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H.R.Fisher

plate tuning specs ?

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On 12/5/2017 at 3:07 PM, H.R.Fisher said:

    Your input will be greatly appreciated.   Thanks,   Henry

     Top plate wt. w/  BB and ff     71gr

            Tap tone both top and back       F

      Mode  1    Top    99hz                            

      Mode 5        Top     370 hz                          

 

Let's  see -  370 multiplied by 370 multiplied by a plate weight of 71gr. = still to heavy, imo.    

The mode 1 is sorta getting close so if you decide to keep thinning - be careful.

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1 hour ago, Emilg said:

where! where! :lol:

here''s something that could help.......... I can't remember who said this a few years back but I believe just for the time being that he is 2/3rds right.  

 .........for more power and less complexity take away some of the curvature and make the center more of a flattish plateau.  For a sweeter, more complex tone with less power take the recurve further into the plate [long arch wise] and add a more curved profle from the trough to the peak.  Doing so adds complexity to tone at the expense of power.

The other 1/3rd of the 2/3rds rightness may have something to do with getting lucky by choosing the right piece of wood, correct arching profile for that piece of wood, the height needed and just plain old luck while going through the rest of the making process.    

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2 hours ago, uncle duke said:

here''s something that could help.......... I can't remember who said this a few years back but I believe just for the time being that he is 2/3rds right.  

 .........for more power and less complexity take away some of the curvature and make the center more of a flattish plateau.  For a sweeter, more complex tone with less power take the recurve further into the plate [long arch wise] and add a more curved profle from the trough to the peak.  Doing so adds complexity to tone at the expense of power.

The other 1/3rd of the 2/3rds rightness may have something to do with getting lucky by choosing the right piece of wood, correct arching profile for that piece of wood, the height needed and just plain old luck while going through the rest of the making process.    

thanks Uncle, like others i have been eye balling the arches sofar, but i think it's time to give it a little more attention, keeping this sort of directions in mind

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4 hours ago, uncle duke said:

Let's  see -  370 multiplied by 370 multiplied by a plate weight of 71gr. = still to heavy, imo.    

The mode 1 is sorta getting close so if you decide to keep thinning - be careful.

 

Final specs:

top 66gr w/ BB  ff

back 117 gr  [ very dense wood]

mode 1    T 96hz   B 116 hz

mode2     T 164hz  B 164hz 

mode5     T  355hz   B 339hz

The back rather heavy and already quite thin and my resource tells me  mode 2 top and back should be equal.

I'll see how it works out.

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H.R. What does your gut tell you? And then is it the same as you usually end up with or different and what's different? I'm in the camp of arching, if it's good and you do a reasonably good job on the rest of the details you end up with a decent fiddle. As the younger folks say... send it!

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44 minutes ago, H.R.Fisher said:

 my resource tells me  mode 2 top and back should be equal.

 

Not necessarily, do not trust your resource too much....;)

I'm not saying that they can not be the same, but if I were your resource I would tell you not to worry too much about the M2, I would say just to separate it from the M5 in the top as much as possible (more than an octave), in the back might also remain the same (of course an octave below).
But then again, do not believe too blindly what you hear from others (me included:)), especially when it leads you to do strange things with thicknesses that you have never seen in good violins, which are the only true resource to be trusted.
 
I warn you, no one has your plates in his hands and so can not have the full picture to be able to make accurate decisions.

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7 minutes ago, Mike Spencer said:

H.R. What does your gut tell you? And then is it the same as you usually end up with or different and what's different? I'm in the camp of arching, if it's good and you do a reasonably good job on the rest of the details you end up with a decent fiddle. As the younger folks say... send it!

  As an aspiring maker I am exploring various methods and techniques to come up with predictable results. I have built two dozen plus fiddles, some fairly good  some not so good concentrating mostly on construction, dimensions, thickness etc. I want to give more attention to tap tones, modes flexing and so on ,perhaps some day I'll be able to make an excellent instrument.

