Violin data sheet suggestions Options

[catnip]

I am relatively new to violin making (finished #1 and working on
#2).  As I am reading this informative newsgroup I wish I had
taken certain measurements of #1 for future comparison.  For
example, I only measured mode 5 and found that had I also measured
mode 2 I could have calculated a stiffness constant ( weight (gm) *
average frequency mode squared. I have informally documented the
weight of the plates, the garland, the neck and some finished
graduation numbers for the plates.  I plan to make a word
document ( probably two pages worth) where I can just fill in the
data as I am finishing the violin.



Are there other data measurements that are important for future
comparisons?

[Oded Kishony]

Whatever data you collect you can be sure that at some point you will wish you collected some other data :-)


Oded Kishony

[Torbjörn Zetheli...]

quote:

---

Originally posted by: catnipFor
example, I only measured mode 5 and found that had I also measured
mode 2 I could have calculated a stiffness constant ( weight (gm) *
average frequency mode squared.

---

What would this information tell you?

I like to record the weight of the plates, rib garland, scroll, bassbar. Also record the thicknesses in the plates, ribs and linings. The calculation of the bassbar (I like to calculate with geometric formulas). Density of the wood is a good thing to have too. I have more or less stopped recording the modes (1, 2, 5). Don't see the point in doing so?

[catnip]

I have read whatever I could find on plate tuning using the
different modes and I have come to my own early  conclusion
that it is not that important but I have read an interesting
article by Nigel Harris  "On Graduating the Thickness of
Violin Plates to Achieve Tonal Repeatability"  where the
"stiffness"  of violin plate can be measured by multiplying
the weight of the plate (W) times the average frequency (f  of
mode 2 and 5) squared.  

 K= w* f*f

This formula is derived in the appendix of the article based on the
physics of  a deflected beam and the resonant frequency of an
elastic beam of wood. This means to me that if you have
a greater cross arching then you can have thinner plates to
maintain the same "stiffness".  There are some other
statistics that he uses to measure the quality of a
violin. 



As Lord Kelvin said " If you can measure something and express it
in numbers then you can say that you really know something about
it. If you can't measure what you are studying then your knowledge
of it is meager and unsatisfactory"



I have Strobel's book "Useful Measurements for Violin Makers" which
I can use as a starting point but most of those are standard
statistics and a such are the same from one violin to another.



Whereas the finishing of a violin (sealer, ground, varnish, no of
coats etc ) might be different from one violin to another.
 Also the the "quality" of wood can vary.  Maybe if the
wood is not the best quality it needs to be arched differently or
left a bit thicker to maintain the same stiffness.

[Andres Sender]

If you can measure something and express it in numbers you do really know something about that specific property.

The leap from a property to the complexities of a completed sounding violin is rather a large one. Didn't David Burgess just mention in another thread that he has not found a correlation between stiffness measurements and the sound of the instruments?

This is not to argue against recording properties per se, just a warning against leaps. Violin makers have strong legs but must plod, ever plod.

[Melving]

quote:

---

Originally posted by: Oded Kishony Whatever data
you collect you can be sure that at some point you will wish you
collected some other data :-) Oded Kishony

---

................................................................................
.....................................




Hi Catnip

I love Oded's sentiment as quoted above......Your intuition to log
all making experiences is a good one in my opinion.



I keep a paper log book recording all the making I do at the bench.
Paper appeals to me best as it is immediate and my lap top does not
like dust whereas a book is happy to sit on the bench, be written
on and dusted off & a splash of varnish is no bad thing &
to be honest I'm not smart with computers. I try to record
everything I do in making or with any historically significant
restorations etc  I also record my feelings about what I am
doing and how I feel it will work. as foot notes.....I use my
records a lot....often I will turn back the archives for help with
work I am doing now....Looking back it is often the footnotes that
can help the most.........I think a paper diary  of making
might be best......The data base you set up  for No2 will not
answer questions you have for No8

[NewNewbie]

As Lord Kelvin said " If you can measure something and express it
in numbers then you can say that you really know something about
it. If you can't measure what you are studying then your knowledge
of it is meager and unsatisfactory"

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------




I am not against notes, and formulas, just that notes and formulas
can be misleading, in that they can lead the person into
believing that they are holding the key to success.



