sacconi plateu

[Craig Tucker]

When it comes to Sheep shearers on this forum , there's Lyle and me (20 yrs ago) ...any others?

That's one damn fine looking sheep.

[Janito]

Personally - I don't usually feel that the back (of maple) needs a plateau, but yes, I will leave at least some up to a complete plateau around both the top and bottom block area, for many top plates. (for particulars see page 2, reply #33 - this thread)

Thanks - I did read post #33, but had a temporary memory lapse.

Your final diagram is also what the Mittenwald alumni do.

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Karl Roy's book does not get mentioned often, but the 'making half' is full of fascinating tidbits for makers. If it were to be sold separately, it would be a worthy counterpoint to the Newark way of Courtnall and Johnson.

[NewNewbie]

Is it possible to get back off topic, or is it just too late? :huh:

Oh I see that we have already done that.

Perhaps it would be better if we had a different colour for all the "Off Topic" stuff, so that it can be easily ignored!

I suggest a nice brownish khaki might Be Singularly preferred. :blink:

[dvsutton]

Maybe we should be asking whether anyone has seen top plates that do not have the plateau that are wickedly deformed?

[Salve Håkedal]

When it comes to Sheep shearers on this forum , there's Lyle and me (20 yrs ago) ...any others?

What about goats? Flatfot and me (30 yrs ago).

Regarding the plateu: I use it, if the arching is not too sheep.. ehh, I mean steep.

Which is only if I make copies.

[JohnCockburn]

When it comes to Sheep shearers on this forum , there's Lyle and me (20 yrs ago) ...any others?

What's the function of the men in the white coats?

[NewNewbie]

What's the function of the men in the white coats?

5 words ..... 1 for each digit!

Turn

your

head

and

cough!

Shhhish! I was really surprised that you, John, out of all the people here at Maestronet, oh and sheep, would ask that question!

Just to be on the safe side, if you see this guy, run for the hills!

Alright who's next!

Don't be shy! Come on now. Who's gonna be brave now and ask another question!

No takers? Alright then .....

And now for something completely different ..... Shall we try, say getting back on topic? :blink:

[Anders Buen]

When it comes to Sheep shearers on this forum , there's Lyle and me (20 yrs ago) ...any others?

How much time did you need to do the job? - Less than a minute?

I've never tried, but remember they did cut the wool at home while I was a kid. Not many sheep there, so the speed was not an issue. - Good for the sheep.

[JimMurphy]

Don't be shy! Come on now. Who's gonna be brave now and ask another question!

And now for something completely different ..... Shall we try, say getting back on topic?

Can sheep be fun?

One inviting look and you're ready to go

Nothing like getting your mojo rising

Followed by the inevitable plateau

There now, right back on topic ...

Jim

[JimMurphy]

... Yes a Maggini arch would tend to rise faster...Taking a look at recent pics posted here and on Tarisio of the lady Blunt Strad near the neck under the board can be useful...The shot below is another Strad..the arch is not really taking off until it clears the block

Interestingly, Roger Hargrave wrote an article on Stradivari's Gibson Viola where he comments, "As may be derived from the drawings the arching of the belly rises steeply under the fingerboard and tailpiece, becoming relatively flat along the top." He includes an illustration based on Sacconi's thicknesses for belly & back suggesting The Gibson also has plateaus.

Jim

[Melvin Goldsmith]

What's the function of the men in the white coats?

John, they are always with me.

Well..Actually it was a sheep shearing competition in front of a big audience at the Suffolk county show and they were the judges assessing my technique. IIRC I managed to score 14th place not bad until I have to admit that was from a field of 14 competitors...All was going well until that picture which showed the sheep deciding not to co-operate I'd picked the only sheep with a mind of it's own in the stock pen....at least the audience had a good laugh

[Craig Tucker]

Maybe we should be asking whether anyone has seen top plates that do not have the plateau that are wickedly deformed?

How about just deformed?, no need for "wickedly deformed".

It would be my absolute pleasure to consider any alternative theories or reasons for a plateau.

[JimMurphy]

It would be my absolute pleasure to consider any alternative theories or reasons for a plateau.

This is more of a 'question' than a theory or reason:

Way back when bowed string instrument bassbars were shorter AND integrally carved into the belly, were plateaus used??

Thanks,

Jim

[Craig Tucker]

This is more of a 'question' than a theory or reason:

Perhaps.

I suppose that depends on whether or not one is looking for a reason or a theory behind the question of why would someone use a plateau like this, right there at that position?

