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Violin #5 - Strad Body modes


Peter K-G

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To recognize a good sound, you have to have played instruments by Strad and DG; to learn to reproduce it, you have to conduct research. I have done both. 

www.kreitpatrick.com

 

Lots of people have done both, and still falied to produce impressive results.

 

How is one to differentiate between your claims, and all the other claims which have come down the pike over that last 250 years?

 

The proof is in the pudding. I offered that if you would send a violin, I'd pay shipping, and run it by some good players to get their feedback, but you haven't taken me up on it so far.

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Mr. Kreit, I have played a few dozen Strads and Del Gesus, and I have hacklingered and researched and striven to understand; to get inside the methods of these great makers. I have been humbled almost every time, shocked again, that I had forgotten the difference between a Cremonese and what I normally work with.

I don't have any problem with your system; your conclusions you have drawn, even not knowing what they are. I have yet to see your book; I look forward to perusing it.

I just itch every time you announce empirically that you've Solved It! That your year of 20 Betts has ended the conversation.

I think a major theme in this work we do (I don't place myself in your league, by any means), is that polarizing methods to The Answer, and Not The Answer, is just silly.

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David Burgess, on 30 Mar 2013 - 22:14, said:

OK, we do too. But our most significant sharing takes place when makers are gathered together with examples in hand.

I believe you.

I'm also a believer :)

There is nothing better than gathering together and sharing experience, with guidance from a master.

This is not possible for all of us. Next best thing is guidance via books, forums and correspondence via e-mail with a master.

With todays technology we share texts, pictures, sounds and videos. This is opening up possibilities that we people are not fully mastering yet. Face to face discussions usually involve more respect and kindness.

I will try more and more to adjust my posts in that direction. I'm that kind of person in real life.

Happy Easter

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I made the right choice to replace the first back plate Wood!

http://www.maestronet.com/forum/index.php?/topic/327921-violin-5-strad-body-modes/#entry576863

 

It's very likely that this back has speed of sound near 5000 m/s.

After preliminary shaping of the back plate, it registers very high performance capacities (above the values in table 12), this taking into account that the wood MC% is ~1%

 

I think I will be able to achieve the target, 95 g for finished plate with M5, 345 Hz (MC% 6%)

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While C = 5000 m/s for maple would be unusually high, and maybe it would allow you to get a lighter back plate, there's no support for the idea that it is a good thing.  The issue is balance.  If more was better, you'd have phenomenal sounding violins made with spruce back plates.  You could also get lighter plates with the target M5 frequency by thinning the center... which the Old Guys didn't seem to do. 

 

It is my guess that a high-performance back plate will give greater output in the range where the back is most active, i.e. the transition hill frequencies.  That would give more loudness and power, but a less refined tone.  Again, the issue is balance, and what you want out of it.

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Hi Peter:

 

Just a thought about purfling, which you may find useful.  I read some years ago in the Strad magazine an article by some prominent maker (can't remember his name) who described his purfling technique.

 

One of the things he did, after the purfling was glued in place, was run a bead of glue over the installed purfling again.  It was actually a little "bubble" over top of the purfling line, applied with a small brush.  This was then allowed to dry down, with an important benefit.  The glue would seep into any cracks or small faults in the groove, and, in the act of drying, pull everything more closely together.  The result was less gaps.

 

And he also emphasized this... the glue that was applied in this way must not be allowed to dry completely... it becomes so hard that the act of removing it can pull up little splinters of wood.  Instead, get the remaining glue and whatever is proud of the plate removed after about 2 hours and it cleans up very easily.

 

I tried this and it works very well.


Best regards,


E

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Hi Peter:

 

Just a thought about purfling, which you may find useful.  I read some years ago in the Strad magazine an article by some prominent maker (can't remember his name) who described his purfling technique.

 

One of the things he did, after the purfling was glued in place, was run a bead of glue over the installed purfling again.  It was actually a little "bubble" over top of the purfling line, applied with a small brush.  This was then allowed to dry down, with an important benefit.  The glue would seep into any cracks or small faults in the groove, and, in the act of drying, pull everything more closely together.  The result was less gaps.