Violin making is not a Science, not to say that parts of it are
not. So my 'guess' is that Lord Kelvin would probably be
a lousy violin maker.

Plus or minus no, yes or maybe so, give or take a few. Ahuh!

Science is only the endeavour to obtain or find Scientific Truth.
 When you take the whole universe into consideration, that is
a very very small area of exploration, so I would only warn you not
to limit yourself.



Nigel Harris ( and more notable, Martin Schleske amongst others )
are trying to reduplicate instruments based on a 'master
instrument'.  This may not be 'the best' way to take advantage
of any given piece of wood. I would make the goal of trying to
tackle each instrument as a voyage into the unknown, and then try
to get the most out of it.



This is what I would consider to be the best thread a new maker can
follow: it's by Michael Darnton, it's just 123 words, and 4 lines
long, 5 sentences.



"http://www.maestronet.com/forums/messageview.cfm?catid=4&threadid=244465&highlight_key=y&keyword1=weight%20AND%20stiffness">
http://www.maestronet.com/forums/messagevi...AND%20stiffness




You have to take into consideration, that before this modern age of
books, and sharing knowledge, people were trained by other people
that had attained a certain degree of success behind them, and so
when an apprentice started out, he was guided by an experienced
hand. It is pretty hard to make a bad instrument this way, if you
subject yourself to the "Master Maker".  Today we are plagued
with a lot of 'know it all' types that cannot subject themselves to
a "Master Maker".  I would hazard a guess that this is in no
small part due to the modern idea of Science being everything.



So where would these numbers help you is probably getting you on
the road a little quicker, at the start, but I would say that the
final destination, at the end,  is an Unknown Quantity, if you
are not limiting yourself !





Now of course if you discover Stradivari's Secret notes ( forget
Guarneri's as I hear that they are illegible ) then please let me
know, and forget everything that I have said.

Ohh ! And don't call your notes Master Notes!

Now back to work. Ahh ..... now where did I put those
notes!

[Oded Kishony]

Hi,

Like Melvin I also keep paper notes-too many computer crashes and mysterious erasures over the years. I even print out things that I find on line onto paper if I really want to keep them. If something is REALLY important, I imprint it on clay tablets....no...that was a previous life...sorry. ;-)

Oded

[iburkard]

I actually have a very detailed spreadsheet
that covers milligram weight shifts and individual plate
frequency.  I like to keep a close watch on what my violins
eats for dinner.

[violins88]

I make records of not only the free plate frequencies Modes 1,2 and 5, but also in the finished instrument, the A0, T, and B1+ modes. I don't have any conclusions yet. And yes, I studied science, so I feel comfortable with recorded measurements. It is only natural for fine craftsmen to take pride in their ability to use sensitive hands and eyes to create. But for me, I am too close to the K-12 education field. In this field, for a long time, we did NOT measure accurately our students' progress. We probably still don't. But "If you don't know where you are today, how will you know if you have improved next year?"

Not measuring makes it much easier to thump your chest and brag and also debunk the other violinmaker without proof.

I also know educated people (well at least they have letters after their names) who IMHO are just as biased as uneducated people. I will probably delete this post soon. So get it while it's hot.

[Michael_Molnar]

Like violins88 I put that data on a large index card along with weights, sources of wood, varnish procedure, and anything that may be useful later on.

And I agree with her philosophy - You never know where you are going unless you know where you've been.

[iburkard]

" font-family: Arial; font-size: 10.0pt;">There is definitely a
romantic side to violin making that is easily upset when you start
talking about measuring an instrument with a machine. 
Didn’t you ever watch the Red Violin?  The guy running
the plate response tests was clearly a soulless nerd!  :
) 

" font-family: Arial; font-size: 10.0pt;"> 

" font-family: Arial; font-size: 10.0pt;">So you’re gathering
data with the hope that what?

" font-family: Arial; font-size: 10.0pt;"> 

" font-family: Arial; font-size: 10.0pt;">I think it’s great
to have a record of what you did that gave you favorable
results.  People are a little obsessed with the idea of
possibly creating near perfection though… and even more
afraid of being unable to recreate the work a second time (and
compensate by recording way too much data?).

" font-family: Arial; font-size: 10.0pt;"> 

" font-family: Arial; font-size: 10.0pt;">If you spend all of your
time analyzing where you’ve been, you may never go
anywhere.

[violins88]

iburkard wrote: If you spend all of your
time analyzing where you've been, you may never go
anywhere.

Agreed. One must have the energy and guts to actually try something out instead of just thinking about it.

[GMM22]

"I think it's great to have a record of what you did that gave you favorable results. People are a little obsessed with the idea of possibly creating near perfection though... and even more afraid of being unable to recreate the work a second time (and compensate by recording way too much data?)."


I would surmise that all instrument makers can be arbitrarily put into two classes, those who are obsessed with the idea of possibly creating near perfection, and those who are not. I would further surmise that the former win more contests and command more money on average than the latter.

There is nothing wrong with either group, and instrument making can encompass every approach.

[GMM22]

"If you spend all of your time analyzing where you've been, you may never go anywhere."

I think you may have overanalyzed the analysis. I think one could record all that would be relevant for a given violin in perhaps a cumulative hour or two, and this is not a long time.

[Michael_Molnar]

Yes. By all means, do all things in moderation.

I agree with Oded that there is always something new to add to my records. Varnishing was one of them. It's good to now what I did to make a nice looking violin. The older I get, the more important it is to write things down.

BTW, Oded, animal skins are lighter than clay tablets. Oops that is one of my trade secrets. (grins)

[JonathanR]

 

I've found Dr Harris's work enormously useful in
improving the tone of factory fiddles. By matching his plate
'stiffness factors' of their front and back, I've made various
dreadful factory violins sound and play rather well. What seems to
matter is taking the plate’s weight into account in choosing
the tap tones, and then matching the ‘stiffness
factor’ of front and back. What results each time has been a
magnificent G string sound, and a good A string. The D and E string
tones do seem to be pot luck though.  

 

With regard to documenting everything? 
Isn’t reflection on what went right, and most important what
went wrong the basis of all learning?  I now record
(pencil’s good) and photograph most of what I do.
 I’ve so often regretted not measuring or
recording everything, especially on a fiddle that turned real good:
 I don’t know what I did right to make it
good! Details at  "http://www.platetuning.org/">www.platetuning.org.

[DutchViolins]

I read through the given article. This approach of plate tuning as suggested by Dr. Harris may work although I think that improving factory made instruments is easily done without this way of tuning. After detaching a belly from a factory violin it's obvious that in many cases the plate is too thick and has an integrated bass bar with incorrect dimensions and stiffness.
Without using plate tuning one is able to improve the sound of these instruments by adjusting thickness distributions mainly of the belly in combination with a new designed bass bar.

Compared with the articles of Hutchins and Saunders I must admit that the approach of Dr. Harris sounds a little more receptive to me.

At least it's worth to spend an awful sounding cheap factory violin on it!


Frits

[troutabout]

(( As Lord Kelvin said " If you can measure something and express it in numbers then you can say that you really know something about it. If you can't measure what you are studying then your knowledge of it is meager and unsatisfactory" ))

Well, that blows Amati and Stradivari, et al - clean out of the water. No millimeters, no grams. Nothing to measure with except eyes and ears. No numbers other than 'violin number 4' or mastic the weight of a hen's egg.

[GMM22]

I think you are taking the statement out of context. Kelvin clearly did not have violins in mind when he said such. Further, the quote as used by the poster was merely validation of the process of measuring certain violin parameters. There are a multitude of approaches to any craft, and many have merit. If a maker could garner some kind of useful information from measuring the dielectric constant from corner to corner, so be it. If another nets good violins from working in candlelight, well there you go. Besides, what do we really know about what Stradivari or Amati observed and noted during the making process.