What would be the advantage?

Would it be an attempt to remedy something, or an attempt to further tailor or alter the tonal value towards what we seek?

I don't think that many things having to do with Cremonese instruments (in particular, those things in connection with the plates, arching, thickness, and the rest) were left to chance, or to the toss of a coin.

Way back when bowed string instrument bassbars were shorter AND integrally carved into the belly, were plateaus used??

Thanks,

Jim

Part of my question has to do with the actual presence of this trait, historically. How often can we see it as an artifact in traditional instruments? Mr. Darnton mentions seeing one in existence on an original Strad plate - so, I will assume that they did exist, at least at times on some Cremonese plates. On the other hand, I have to wonder if we'd even be having this discussion, without Sacconi's book?

[JimMurphy]

I suppose that depends on whether or not one is looking for a reason or a theory behind the question of why would someone use a plateau like this, right there at that position? ... I don't think that many things having to do with Cremonese instruments (in particular, those things in connection with the plates, arching, thickness, and the rest) were left to chance, or to the toss of a coin.

I get the impression many here firmly believe even the Cremonese Masters weren't immune from applying 'empirical' methods to Violin.

That said, it's very possible plateaus were simply a carry-over from earlier Viol, Viola da gamba, etc. construction. I simply dunno for sure. Some Cremonese instruments have plateaus even though they changed their bassbar design.

Jim

[Anders Buen]

Perhaps.

I suppose that depends on whether or not one is looking for a reason or a theory behind the question of why would someone use a plateau like this, right there at that position?

What would be the advantage?

Would it be an attempt to remedy something, or an attempt to further tailor or alter the tonal value towards what we seek?

I don't think that many things having to do with Cremonese instruments (in particular, those things in connection with the plates, arching, thickness, and the rest) were left to chance, or to the toss of a coin.

I guess you know this just as well as anybody. The end block regions are difficult to deal with when opening an instrument, especially so the upper block region with the fingerboard in place. Cracks easily develop at each side of the neck in the top plate or to each side of the tailpice nut (or whatever). A thicker region to each side of the block should make the plate more safe against cracks there, at least for us "quickies" when the plates are taken off. (A restorer on an expencive violin can spend hours, if not a day, opening a violin).

I think one of the "big names among the acoustics workshop makers" suggested that this may be a crack prevention plateu.

Regarding plate end strength: My grandpa used a very short and low bassbar (20-21cm, 7mm ish high, and almost even height all the way) and added wood to the end region of the plates instead. Not really a plateu, but just more "beef" there. Not so interesting to most readers here, but some of his regraduations are "world class" Hardanger fiddles. The plates are often reverse greaduated, exaggerated by the thicker end regions, and the lungs are sometimes below 1,5mm. Stiff and probably somewhat dense wood, plus the relatively low humidity here helps the statics to work. It may also help the sometimes very high tuned fiddles to stay better in tune I think, and possibly pushing the modes up a little.

Oliver Rodgers FEA analyses on violin plates on ribs indicate that the block regions are regions of high sensitivity for the "plate on the ribs modes". A bit "fishy" with the artificially stiff ribs and thus not quite natural mode shapes, I think. (Natural boundary conditions is a problem in FEA on rib attached violin plates). But may be interesting to investigate a bit further.

I am waiting for some experimental violins in the white now from China, so this issue may be a possible one to work on over the summer.

[JimMurphy]

Looks like Johann Reiter [Mittenwald, Germany] had been reading Sacconi too [see the plateaus]:

[NewNewbie]

Ran into at Jim McKean's blog his posts on the Sacconi Plateau.

Part 19

"Once again, it’s that balance: you need flexibility for richness of sound, but you also need rigidity, for support and stability – in this case, to temper the wolf.

That’s why the upper and lower blocks are the size and shape they are. The depth of the block means that the wood of the top or back is much thicker in that area of greatest flexibility:" - from above link

"This is a detail of a drawing from that same earlier posting (pt.13). It shows in cross-section the thickness of the top and back -- and you can see how they widen as they drop down to meet the block area. At the violinmaking school we used the German method, which called for deeper and narrower blocks (like the French). When we got the Sacconi book on Strad, just published at that time, we were surprised at how shallow and wide the blocks were, and thought it must be a mistake. That is exactly the reasoning that lead the violinmakers of the 19th century – those German and French makers – to abandon such design aspects as the long saddle on the top arch (wow, here's a surprise -- pt. 13 again) – they also thought that must be a mistake. However, I have gradually come to realize why those blocks are the size and shape they are, and how they perfectly balance flexibility and support. By making the block so much wider, they enormously strengthen the top in particular against stress cracks at the ends by distributing the load; and doing it in a way that does not impede vibration. In some ways that extra width is like the flying buttresses on Gothic cathedrals; not a perfect analogy, of course, but it does give some idea of what it does." - from above link

