000 14fret shortscale acoustic build.
 

First post here.
This is Fran from Spain, long time amplifier/loudspeaker builder and about to build my first acoustic guitar. Thought I could share the process here, and ask for your help here and there.

It's going to be a 000 sized 14-fret to body guitar, with 24.9'' scale and 1 11/16 nut width. Adirondack top, indian rosewood back and sides.

Just finished gluing the top and back of the guitar and will start bracing both parts the next few days.

The problem is I'm following the plans found here:
http://www.grellier.fr/static/data/p..._guitar_fr.pdf

They're great and detailed, but correspond to a long scale guitar. I can calculate the bridge's new position but, what about the bridge plate under the top.
Should I modify the bracing pattern somehow to suit for the shorter scale?

Quite at a loss here, I'm afraid. Any suggestion will be strongly appreciated!

http://i38.photobucket.com/albums/e1...ps1aw385x1.png

Draw your guitar out, dont depend on the plans. The location of the bridge is fixed by its scale. The bridge plate has to go under the bridge and be a little smaller. Your X can go anywhere and the angle almost anything as long as it is under the bridge, about 100* is traditional. I think under the sides of the bridge is the best but it you want to control the bridge more you can move it to the back of the bridge. The rest of the braces can go anywhere, my opinion is that as it is your first you follow traditional placing. A little thicker bracing, say 5/16" X 1/2" is good for strumming, 1/4" X 1/2" for fingerstyle.

Thank you Mercy,
will follow your suggestions.

Got the radius dish and some homemade go-bars ready today, and will be bracing the top and back really soon.

http://i38.photobucket.com/albums/e1...ps2vitvfqn.jpg

I would be more concerned if you were going the other way round. For example going from a 25.4in scale to a 24.9. Even in that case you would probablybe fine but you want to make sure that the wings of the bridge are over the X-Brace arms else you risk the bridge peeling up at some point in the future.

And yes definitely take plans with a grain of salt. They are an aid but are generally overbuilt and sometimes make very bad mistakes.

You might consider opening the X-Brace on your shorter scaled guitar and or shifting it forward, it all just depends on what you are after.

Thanks redir,

I'm not sure I followed you, you mean you'd be more concerned going from 24.9'' to 25.4'', right?
Those plans I'm using correspond to a 25.4'' but I intend to build a 24.9'' guitar.

On the Norman Blake 12/14 fret 000 the braces just barely run under the front corners of the bridge. The forward tone bar is actually just under the rear corner of the treble side.
Granted, this isn't your standard bracing design, they sound really nice and I haven't seen one that failed. Though I've only seen a few.

Quite pretty.

Yeah sorry, I'm about as dyslexic as can be.

I've not yet bent two right sides before but came awfully close once.

Cheers mates,

I think I should stick to a more tradicional bracing pattern, nottypine, considering this is my first attempt at building an acoustic guitar. Still lots to learn!! Great to see some alternatives, anyway.

I started carving some pieces of spruce, and back braces are coming along nicely. Being the first time I use a chisel, I think I did a decent job.
I will remove some more wood once the braces are glued, but thought it would be good idea to shape them a little beforehand.

http://i38.photobucket.com/albums/e1...psjr3m7gwk.jpg

I like for the X-braces to intersect the lower corners of the bridge. That is the way most forward braced 1930's Martins were laid out. OM's were only produced until 1934, so all the originals are forward braced.
If you have an accurate OM pattern, you should move the braces (X, tone, finger) and bridgeplate up by 7/32" for the shorter scale. Soundhole and upper transverse brace locations are only moved up by 1/32". I always place the upper transverse brace 5/16" from the soundhole edge.
Measurements for the soundhole and bridge are from a 1931 OM-18 (25.4 scale) and a 1944 000-21 (24.9 scale).

Its your guitar but Id wait to carve the braces as it will be simpler to clamp with whatever method you employ

Wow that really helps, thank you.

Yes, I also carved so much wood from one of the braces that I wont be able to sand It to the correct radius.

Will make some new unshaped braces and shape them once glued from now on. :up:

Definitely wasn't promoting any one pattern but wanted to suggest that there are more than one set of rules.

Sure thank you Nottypine,
I really appreciate your suggestions.

I am currently repairing a Martin 000-15M 12 fret, here is a photo of the inside of the guitar top, it may help with your decision making regarding brace layout.

Steve

http://www.mirwa.com.au/images/BRPMN4.JPG

Dang dude, you got your hands full with that one :eek:

I would not call that a repair but rather a build :D

By the looks of it, forward X-Brace and wide open.

Is that a piece of NTSB evidence? Good lord.

Could the owner buy a D45 for what you have to charge him/her?

:) Just another day in the world of repairs.

Not as dear as you would imagine to fix, well under replacement value, and this one now has sentimental value to its owner

Steve

Thanks mirwa,
Wondered how the guitar ended up like that :cry: :cry:
Good luck with the repair!!

I'm struggling to route the rosette, as I thought would be better idea to route the soundhole and rosette prior to starting bracing the top.
What do you guys use to carve small circles?

I've got a makita rt0700 router and a dremel routing base, but both tools look too big for this small diameter routing job.

I can't imagine wanting to brace first, then cutting sound hole and rosette: it is much easier to cut the rosette, then sound hole, then brace.

You could use a circle (fly) cutter in a drill press or you could make/modify a router base/circle jig to make allow smaller holes. Typically, the router base interferes with the circle jig for small circles. Depending on the jig/router base, alter the base to accommodate smaller circles.

These days, I use an M-Power base on a full size router. Not cheap, but versatile and does a good job: http://www.leevalley.com/en/wood/pag...=1,43000,51208

Cheers Charles,
Glad I didnt start bracing, I was about to so when realised Its not a good idea.

I dont have a drill press, will try to alter the dremel base to acommodate smaller circles.

Fingers crossed, hoping i dont mess the top up

A quick update.
I routed a channel for the backstrip to realise most people sandwich the backstrip between both rosewood parts. :(

I glued it with cyanocrylate, but applied shellac first to the channel.

http://i38.photobucket.com/albums/e1...sbmodxgwf.jpeg

Here the result. Still plan to add a thin strip of abalone in the middle.

[http://i38.photobucket.com/albums/e1...psfevihta2.jpg

I've done both and haven't found it makes any difference. It is quicker and easier to sandwich.

That looks nice however, very tastefully done, did you apply shellac to the channel before gluing the insert in, is that what you were saying.

Steve

Thanks Steve, yes, I read you may taint the wood if you dont seal it first with some lacquer.

Hopefully your referring to protecting a stain from happening to areas not being glued, you really IMO don’t want shellac in the area being glued.

The jig I use comes from LMII, basically it scrapes a channel rather than cuts a channel, gives a super clean edge as per last macro attached, up close of the fit.

Steve

http://www.mirwa.com.au/images/RCH25.JPG

http://www.mirwa.com.au/images/RCH27.JPG

http://www.mirwa.com.au/images/RCH34.JPG

I'm afraid I applied shellac through all routed channel. Backstrip seems to be glued fine, though.

Lesson learned! I'll put shellac only to the surrounding area from now on.
Your cutting jig looks spot on! The edge is so clean.

Cheers,
Fran

If you will using CA glue (like for abalone) for binding/purfling it is recommended to seal the channel before gluing to prevent glue absorption. Dewaxed shellac works well in this case.

+1 on John
I think you are trying to seal any open end grain from getting the CA glue absorbed into it. When you rout the channel, there is end grain opened on the side of the channel.

This is great news, as I will be adding abalone to both top and back.
I applied unwaxed blonde shellac to the backstrip the other day. :up: