Violin Forum/Message Board

[terryc]

Hello all,
Need some advice, or maybe some comfort with respect to how far to go with graduating the back plate to get down to a reasonable weight & thickness. I have spent hours of research on the subject and from all info gathered, the plate is still too stiff and I think approaching the limits on thickness.

This is my first attempt at building a violin and never been in this territory before. The weight is currently 116.5 grams with edge work completed. I do have about an extra 1/4 inch of stock for the button.

I am using a bulleye pattern generally, with center at 4-4.5mm, moving out, with the thickness decreasing gradually to 2.5-2.8mm in the larger sections of the upper and lower bouts.

Thanks
Terryc

[Michael Darnton]

That's fine. Time to move on.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[Chet Bishop]

On what basis are you saying that the plate is too stiff, Terry? Twisting it in your hands? tap tones? Something else? Just curious...

Thickness measurement and physical twisting, bending, tapping, etc. is all I use, but then I'm no expert, by any stretch.

I could never get the Chladni patterns, etc. to work well for me, and I finally took note that most of the really well-established makers don't use it, so I decided to let it go. On the other hand, there are plenty who do-- I am not criticizing. I just never got good enough at it to make it a reasonable part of the process for me.
_________________
Chet Bishop
https://bluefiddles.com
https://fivestringfiddles.com

[terryc]

Michael,
Thanks
Terryc

[terryc]

Chet,
Thanks so much for getting back. My basis of stiffness in the back plate is mostly the feel but admittedly I have no real experience to judge. So, have gravitated to more quantitative approach in using Chladni patterns which have produced fairly defined Mode 5 & 2 patterns, at 407Hz / 185Hz respectively.

These translate into stiff plates using some of the research done by others.
http://www.platetuning.org/html/tone_and_weights.html
At issue here is, they appear quite a bit out of the generally excepted range of 300Hz and 370Hz, (F and F#). As noted earlier, the weight is 116.5 grams (versus an average weight of say 96 - 110 grams) with edge work completed and excess 1/4" stock on the button.

I am using a bulleye pattern generally, with center at 4-4.5mm, moving out, with the thickness decreasing gradually to 2.5-2.8mm in the larger sections of the upper and lower bouts. Just do not want to go too far with the thinning.
Have tried tap tuning using Audacity and Overtone Analyzer but have trouble identifying the resonant frequency versus other harmonics on a consistent basis.

Chet, thanks again for your interest and input.
terryc

[kjb]

from what I have learned the exact weight and hz can vary for the density and stiffness of the wood, I don't think you are out of the ballpark with those numbers, I am working on one now that is not working out to the numbers at all 121 grams, and low numbers, I wish my numbers were as good as yours. I will put it together at some point and see just how it sounds, and I guess that is the experience that is gained, just keep notes so you know what you did. good luck

[terryc]

kjb,
Thanks for the encouragement! Lots of fun and many questions along the way.

What is your plate thickness range? And are you using Chladni patterns and if so, whats the resonance frequency? I find this stuff fascinating. How far along are you? When do you expect to test it out?
Thanks
terryc

[Michael Darnton]

Whoosh! Another one down the rabbit hole!

Terry, here's a question for you: what, specifically, are you hoping to accomplish with tuning, as clearly as you can express it?

In the range of Strads and del Gesus I have personally measured, back thicknesses in the center vary between 3.2 and 6.3mm (generally about twice in the center as the minimums in the upper and lower bouts), and total strung up weights, minus chinrest, run from 360gms to 420gms. This is on fully functional, desirable instruments in everyday use by famous players. The work that has been done on virtually all violins of this type over the past 300 years, and the consequential changes, totally rules out the possibility that there is any bit of any original tuning (had there been any in the first place) remaining. Additionally, many of these genuinely great instruments were very obviously entirely regraduated by someone later on. So if your objective is to replicate the behavior of the best instruments of the past, tuning anything is not a logical direction to go in, inasmuch as it contributes absolutely nothing to the behavior of these, the greatest, violins.