"If you graduate that area on each side of the block, you’re just asking for end cracks by the side of the neck or the ebony saddle at the lower end; and you’re not getting anything in greater vibration of the top. Good vibration, that is (thank you Brian) – in fact, it seems as though all you’re doing is adding to the wolf. Of course, the question then comes up, why feather it? If there is any cardinal rule of the great Italian makers we are trying to emulate, it’s that every extra stroke of the tool is time lost. And time lost is time wasted." - from above link

Making a new cello: Part 13 -- How it works

Should point out that he is at part 4 of making a viola right now.

Thank You Jim McKean!!!

Jim McKean's Blog

[David Burgess]

Jim's an experienced writer, who's written quite a bit for Strings Magazine, and I think has at least one novel under his belt.

The engineers here may have some questions about his assertions, reasoning and conclusions. I would have the same questions, and add some about how he arrived at the thought processes of historical makers, like, "That is exactly the reasoning that lead the violinmakers of the 19th century – those German and French makers – to abandon such design aspects as the long saddle on the top arch (wow, here's a surprise -- pt. 13 again) – they also thought that must be a mistake."

Did he interview these makers, or what?

[James M. Jones]

Did he interview these makers, or what?

he said something to the effect "From what I've read" I didn't see any citations . nice read though. thanks Newbee.

[Roger Hargrave]

Are we seeing just another 'working method' clue left behind for the inside arching first approach, that only makes sense since violins perform well with and without the Sacconi Platform.

This is the right approach to such questions. My feeling is that a certain stiffness here would not go amiss. I am keen on stiffness for sound, especially around the edges. The opposite in fact of a loudspeaker which is sprung or feathered around the edges. All well preserved classical instruments are stiff/strong in these areas. These platforms might also help to prevent the end areas especially the neck area from twisting slightly to the side when the instrument is under playing tension. However, as always with instrument making the simplest practical explanation may be the best. Ethereal explanations should be left to the Gods. But for the simple practical explanations we need to place ourselves into their shoes. Someone recently put super pictures of the Cremonese closing cramps on this site (somewhere). If any one has them, perhaps someone could also put pictures of the Cremonese metal clamps up here as well, so that we can really grasp the idea of their limitations, and their potential for inflicting collateral damage. If we then think about how these plates were worked, ie from the outside first, (sorry Torbjörn Zethelius), then we can see that at the point of hollowing the plates the outside edges were still square and flat. They were kept flat, mainly because of these aforementioned clamps and the clamping process as the instrument was being closed. If we then assume that the plates were held in some way for the hollowing process then it would have been helpful to have a flat area running across both ends to aid clamping during this hollowing process.

In effect, before the purfling channel was hollowed, this platform would have created a very substantial and stable block of wood at either end of the plates. As NewNewbie puts it, "just another 'working method' clue left behind..."

[Addie]

I thought Stainer's plates were quite thin around the edges? Is that just the sides, and not the ends (where a plateau would go)? Is this an endgrain issue?

Thanks!

[Don Noon]

My feeling is that a certain stiffness here would not go amiss. I am keen on stiffness for sound, especially around the edges. The opposite in fact of a loudspeaker which is sprung or feathered around the edges. All well preserved classical instruments are stiff/strong in these areas.

There is a natural tendency (which I am gradually overcoming) to think of violin plates as loudspeaker cones... which they are not. One look at the Strad3D animations will show that immediately. At Oberlin this year, Evan Davis showed some theoretical modelling of surface radiators that indicated higher acoustic radiation efficiency for stiff edges vs. soft edges.

[LinkMan]

But for the simple practical explanations we need to place ourselves into their shoes. Someone recently put super pictures of the Cremonese closing cramps on this site (somewhere). If any one has them, perhaps someone could also put pictures of the Cremonese metal clamps up here as well, so that we can really grasp the idea of their limitations, and their potential for inflicting collateral damage.

National Music Museum, NMM

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StradivariusTools @ www.kevinleeluthier.com

[Roger Hargrave]

Beautiful! Thanks!