Finished pics! Dreadnought for me?

impmann · August 2018

Superb as ever, Andy!

Andyjr1515 · August 2018

impmann said:

Superb as ever, Andy!

You are most kind

Teyeplayer · August 2018

Absolutely in awe of your skills. I thought the swift basses and @impmann ‘s alembic influenced build were fantastic but that acoustic! You keep surpassing yourself. I can see I’m going to have to start saving for a commission one of these days!

Andyjr1515 · August 2018

Teyeplayer said:

Absolutely in awe of your skills. I thought the swift basses and @impmann ‘s alembic influenced build were fantastic but that acoustic! You keep surpassing yourself. I can see I’m going to have to start saving for a commission one of these days!

Sounds good to me

Sporky · August 2018

How do you feel about making a cello?

Andyjr1515 · August 2018

Sporky said:

How do you feel about making a cello?

5th amendment?

Actually, I've had a cello neck for years to make an electric one. But the proper ones - they are made by magicians and pixies. They are not created from human hands - no way...not credible

Sporky · August 2018

Have a wiz.

Andyjr1515 · August 2018

Sporky said:

Have a wiz.

Have a LOL.

mli3 · August 2018

Iamnobody said:

Great stuff - thanks for sharing. I love build threads.

Ditto! Thanks

DartmoorHedgehog · August 2018

Looking very nice Andy

It's amazing how much wood will bend when it's wet.

@Sporky - are you suggesting the Sporkcello project is dead? nooooooooooooooooooooooooo.....!

Sporky · August 2018

It twitches occasionally.

Andyjr1515 · August 2018

Bit more progress in between the distractions of normal life!

The second side of kerfing strips was completed:

...and then back to the top to get it down from just over 3mm to closer to its final thickness. My hand arthritis is causing me gyp at the moment so I brought out the Stanley No80 scraper plane into action. I'd forgotten what a useful plane this is!

It made short but controllable work of the final thinning. After each pass, I picked up the top from an edge and rapped it with my knuckle. It had passed from drum thump to drum thump with one harmonic to drum thump and multiple harmonics - probably just going from 3mm to 2.8/2.9mm ish. Then one last pass and a change again - now even running my hand across the grain was making it ring out. So I've stopped. It's probably just under 2.8mm. Now I must stress I don't fully know what I'm doing on this sort of thing - I reckon to do that you have to sacrifice at least one top (or guitar) by taking it up to the 'oops - too far' - but I know from my last build that this is going to be strong enough and will be capable - if I get everything else right - of producing a nice sounding guitar.

Here it is laying on top of the 25' radius dish:

I was worried that the top might still be a little too stiff (and therefore too thick) but it presses into the dish no problem - the go-bar deck certainly won't have difficulties.

What is nice is that for the last dreadnought I built, I marked the brace positions on the radius dish so that I could sand them to the correct radius for each position. One less job this time around

Next task is the sound hole - but before you can cut the sound hole out you have to sort the rosette!

A Tasmanian member of one of the other forums on a visit to UK a year or so back presented me with a few nice sample pieces of local Tasmanian wood and the challenge 'to incorporate this onto one of your builds.'

Well - I reckon a book matched pair might do for the rosette!

First I thicknessed it on my bodge-home-made-job thicknesser jig:

That's gluing, then I can see if it will work OK as the rosette feature ring

Andyjr1515 · August 2018

So - time to add a swift:

And then cut out the rosette ready for installing:

BigMonka · August 2018

ooh I like the asymmetry of that rosette

Andyjr1515 · August 2018

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 c**k 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 for 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!

impmann · August 2018

C**k up or not. I think that is gorgeous, mate. I really like the assymetric nature of it..

Andyjr1515 · August 2018

impmann said:

C**k up or not. I think that is gorgeous, mate. I really like the assymetric nature of it..

Thanks, Tim

OK - 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...

Andyjr1515 · August 2018

I know what some of you are thinking.

You're thinking - 'Yes - Andyjr1515 is right. 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...

UnclePsychosis · August 2018

By most conventional measures I'm a pretty smart guy.

But this stuff is like watching actual genuine wizardry to me. Really enjoying seeing the process and trying to get my head round it at the same time! Keep it coming!

Andyjr1515 · August 2018

UnclePsychosis said:

By most conventional measures I'm a pretty smart guy.

But this stuff is like watching actual genuine wizardry to me. Really enjoying seeing the process and trying to get my head round it at the same time! Keep it coming!

Thanks! It delves further into black magic shortly. In fact - now!

OK - repaired 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!

Howdy, Stranger!

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Finished pics! Dreadnought for me?

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