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Beckham could try American football just for fun...

Is it not illusory anyway to blindly follow any graduation map of an instrument when making another one since the wood properties will be very different ?

Seems like it would be illusory. But is it not reasonable to follow the same strategy ( poster graduation vs Sacconi) and then individualize the thickness for each plate based on weight, taps tones or whatever else is used?

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Well yes, I guess this is what being a violin maker is really about. Finding a way, more or less personal way, of making the most of each plate with some general graduation schemes to start with before optimising.

As for measuring the thickness of plates I am quite certain that the same plate measured by 2 different persons on 2 different days with the same thickness gauge will show some variations of at least 0.1mm unless they are absolutely certain they placed the gauge at the same exact spot. Average maps (like the one I got from the back of Guarneri violins) seem to me of more immediate application (it would have been good to get the standard error too).

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Not so long ago I made a pastiche of a late del Gesu. It was based on the Leduc but I made the back at least as thick as the Cannone del Gesu if not thicker. This was inspired by a visit to a top bespoke hi fi company and discussing the construction of their speaker cabinets. It was an experiment but to my satisfaction the violin back had the acoustic properties of a bread board. As in most of my work I expected to do some refining and very likely radical re thicknessing of this back once the violin was completed. To my surprise the violin worked very well for the right player and was last seen in the hands of a top session player....

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All of my del gesu models for the last ten years have had backs over 6mm, as thick as 6.7mm, and they are fine to play. I blame their good qualities on the careful archings I use, permitting not a bit of easy response lost. What is gained is a much broader power curve.

Could you post some thickness maps? After all it can be measured so it is not proprietary.

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It's a story that appeals to some people but falls apart on close examination of the real violins. I think the regraduation theme has been overplayed by people with a particular axe to grind: that old violins are damaged wrecks and don't work (contrary to all playing evidence, apparently, but nevermind that). You can find that theme actively advanced here, if you can get past all of the typography (bright red, bolding, underlining hysterics) that's so typical of crackpot publishing: http://www.fritz-reuter.com/ After that, you can go check the intellectual equivalent in physics here: http://timecube.com/

Relative to regrads on Strads, it appears the his thicknesses were originally thinner in many cases than later makers' work, so you have to ask who would regrad something they already felt was too thin, and I can only think of a couple of examples that I've seen which appeared to have been thinned, but I'm sure there are more. All of these were instruments that didn't work well, and that might have seemed like an excuse for someone to go in and take out some wood to see if it made them better.

Most Strads are consistent with the ones of similar type and period, which tends to indicate to me that they mostly weren't touched. Many del Gesus do appear to have been regraduated, but many haven't, or if they did, they started REALLY thick and then were regraduated all by the same person, with the same thickness goals. :-) Exactly which ones used to be thicker seem to me to be a certain type, many of them relegated to being collector's instruments, so the same inspiration as for Strads might have lead to their being thinned in some cases.

There's a lot of discussion that could go on around this topic; for instance, if they have all been regraduated, and tuning is so very important, who's the genius who regraduated and tuned them? :-) Go down the conspiracy theory paths too far, and you really have to abandon logic to continue.

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Could you post some thickness maps? After all it can be measured so it is not proprietary.

It's not map-worthy. Basically, around 6.2-6.5mm in the center of the narrowest spot of the back tapering off to half that in the upper and lower bouts. The tops, maybe 3.5. All of the numbers plus or minus about .5mm, since I don't use calipers. I mark with my StradPunch, and work very casually. There's no magic in graduation, in my opinion, except that precision is a definite negative: if the industrial revolution hadn't given us calipers, no one would give the issue a thought, but as it is, any idiot can use them and feel like he's being "precise". Arching is a more serious problem, and harder to express in decimals, so it didn't get as much attention until recently. Many people still think they do well enough by eye.

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Well yes, I guess this is what being a violin maker is really about. Finding a way, more or less personal way, of making the most of each plate with some general graduation schemes to start with before optimising.

As for measuring the thickness of plates I am quite certain that the same plate measured by 2 different persons on 2 different days with the same thickness gauge will show some variations of at least 0.1mm unless they are absolutely certain they placed the gauge at the same exact spot. Average maps (like the one I got from the back of Guarneri violins) seem to me of more immediate application (it would have been good to get the standard error too).

Maybe they should be reported with a range, like other data (3 +- 0.1 mm for example).

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It's not map-worthy. Basically, around 6.2-6.5mm in the center of the narrowest spot of the back tapering off to half that in the upper and lower bouts. The tops, maybe 3.5. All of the numbers plus or minus about .5mm, since I don't use calipers. I mark with my StradPunch, and work very casually. There's no magic in graduation, in my opinion, except that precision is a definite negative: if the industrial revolution hadn't given us calipers, no one would give the issue a thought, but as it is, any idiot can use them and feel like he's being "precise". Arching is a more serious problem, and harder to express in decimals, so it didn't get as much attention until recently. Many people still think they do well enough by eye.

Thanks for the info. I always enjoy your insights and openness. I have seen your stradpunch on your site. A top of the 3.5 throughout is beefy indeed as the are the back thicknesses.

Do you follow del gesu archings for a given model (corrected for distortion) or do you vary to your own taste? I have read that you do not subscribe to varying arch too suit the wood characteristcs.

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Many people still think they do well enough by eye.

And some of them probably do.

I need to measure things which other makers can see by eye, and other makers need to measure things I can see by eye.

I can't run a four-minute mile, but I'm still willing to reluctantly entertain the notion that others can. :)

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