces are cut to profile.  These are flat bottomed at this stage so allowances need to be made in terms of the thickness.  I also leave them long so I can trim to my planned final length based on my actual sides assembly.

The plan shows where each of the braces will be positioned:

 

But, at the moment, they are flat bottomed - and they need to sit unstressed in their final positions in the radius dish so that, when they are glued down into the top - done also in the radius dish - they will force and hold the top in that spheroidal shape.  And at the moment they don't...yet:

 

It always surprises me just how curved 25' is!  

So - the next step is to curve the bottoms of each of the braces so that they sit in the dish with no gaps.

Then we can reveal the black magic of the go-bar deck

Hope that makes sense to those who are interested... 

 

 

Edited August 18, 2018 by Andyjr1515

[Andyjr1515]

Now then, I know what some of you are thinking.

You're thinking - 'Yes - 25 feet is a tighter curve than you imagine.  And surely he's going to run out of wood to get that X-brace to fit?'

 

Which is why I'm splicing extensions to the four ends of the X-brace struts... 

Another one for the Andyjr1515 bloopers DVD, @LukeFRC ? 

[Christine]

So the braces are actually laminated?

 

🤣

[LukeFRC]

2 hours ago, Andyjr1515 said:

Now then, I know what some of you are thinking.

You're thinking - 'Yes - 25 feet is a tighter curve than you imagine.  And surely he's going to run out of wood to get that X-brace to fit?'

 

Which is why I'm splicing extensions to the four ends of the X-brace struts... 

Another one for the Andyjr1515 bloopers DVD, @LukeFRC ? 

I work in marketing - if you ever go into acoustic guitar production I’m sure we trade mark and patent that and spin it as a positive ....:D

[Andyjr1515]

5 hours ago, Christine said:

So the braces are actually laminated?

 

🤣

Indeed - I expect the tone will be completely wrecked 

 

OK - laminates (I prefer to call them scarf joints  ) fixed means that the braces, fully shaped, now fit snugly in the radius dish:

 

So with a final scrape of the top to get the harmonics back now the stiffer rosette is in, I can mark the position of the braces on the top:

 

And then get out the SUPER HI-TECH GO-BAR DECK!

Yes...your eyes aren't deceiving you...can this really be just two pieces of chipboard held apart by a quartet of threaded rods with the radius dish vaguely plonked on top.  Yes it can!

What's it for?  Well, how else are you going to clamp down a set of different size braces across a .5mx.5m area, with enough force to press the top into the radius dish while securing all ends and middle of the braces for a strong glue joint....other than with something like a bendy dowel???

 

Aided and abetted by a few more bendy dowels and a herd of bendy fibreglass rods:

 

And to everybody's amazement the first time they try this - it works! 

[Christine]

So the shape of the dish becomes permanent when all the braces are glued in place, very clever!  Do you not lose the harmonic qualities (is that the right term?) of the top and bottom once they're braced like that?

[Andyjr1515]

4 minutes ago, Christine said:

So the shape of the dish becomes permanent when all the braces are glued in place, very clever!  Do you not lose the harmonic qualities (is that the right term?) of the top and bottom once they're braced like that?

No - it actually enhances it.  And we get to get into the really black magic world of tap tuning...

If you thought laminating was controversial.... 

I'll cover this soonish.

[pete.young]

On 03/08/2018 at 20:29, Andyjr1515 said:

 

But I've also been looking at the crazy amount of 'oooh that looks nice' wood that I've acquired over the past few years.
 

Hhmmm. Don't suppose you've got any Koa in that there woodpile?

[Andyjr1515]

1 minute ago, pete.young said:

Hhmmm. Don't suppose you've got any Koa in that there woodpile?

Hi.  No - not sure I've actually used Koa to be honest.  Exciting project in mind?

[Christine]

10 hours ago, Andyjr1515 said:

No - it actually enhances it.  And we get to get into the really black magic world of tap tuning...

If you thought laminating was controversial.... 

I'll cover this soonish.

The extra tension in the wood does it?

[pete.young]

11 hours ago, Andyjr1515 said:

Hi.  No - not sure I've actually used Koa to be honest.  Exciting project in mind?

I think so - I'm wondering what the alternatives to Anderwood might be for a nice Weissenborn lap steel.

[Andyjr1515]

1 hour ago, Christine said:

The extra tension in the wood does it?

I would be lying if I said I fully understood what exactly does what.

But when I was considering building my first acoustic I did a huge amount of reading and internet trawlingof what the high end makers do.  And then I went to a large guitar store and looked into the soundholes of a large number of steel string makes which bore out many of the things I'd read - that the great, great, great majority of steel strings are built to essentially the same formula

I followed every single one of the common features to the letter.  I was so pleased to have ended up with an instrument that actually held the tension of the strings that I'd have been chuffed if it had sounded like rubber bands over a baked bean can

But it sounded brilliant!  Like - better than my mate's Martin D18 brilliant!!!!

So how many builders and manufacturers actually understand why these features work - and understand enough to know what to tweak and where to make them even better - is probably relatively few.  I certainly don't.  But they - and I, now - do know they do work.  So, while most of my solid builds often go away from convention - and sometimes in a big way - for acoustics, I follow the formula slavishly.

And the elements in that formula?:

-  Almost all steel strings use a dished top.  There are only a couple of makers I know of who make a flat top

- The great majority of them use this identical bracing pattern - even down to a tiny sliver you will see me put on top of the x brace joint

- Even the position and height of the nodes on the braces are likely to be within a few mm of the same positions

- The back and sides makes very little difference to the tone. It pretty much matters not what they are made from as long as they are structurally rigid enough.  In many people's view, laminated sides and back makes no tonal or volume difference.

- The wood type, grain, stiffness and thickness of the top wood makes a very significant difference to tone

- As does the thickness and shape of the braces...which is where the black magic of tap tuning comes in (of which more anon)

[Andyjr1515]

With the main structural braces secure, I now am adding the side braces.  Although these also help to maintain the spheroidal shape, their main function is to transfer the vibrations to the various parts of the top.  These are the ones that will be tweaked during the tap tuning process.

First thing after the glue is set, however, will be to slim down the cross sectional profile of the braces into the familiar arch shape.

[Andyjr1515]

And tap tuning has begun 

Rather than me trying to explain how it works and what you do, this is one of the best explanations I've seen.  For those who REALLY want to know why and how - at quite a detailed scientific level - watch the whole thing.  For those who want to see - and hear - exactly what he does and what difference it makes to the sound, start at 30' in.

 

Anyway - he knows what he is doing and he does this for 8 guitars a week.  I don't and this is my 3rd acoustic 

But it's started and it's made a difference.  Mine doesn't sound like his, though 

Here's where I started:

And this is after slimming the struts to rough arch shapes (It's OK - it will be eventually sanded properly):

 

And since then, I've done a reasonable amount of tap tuning.  It's having the under-bridge plate glued at the moment - when that's set, I'll take a shot so you can see where and how I've tweaked the braces.

 

[Jabba_the_gut]

Interesting build this one. I like the offset rosette - nice touch!