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sospiri

String break angle 158 degrees? Where does that come from???

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1 minute ago, Riodifirenze said:

How much higher? 

As much as the arching is higher than whatever is the average.

We need to study the Stainer archives to agree on this. Some have been reset with higher neck overstand and look good to me. Some have a baroque style neck and normal arching by today's standards, like the one I posted on page one.

I think the baroque masters knew all of this and Vuillaume experimented with the Lady Blunt.

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15 minutes ago, sospiri said:

Fingerboard angle would be a better description than neck angle.

Specially for baroque violins

 

And yes string angle is critical for the downforce.

I personally don't like to much downforce, the more force you put on a spring the more it starts to act like a damper

 

But within the variables of string height above the fingerboard we can use relatively safe angles to avoid problems, then the player decides on the action or the luthier advises on the issue with input from the player.

Bridge height or more specifically string slot height, yes that's critical.

Because of the lever action of the bridge. 

 

Neck projection has been discussed in many threads and opinions vary, so I say 25 to 28mm is a good range. I also use mm with a low action on an 8 degree neck where I planed the fingerboard to get it down from 31mm. It works very well and the bridge height is within Michael Darnton's ideal numbers.

 

Edited by Riodifirenze
Answers in bold

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6 minutes ago, sospiri said:

As much as the arching is higher than whatever is the average.

We need to study the Stainer archives to agree on this. Some have been reset with higher neck overstand and look good to me. Some have a baroque style neck and normal arching by today's standards, like the one I posted on page one.

I think the baroque masters knew all of this and Vuillaume experimented with the Lady Blunt.

That makes sense, the higher the arching the higher the nut, right? 

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Just now, Riodifirenze said:

That makes sense, the higher the arching the higher the nut, right? 

Yes, I think so.

On the Lady Blunt, the nut seems to be so far below the bridge string slots that no good luthier would do something so extreme these days.

The main point of this thread is that nut height is critical. Saddle height and afterlength angles are much easier to adjust or correct  and can be altered. But we have to get that fingerboard angle right first time, every time.

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5 minutes ago, sospiri said:

Yes, I think so.

On the Lady Blunt, the nut seems to be so far below the bridge string slots that no good luthier would do something so extreme these days.

The main point of this thread is that nut height is critical. Saddle height and afterlength angles are much easier to adjust or correct  and can be altered. But we have to get that fingerboard angle right first time, every time.

That is the virtue of baroque violins you can change the fingerboard angle by changing their wedge to adjust the projection, but you can't altere the nut height by much so the neck angle is still critical. 

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If well-known best practices are used in cutting the bridge and the nut, as well as in attaching the tailpiece, how can the string angle become an issue?  Isn't focusing on the string angle by itself mixing up carts and horses? :huh:

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Lady Blunt isn't an example or source for modern setup.  Vuillaume was preserving a bit more of original than is normal.  Hence some distinct details.  

The original saddles tend to be actually flush with edge. Very different than modern raised saddles.

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5 hours ago, Riodifirenze said:

And yes string angle is critical for the downforce.

I personally don't like to much downforce, the more force you put on a spring the more it starts to act like a damper

If you put more force on a spring it acts like a spring with more force on it.  It doesn't act like damper.

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1 hour ago, Marty Kasprzyk said:

If you put more force on a spring it acts like a spring with more force on it.  It doesn't act like damper.

Yes, it was a bit over simplificated, a violin is sort of a complicated damped spring. The spring being the strings and the body a springy damper which instead of converting the energy of the strings, or springs in this example into heat, converts it into sonic waves. (heat losses still present) 

If you load the body to much it will loose its spring (resonant) properties and convert more energy into heat. 

 

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I believe the notion Riodifrenze is getting at is in the neighborhood of an idea I recognize but have troublr expressing or formulating well.

I make a fresh attempt.

Imagine two flat plates parallel to each and arrange so you somehow crank the plates closer or further apart, remaining parallel.

And you mount two springs, one on each plate, arranged so when you close the plates the spring will come together and compress each other in their natural lines of compression.

Now the basic idea is to trap a little something with a bit mass between these and consider different cases of behavior.  Particularly how the oscilates or responds to a driving signal.

We probably expect that a mass trapped between such springs will oscillate harmonically if disturbed, and respond to some degree if driven.

Ok.

But first, lets consider some degenerate situations with this rig.

If we try to trapsomething with too much mass for the springs, it'll just fall out. 

If we don't close the gap enough, our item won't be trapped.  Or, depending on shape, we might close the gap enough so the item doesn't fall out, but the springs also don't make clean solid contact, then our item will rattle around.

If our spring are too stiff compared to the item's mass, then the item will just be stuck in place.  And if we just crush the plates together excessively, similar things will occur.