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Just now, H.R.Fisher said:

  As an aspiring maker I am exploring various methods and techniques to come up with predictable results. I have built two dozen plus fiddles, some fairly good  some not so good concentrating mostly on construction, dimensions, thickness etc. I want to give more attention to tap tones, modes flexing and so on ,perhaps some day I'll be able to make an excellent instrument.

Maybe tomorrow, if you have the needed luck.:P

The real problem will be to be able to make excellent violins with a certain constancy, not just one.....

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1 hour ago, H.R.Fisher said:

my resource tells me  mode 2 top and back should be equal.

1 hour ago, Davide Sora said:
Not necessarily, do not trust your resource too much....;)

Resource screening factor #1:  is the resource known to consistently produce world-class instruments?

(FWIW, my own opinions are similar to Davide's)

 

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1 hour ago, H.R.Fisher said:

  I want to give more attention to tap tones, modes flexing and so on 

Here's something else I found.  As usual, written by someone else but I thought worthy of keeping......

........ if a plate at a given mode 5 frequency is "x" grams heavier than the ideal weight then you can estimate the correction to it's mode 5 by multiplying the excess weight "x" as follows:  x 32/24 for a belly and x 19/24 for a back.

  Ideal weight 65 gr for belly,  109 gr for back plate.

ex. {a} a heavy belly at 90 gr and 330 hz mode 5.  It's excess weight over the reference weight is 90 - 65 = 25 grams.  Multiplying that number by x 32/24 converts it to hz and gives a mode 5 correction of 33 hz:  so the idealized mode 5 is 330 hz + 33 hz = 363 hz instead of the present 330 hz. 

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10 minutes ago, Don Noon said:

Resource screening factor #1:  is the resource known to consistently produce world-class instruments?

(FWIW, my own opinions are similar to Davide's)

 

            My resource   :CMH       " I have learned that if modes #2 matches in top and in back, than mode #5 can be at the same or different frequencies in top and in back for good results".

                                                                          Some old lady of the by gone days??

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27 minutes ago, David Burgess said:

What the heck is CMH? Is it a reference to the services of the Community Mental Health department?

i believe that's Carleen Maley Hutchins

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Hmmm... to follow CMH advice and (perhaps) attain her results, or go with Davide's advice in an attempt to emulate his results.  

What would you choose?

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10 minutes ago, Don Noon said:

Hmmm... to follow CMH advice and (perhaps) attain her results, or go with Davide's advice in an attempt to emulate his results.  

What would you choose?

 I have great respect  for both but unfortunately   have never had opportunity to hear or play either of their instruments.

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5 hours ago, H.R.Fisher said:

            My resource   :CMH       " I have learned that if modes #2 matches in top and in back, than mode #5 can be at the same or different frequencies in top and in back for good results".

                                                                          Some old lady of the by gone days??

 
I learned a lot thanks to the initial input of Hutchins, whose work I respect a lot, but then I took my path following my work, not that of others of which we never know enough in detail.
For example, what you report from her writings has no meaning without knowing what weight and type of arching we are referring to.

 
2 hours ago, H.R.Fisher said:

 I have great respect  for both but unfortunately   have never had opportunity to hear or play either of their instruments.

I've never heard Hutchins violins either, but what I know is that her systems do not work well with my violins.
It is difficult (almost impossible?) to have data on top and back tap tones ratios of famous violins for obvious reasons, and I do not know on what statistically valid data Hutchins could formulate her theories, but as regards the top some data that at least contradicts his octave tuning theory can be found :

http://josephcurtinstudios.com/wp-content/uploads/2013/09/StradTapTones.pdf

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I wonder if Carleen had a pile of similar well seasoned wood at hand, which could explain her strong statements about the relations between M5/M2 in top/back plates.

The other possibility would be completely delusional

It took three violins for me to understand that what she stated is not possible. I had different wood for all three as I bought wood for them separately from a local music store.

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9 hours ago, Peter K-G said:

I wonder if Carleen had a pile of similar well seasoned wood at hand, which could explain her strong statements about the relations between M5/M2 in top/back plates.

