Question: floating bridge for nylon strings, and strut height/thickness

Construction and repair of Classical Guitar and related instruments
lamanoditrento
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by lamanoditrento » Thu Oct 26, 2017 2:08 am

Woah there is a lot going on in that guitar other than the bridge. Looks like a deep bodied parlour, shorter scale length plus split soundhole in the upper bout, adjustable soundport in the lower bout... let alone the what could be going on internally. Interesting sound though!

mitch lees
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by mitch lees » Thu Oct 26, 2017 8:24 am

In his books 'The Art of Tap Tuning' and 'The Luthier's Handbook', Siminoff makes the point that with a fixed bridge the dominant component of string vibration it the lengthwise vibration - this causes the bridge to rock back and forth thus transferring the motion to the top - the transverse vibration has little effect; for a floating bridge however, it is the cross vibration that dominates causing the bridge to move up and down and, presumably, from side to side, with the longitudinal vibration having much less effect. So, does the Vorreiter arrangement have the 'best of both worlds' - in that the floating bridge takes advantage of the transverse vibration and the fixed bridge plate uses the longitudinal vibrations? If that were so, why ever use a tailpiece? Seems too good to be true!

Mitch

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mayrluthier
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by mayrluthier » Thu Oct 26, 2017 3:57 pm

I'm currently cutting spruce leftovers to make the bracing for this top, which I already bookmatched last year; let's see how it ends up working out, just for kicks.

Alan Carruth
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by Alan Carruth » Mon Oct 30, 2017 6:49 pm

mitch lees wrote:
"...Siminoff makes the point that with a fixed bridge the dominant component of string vibration it the lengthwise vibration - this causes the bridge to rock back and forth thus transferring the motion to the top - the transverse vibration has little effect..."

I disagree strongly with him on this. I've never been able to duplicate his experimental findings, and have plenty of data of my own that contradicts them. Bridge rocking can contribute to the timbre of the guitar, but is not the main producer of power. I have plenty of data on that, too.

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mayrluthier
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by mayrluthier » Mon Oct 30, 2017 9:26 pm

I do find mr. Siminoff scientifically questionable, as well; he's indeed a marvelous, respectable craftsman, but many of his hypotheses on the physics of lutherie seem mostly like wishful thinking.

mitch lees
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by mitch lees » Tue Nov 07, 2017 5:44 pm

For those of us who are trying to build up a knowledge-base on subjects such as this, but who are not guided by a qualified teacher, it is difficult to know which sources one should rely on - that is why I find this forum so great. In my own, quite different area of expertise, I have frequently told students not to take everything they read on Wikipedia as 'gospel'. The same applies here and I am grateful for the reminder.

Alan - have you published/posted your data and findings, so that I can understand the counter-view?

thank you

Mitch

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rojarosguitar
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by rojarosguitar » Tue Nov 07, 2017 7:22 pm

Without wanting to develop a prejudice: In my experience with arabic ouds the transition from traditional (lute-like) to floating bridge in the modern Iraqui oud construction has caused a great loss of character and made the oud a much less charming instrument (in my ears, so may think differently).

I wonder if that's not going to happen with the CG as well if you do that, but of course it's a matter of experimentation.
Music is a big continent with different landscapes and corners. Some of them I do visit frequently, some from time to time and some I know from hearsay only ...

Alan Carruth
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by Alan Carruth » Tue Nov 07, 2017 7:26 pm

I did give a talk on the measurements I made on string forces on the saddle, and have posted a copy of it on my web site as a .pdf file. I've done other work on this line since, and have been trying to work it up in a form that will be acceptable for juried journal. It gets pretty complicated, though, and I'm not a practiced science writer. Also; you don't get paid for doing that stuff outside of academia, so it's hard to find the time.

es335
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Re: Question: floating bridge for nylon strings, and strut height/thickness

Post by es335 » Tue Nov 07, 2017 9:58 pm

Here is a floating bridge design which Dieter Hopf developped and patented in the 1980 under the technical term f.v.t.s. (free vibrating top system). It is discontinued now but there must be a sufficient number of f.v.t.s. guitars alive because they are still offering appropriate string sets from Savarez and Hannabach.

A sound sample can be heard here!

EDIT: What a coincidence. Siccas in Germany is is just recently offering a Hermann Hauser I spanish guitar model from 1920 with a floating bridge design in the bay! :wink:

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