 

And he also emphasized this... the glue that was applied in this way must not be allowed to dry completely... it becomes so hard that the act of removing it can pull up little splinters of wood.  Instead, get the remaining glue and whatever is proud of the plate removed after about 2 hours and it cleans up very easily.

 

I tried this and it works very well.

Best regards,

E

 

Thanks for the advice!

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While C = 5000 m/s for maple would be unusually high, and maybe it would allow you to get a lighter back plate, there's no support for the idea that it is a good thing.  The issue is balance.  If more was better, you'd have phenomenal sounding violins made with spruce back plates.  You could also get lighter plates with the target M5 frequency by thinning the center... which the Old Guys didn't seem to do. 

 

It is my guess that a high-performance back plate will give greater output in the range where the back is most active, i.e. the transition hill frequencies.  That would give more loudness and power, but a less refined tone.  Again, the issue is balance, and what you want out of it.

 

 

The mode tuning formula worked perfectly as described in Patrick's book with violin #4 (arching, weight and graduation) This was with less performance back plate wood (one piece). For this violin I chose the best high-performance wood I could find. I'm very exited to see how it goes.

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I made the right choice to replace the first back plate Wood!

http://www.maestronet.com/forum/index.php?/topic/327921-violin-5-strad-body-modes/#entry576863

 

It's very likely that this back has speed of sound near 5000 m/s.

After preliminary shaping of the back plate, it registers very high performance capacities (above the values in table 12), this taking into account that the wood MC% is ~1%

 

I think I will be able to achieve the target, 95 g for finished plate with M5, 345 Hz (MC% 6%)

No, not that high soundspeed with those flames!
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No, not that high soundspeed with those flames!

 

I can't tell because I don't have a lucchi meter. Don's method showed around 5000 (so did also the neck piece from the same wood)

I'm following bending mode frequency (M5). After preliminary shaping the frequency was ~30 Hz above the guidelines in table 12. MC% is ~1%.

 

The speed of sound is actully not important for successful tuning, Its much simpler . It's only of pure interest that I'm testing measuring speed of sound.

 

Efter making this violin I think I could make violins this way, without help from technology or caliper. The beuty is that only eyes, ears and fingers are needed, It's very simple but difficult to master.

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While C = 5000 m/s for maple would be unusually high, and maybe it would allow you to get a lighter back plate, there's no support for the idea that it is a good thing.  The issue is balance.  If more was better, you'd have phenomenal sounding violins made with spruce back plates.  You could also get lighter plates with the target M5 frequency by thinning the center... which the Old Guys didn't seem to do. 

 

It is my guess that a high-performance back plate will give greater output in the range where the back is most active, i.e. the transition hill frequencies.  That would give more loudness and power, but a less refined tone.  Again, the issue is balance, and what you want out of it.

Yes, but I've never heard of a bad sounding violin made with a spruce back plate.  All bad violins use maple backs so maybe maple isn't so good.

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Extrados tuned!  I almost managed to tune to the limits :)

Arch height is 14,5 mm and balanced at 192 mm from upper edge.

 

I didn't use templates or any contour gauge, only measured purfling channel (~3,2 mm upper/lower bouts, 3,4 mm C bouts) and height at 192 mm from upper end.

 

post-37356-0-44793700-1365259018_thumb.jpg 

post-37356-0-62887400-1365259072_thumb.jpg

post-37356-0-00350200-1365259117_thumb.jpg 

 

One interesting thing is that the tuning method produces the STL (Straight Tangent Lines) described on http://www.zuger.se

If I'm right they will automatically have a wider angle on the top arching.

 

post-37356-0-34708300-1365259544_thumb.jpg

 

 

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Correction to STL. Due to  small deformation, edges rising up, the first STL:s  where drawn in the wrong place. Pushing down the edges gives new STL:s (the angles might actually be even wider if continuing the lines through the plate with enpoint at where the ribs start)

 

post-37356-0-22406300-1365330628_thumb.jpg

 

They are not in any way necessary for the tuning procedure, but it's of interest to see how the arching turns out:

It's also a good way to monitor arching symmetry!