Also, many odd behaviors can result if the spring strengths are very mismatched.

 

To me, it seems beneficial and interesting to considered under which conditions such a system would respond best to a driven signal of various natures.

 

 

 

 

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9 hours ago, Riodifirenze said:

 

If you load the body to much it will loose its spring (resonant) properties and convert more energy into heat. 

 

How did you come to that conclusion?

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30 minutes ago, David Burgess said:

How did you come to that conclusion?

Well remaining with the same example, to much tension in the sistem and the strings won't have enough strengt to excite the body beyond its damping properties. The oscillation (energy changes) of the strings will become to small in relation to the energy which tenses the body so it will simply "eat up" the strings energy. 

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The more tension there is in the body the more energy it takes to excite it into oscillation, I mean the harder the spring is tensed the less it will move with the same input of energy so less sound will be created. 

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Well there will be also more energy in the strings and this will take more effort to the player to bring them in motion with the bow(it's a harder spring).

So more downward force won't necessarily make the violin itself less loud but the player will have a hard time to get it in motion. 

Take a piano, it is a very hard spring so you need plenty of energy to get it to work, but then it will be very loud. 

A piano is a quite extreme example of a very hard spring (the strings)coupled very soft to the sound board (little downward force compared to the strings tension) so in a piano the sound board is very springy (it is not very tensed) and little dampy. 

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On 5/15/2019 at 8:46 AM, uncle duke said:

I don't understand the 5 degree, the number 82 or 8 degrees as well as the 84 degrees.  What are each of these numbers for?  

I wonder why she didn't answer to my question?

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2 hours ago, Riodifirenze said:

The more tension there is in the body the more energy it takes to excite it into oscillation, I mean the harder the spring is tensed the less it will move with the same input of energy so less sound will be created. 

In my own experiments, the spring rate of the top didn't seem to change with increases in vertical loading. It behaved like a linear spring, at least within the range of loadings I tried.

In other words, if a 5 pound load deflected the top 1 mm, a 10 pound load deflected it 2 mm, and a 15 pound load defected it 3 mm. So the amount of preload didn't seem like it would change how much the top moves due to string vibration.

This wasn't what I expected, but I got what I got.

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5 minutes ago, David Burgess said:

In my own experiments, the spring rate of the top didn't seem to change with increases in vertical loading. It behaved like a linear spring, at least within the range of loadings I tried.

In other words, if a 5 pound load deflected the top 1 mm, a 10 pound load deflected it 2 mm, and a 15 pound load defected it 3 mm. So the amount of preload didn't seem like it would change how much the top moves due to string vibration.

This wasn't what I expected, but I got what I got.

You and I differ. 

I would have expected what you got.

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20 hours ago, Riodifirenze said:

That is the virtue of baroque violins you can change the fingerboard angle by changing their wedge to adjust the projection, but you can't altere the nut height by much so the neck angle is still critical. 

Good point Riodiferenze.

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8 hours ago, Joey Naeger said:

Threads like this would be simpler if people submitted technical drawings instead of prose. Oh well. 

Not really related, but Sospiri, you might find the way I design bass necks interesting. Neck Geometry Tutorial

I don't understand CAD, but yes you are right, I should submit some drawings to illustrate my points.

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1 hour ago, David Burgess said:

In my own experiments, the spring rate of the top didn't seem to change with increases in vertical loading. It behaved like a linear spring, at least within the range of loadings I tried.

In other words, if a 5 pound load deflected the top 1 mm, a 10 pound load deflected it 2 mm, and a 15 pound load defected it 3 mm. So the amount of preload didn't seem like it would change how much the top moves due to string vibration.

This wasn't what I expected, but I got what I got.

You mean that the spring doesn't got harder with more load? 

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20 hours ago, David Beard said:

Lady Blunt isn't an example or source for modern setup.  Vuillaume was preserving a bit more of original than is normal.  Hence some distinct details.  

The original saddles tend to be actually flush with edge. Very different than modern raised saddles.

Yes David, but when you google  violin string break angle, it comes up with Peter K-G's drawing and thread.

Really 158 degrees is on the steep side for modern set up. Others have noted 160-162 which are good numbers to arrive at. I think we should really say 22 degrees (from horizontal) instead of 158. And I think 160 or 20 from horizontal is a better reference. Some of the drawings attempting to illustrate this issue are completely wrong and will mislead anyone attempting to work these angles out in their own set up.

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11 minutes ago, Riodifirenze said:

You mean that the spring doesn't got harder with more load? 

It doesn't. This seemed counter-intuitive to me too, so I had to try it for myself.

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9 minutes ago, David Burgess said:

It doesn't. This seemed counter-intuitive to me too, so I had to try it for myself.

Then where is the tension going? 

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