Given this, I am understanding that your intention is not to recreate this type of instrument, so what's your target regarding behavior and tonality?
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[Michael Darnton]

Here's an example of what I mean: when I talk with teachers, I find that many of them use carbon bows for teaching. They tell me that the advantage of doing this is that while a wooden bow may be better, a carbon one acts exactly the same every time, which makes demonstrating to students easier.

What I see happening is that many modern makers take this approach to building: they build a violin that sounds the same, some one definition of "good", no matter how it's played. This is very appealing for a player with minimal control, in that they sound "good" all the time, and there are no surprises, but it's a deficit for a great player who wants to do widely varying things with his instrument. Not coincidentally, you see a lot of these "good" instruments in the hands of younger players, and (see above) teachers.

The trick here is to avoid listening to the advertising pitches (EVERYONE who's making violins claims to work in the "Cremonese Tradition" delivers "Artist's Instruments", and advertises he's a "Tonal Expert"), and see what is actually being delivered, and to whom: the bulk of customers in the new violin, $10,000 to $30,000 range, are relative beginners--conservatory students and beginning orchestra players, not great professional artists, and their needs are different. The bulk of the great artists aren't playing that type of one-track instrument and haven't ever done so in any meaningful numbers. . . but they aren't buying many new violins, either, so they're not a real market force for new makers.

If that's where you want to be making, where the money is, and that is indeed where the money is, tuning--forcing a violin to vibrate only in certain ways--is one of the various things that will help you get there.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[kjb]

thanks for that explanation, makes a lot of sense.

[kjb]

I was thinking about it today, and for me the problem is trying to get some measurable idea of what you are trying to do.

the plate tuning is something that you can measure so that makes it somewhat easier to mentalize what is going on with the wood. You can make the patterns you can measure the frequency and the weight, it solid evidence of something. But is does not make a great instrument, otherwise we could just mechanize it all and that would be the end of it.

the flexing of the plates is something that you can't explain, I think you would have to be shown a number of times on different plates. and probably over a period of tiem.
The intuition I guess which is something I don't think is explainable or measurable, you just have to do it and learn it.

we all want to have some result that we are happy with, but nothing we do starts out with a great outcome every time and sometimes it never happens, but I guess hope springs eternal, and I guess it is natural to hope for the golden bullet or the epiphany that will let you see the light,
I think in the case of violins, and lots of other stuff, you need lots of those to get somewhere
A lot of us on these web sites probably will make less than a hundred and a lot will make less than 50, 20 or less, probably we will never
get to those levels of understanding, but the enjoyment is in the doing.


as to your remark about different types of instruments, at the last VSA a very good swing player was trying out an instrument that was not considered a "classic sounding" but he was in love with it.
It suited his style much better than any he had played.

well maybe I thought too much!! boca grande award!

[John Schmidt]

Terry,

I can help you use Audacity to easily find M5 the main mode of the top and back plates. Email would be preferable.

John

[actonern]

Michael, you say above that some golden period instruments have "obviously" been re-graduated.

I'm interested in knowing a bit more about the "tells" inside instruments that show us this has happened. After many decades of dirt and dust has accumulated following re-grad work, how easy is it to detect?

E

[Michael Darnton]

There's a whole spectrum of "tells" on this. First, when this was commonly done there wasn't the imperative to cover it up, because the people who did it were proud of their "improving", as one early 1900s shop called it. So you find regraduated areas that are very obviously cleaner, with an entirely different color and texture.

Other signs are quirky grads that aren't typical of the maker, and clockwork-like measurements to the tenth of a mm that weren't even possible in the time these instruments were made, but are sometimes seen, nevertheless.

One well-respected old instrument I worked on required a new bar, and when I took out the old one it was sitting on a platform--someone working on it subsequent to the most recent bar had simply regraduated around the bar, removing about .5mm from the top thickness. That had been done in recent times, and the vandal had tried to otherwise cover up what he'd done with dirt and color.
_________________
new blog at my site! http://darntonviolins.com/blog
my work sites: http://darntonviolins.com and http://darntonhersh.com

[Michael Darnton]