 

 

 

 

 

 

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Extrados tuned!  I almost managed to tune to the limits :)

Arch height is 14,5 mm and balanced at 192 mm from upper edge.

 

I didn't use templates or any contour gauge, only measured purfling channel (~3,2 mm upper/lower bouts, 3,4 mm C bouts) and height at 192 mm from upper end.

 

attachicon.gifBack_arch_tuned_2.jpg

attachicon.gifBack_arch_tuned_1.jpg

attachicon.gifBack_arch_tuned_3.jpg

 

One interesting thing is that the tuning method produces the STL (Straight Tangent Lines) described on http://www.zuger.se

If I'm right they will automatically have a wider angle on the top arching.

 

attachicon.gifBack_arch_tuned_StraightTangentLine.jpg

That Straight Line Tangent idea is very interesting. Either it makes perfect engineering sense, or it is impossible to make a violin meet that shape.  It akes sense to mme that the compressive and tension forces would transmit best along straight lines.

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There was a thread on this guy's theories recently: http://www.maestronet.com/forum/index.php?/topic/323424-original-theory-on-archings/

 

It makes no engineering sense whatsoever.  That doesn't mean you would end up with a bad instrument if you follow the instructions, but it might.   It certainly is not a prescription for greatness.

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It is not wise to work with plates at 0% MC (I have been warned). Target not acheived.

Backplate is 110 g and M5 is 345 at ~ 2% MC (taget 95 g)

Soundpost area 5,5 mm. It has graduation more like DGs with thicker plateau 4,5-5 mm in middle region.

I have done som very interesting observations though and understand quite well the coupling between tuning, arching and weight.

I'm starting working on the top and parallel with violin #6 at the same time with similar wood.

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That Straight Line Tangent idea is very interesting. Either it makes perfect engineering sense, or it is impossible to make a violin meet that shape.  It akes sense to mme that the compressive and tension forces would transmit best along straight lines.

I think it makes perfectly sense. Both violin #4 and the backplate of this one has theese lines, both tuned and arching is very beautyful.

Checked violin #3 (arching with templates,not tuned) it does not have the STL:s. I think I can see STL:s also from pictures of Titian back from Strad 3D.

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Yesterday I posted in The weigh of back plate:

http://www.maestronet.com/forum/index.php?/topic/328263-the-weigh-of-the-back-plate/#entry583152

 

Haven't had the time to start with top plate. Instead I started wonder if it would be possible to somehow correct the too low and flat arch. At the same time I started looking at the corners bending up after arching. The back plate is 110 g, M5=345 Hz and M2=200 Hz

 

What if  a sponge, steam cleaner and a hair dryer could.....

 

post-37356-0-34468800-1366136994_thumb.jpg

 

post-37356-0-35497000-1366137074_thumb.jpg

 

post-37356-0-23161100-1366137227_thumb.jpg

 

And what do you know!

 

After drying:

Arch height 15,5 mm

M5=360 Hz

M2=185 Hz

and stiffer

 

This would allow me to tune M5 down to 345 Hz and M2 to 165 Hz, plus at the same time acheive the target weight 95 g. Unfortunatly after a couple of hours the arch went back to 14.5 mm and the corners bending up again. M5=347 and M2=197

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Not much time for working on this project at the moment. Started working on top this weekend - purfling done.

 

post-37356-0-29245600-1366821864_thumb.jpg

 

From the experience in post #99 and from some really valuable advice I have an idea how to get back on track with the back plate.

Edges curling up after tuning at 0% is a much worse problem than I first expected. It effects the frequency, arch height and stiffness!

=> Don't tune at 0% MC%

 

Did another experiment, bending down the the edges with twine and could repeat the raise of M5 and lower M2 without steam and clamps!

 

Violin #6 is going to be made without heating the wood and at ~6% MC%.

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