The other possibility would be completely delusional

It took three violins for me to understand that what she stated is not possible. I had different wood for all three as I bought wood for them separately from a local music store.

Carleen certainly thought it was helpful to have a pile of similar wood.  She told me a story where she planned to have a lifetime supply for back plates by having a whole tree of curly maple cut up and stored in the upstairs of a barn her son-in-law had in Vermont.  After a few years to dry the wood she went back to get some only to discover her son-in-law had sold it all to a gun stock  wood supplier for flint lock rifle builders.  She said the only good part of the story was that her daughter had later divorced him.

Carleen had the theory that the M5/M2 ratio should be 2.0 meaning that their frequencies should be an octave apart. But Joseph Curtin found ( see his "Tap Routine" Strad article) that many old Italian plates had M5/M2 ratios of about 2.3 and he made these comments:

"Modes 2 and 5 are of special interest, being most directly related to the stiffness of the plate across and along the grain."

"As mode 2 reflects the cross-grain stiffness of the wood far more than does mode 5, this suggests that the spruce found in old Italian tops may be stiffer along the grain, and/or weaker across it, than new wood."

 

Attached is a graph showing how one of my top's M5/M2 ratio was changing between about 2.0 and 2.4 with each thinning step on the inside surface of the plate.  Obviously the wood isn't changing so the M5/M2 ratio doesn't tell us much about the wood.  I went from new wood to old wood and back again to new wood behavior in 67 easy steps.

Jules' top plate steps.jpg

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Personally, I feel that Hutchins' contribution was that the plate vibrates in modes. Rather than asking which mode a Cremonese maker evaluated, she went off the tracks thinking that she had uncovered something that was better than what the old makers did. Then, plate tuning became numerology.

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1 hour ago, Michael_Molnar said:

Personally, I feel that Hutchins' contribution was that the plate vibrates in modes. Rather than asking which mode a Cremonese maker evaluated, she went off the tracks thinking that she had uncovered something that was better than what the old makers did. Then, plate tuning became numerology.

Another story she told me was about a visit to China to give a talk on plate tuning.  She said something in her presentation and somebody in the audience pointed out that she was contradicting herself because in one of her earlier papers she said something different.  She said yes.  In the past she had said something that was latter proven not to be correct and that she had been wrong earlier.  The Chinese were astounded that she would simply say she was wrong in front of so many people.  

She told me never never to be afraid of admitting you were wrong.  

So if that ever happens with me I'll let you know.

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6 hours ago, Marty Kasprzyk said:

 Joseph Curtin found ( see his "Tap Routine" Strad article) that many old Italian plates had M5/M2 ratios of about 2.3 and he made these comments:

"Modes 2 and 5 are of special interest, being most directly related to the stiffness of the plate across and along the grain."

"As mode 2 reflects the cross-grain stiffness of the wood far more than does mode 5, this suggests that the spruce found in old Italian tops may be stiffer along the grain, and/or weaker across it, than new wood."

 

 

 

If this is indeed the case, how can the cross grain stiffness changes be estimated after 350 years, compared to new wood? Anyone using old Cremona violins as a reference has to always keep in mind that these violins parameters have changed over their life.

Perhaps if a new instrument is plate tuned using a 350 year old plate as a target reference, it may well miss the mark as it ages, ie: In 350 years, the new instrument will more closely resemble an instrument that is maybe 700  years old; However I don't believe these changes through aging follow any linear relationship.

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5 hours ago, Marty Kasprzyk said:

Another story she told me was about a visit to China to give a talk on plate tuning.  She said something in her presentation and somebody in the audience pointed out that she was contradicting herself because in one of her earlier papers she said something different.  She said yes.  In the past she had said something that was latter proven not to be correct and that she had been wrong earlier.  The Chinese were astounded that she would simply say she was wrong in front of so many people.  

She told me never never to be afraid of admitting you were wrong.  

So if that ever happens with me I'll let you know.

She sounds like a real character! You're lucky you got to know her. I would like to have heard some of her stories.

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