Hybrid Possible?

[ozziebluesman]

The book set is a very useful resource and well worth having if you want to know how an acoustic guitar ticks.

Cheers

Alan

[Osbojo]

yup, will definitely get it. Found this site today which has whet my apetite:

Design of a classical guitar

Don't know enough to be sure of it's accuracy and he has an interesting view of bracing design. Worth a look though.

Os

[jeffhigh]

Yes that site is interesting. The radial top bracing is apparently prone to excess bridge rotation and his method of radial back bracing would be a bit soft for my preferences.
I also have an engineering background and find Trevors books make a lot of sense.

[Osbojo]

I remember reading somewhere about flying buttresses being used to counter rotation. The ones I saw were from the neck block to about halfway down the waist. They were clear of the top and bottom plates so I guess only stiffened the sides. would add a bit of weight I should think. Is the bridge rotation you speak of countered by this method?

[jeffhigh]

No the flying buttresses counter neck block rotation. I have not found them to be necessary.
The radial braced tops where the braces are not continuous through the bridge area are susceptible to the bridge rotating.

[Osbojo]

I see, I haven't experienced that yet although all of mine have suffered to a greater or lesser degree with bellying around the bridge. Not sure if I'm overthinning the top plate or under bracing.

Hmm, getting a bit off topic here, might upset the mods.

I started preparing the neck. Did the scarf joint on the headstock and attached the heel block. Laid it out for 44mm at the neck and for bolt on. Reduced the taper to about 54mm at the 12th fret and still the string spacing at the bridge comes out to the normal classical spacing. Not sure I understand that, would have thought it would have been less.

[jeffhigh]

http://www.buildyourguitar.com/resou...alc/fbcalc.pdf

[Osbojo]

Thanks Jeff. Easier to work backwards from standard spacing at the bridge but now I'll have to re-layout the neck. I ended up doing a spreadsheet to calculate the string spread at the bridge and was right, it was narrower than standard with 54mm at 12. Turned out to be 10.8mm dunno what I did when I scaled it. Now to decide whether to go with 12mm spacing at the bridge or stick to the 10.8 (11). I might make the bridge and leave the drilling till I see what the spacing and taper look like.

Os

[Osbojo]

Forgot to mention, ordered a copy of Gore/Gillett.

[Sebastiaan56]

Its worth searching the MIMF archives as well. I know there were a number of these instruments posted there.

[Osbojo]

Thanks Seb,

Haven't had much luck with the search engine on the new MIMF. I had a quick look through but couldn't find anything obvious. I'll spend a bit more time over the next few days and see what I can find.

[kiwigeo]

Do you have a copy of the Gore/Gillett books? If so, is it worth the $200?

Thanks again.

Os.

Youre playing around with the design of the guitar. Rather than make it a stab in the dark experiment why not turn it into a more planned exercise by reading Gore and Gilet's books before you get started. Im currently doing a falcate classical build based largely on G and G's methods.

Given a choice of spending $200 on the books or a master grade spruce top set Id go for the books any day.

[kiwigeo]

I might make the bridge and leave the drilling till I see what the spacing and taper look like.

Os

The string holes are the first thing I do when making up a classical bridge. if you do it after shaping the bridge then theres a risk of having problems such as the with drill bit wandering and not exiting the forward side of the tie block at correct location.

if youre not certain of spacing at the bridge then do up a mock up layout on a cardboard template and plot up strings on same.....I do it for all my builds.

[Osbojo]

Gore/Gilet books delivered today. Defnintely weighty tomes. Will have to get out my old maths and physics books for a refresher - 2nd order differential equations, determinants, even after spending 30 years doing electronics engineering in a science environment it'll be stretching the memory.

You're right Martin, need to get a bit more theory and avoid the temptation of just diving in. The books are worth every penny. I wish I had found these before doing my first, just the Build volume alone is worth the money, so much better value than Cumpiano when all's said and done. I'm surprised they haven't released the build volume as a standalone, I'm sure it'd go like hotcakes.

Os