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Any suggestions? That is for the purfling not the attitude.

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I'm certain, based on what I've seen so far, that you have the skill to take a very narrow chisel and make a V-shaped hole, then wedge in a small piece of purfling to make it disappear completely.  If you felt like it. Or use a center-clamp chinrest, which would also make it disappear.

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Nice to be in the workshop if only for a couple of hours.

 

The plate wants to be thin in the middle, M2 won't go down (185 Hz). I Think the arch should have had to be 0,5 - 1 mm higher and have a  "longer" curve.

I'm going to leave the back for now and start with the top.

 

107 g, M5=355 Hz, MC ~6%

 

Soundpost area 4,7 mm

C-bout edges 4 mm

Middle 4 - 4,3 mm

 

post-37356-0-00051600-1387041386_thumb.jpgpost-37356-0-83575200-1387041397_thumb.jpg

post-37356-0-49844900-1387041407_thumb.jpgpost-37356-0-43693000-1387041420_thumb.jpg

 

 

 

 

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Couldn't leave the back yet so I continued fine tuning today. The measures are almost identical to #5.

There is no such thing as a stable M5 at this stage and extreme starting volume. I can vary M5 between 335 - 350 Hz by moisturing the inside or outside with a wet cloth and drying with a hair drier. Arch height can differ 1-2 mm, edges curling up or straightened out by moistureing the outside)

 

When arch height is set to starting point 13,7 mm and edges are flat (no curling up), MC ~6-7%, M5 is 340 Hz, and M2=169. My arching style could need 15-20 extra Hz when tuning extrados.

 

post-37356-0-44174800-1387114365_thumb.jpg

 

B1+ will probably need final adjustments after violin is finished in the white. The plate will end up  ~97-98 g

 

http://www.maestronet.com/forum/index.php?/topic/327921-violin-5-strad-body-modes/page-8#entry585713

http://www.maestronet.com/forum/index.php?/topic/327921-violin-5-strad-body-modes/page-8#entry585728

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It's going to be a challenge to bring this top below 70 g. arch height is now 16,8 mm, It might be too low for this wood.

So the indications where right, when analyzing the wood properties

 

http://www.maestronet.com/forum/index.php?/topic/328430-peter-kgs-bench/page-5#entry599120
http://www.maestronet.com/forum/index.php?/topic/328430-peter-kgs-bench/page-9#entry606207

 

Need to be careful!

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Sorry, it will be a ~70 g plate. I tried my best :huh:  F-holes lies nicely on the sides more or less paralel to the edge. like most Cremonese instruments

 

Arch height 16,8 mm, with a curve like a back plate (It will look like that when the speed of sound is low)

Purfling channel in upper/lower extremities is ~3 mm and ~3,6 mm in c-bouts

 

post-37356-0-50768300-1387395467_thumb.jpgpost-37356-0-59420500-1387395479_thumb.jpg

post-37356-0-55057800-1387395490_thumb.jpgpost-37356-0-58731100-1387395500_thumb.jpg

 

No sandpaper ;)

 

 

 

 

 

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Hi Peter,

post-53756-0-42415500-1387399455_thumb.jpg

I have some definite problems with an arch shape like this. I think you are asking to much of this wood in relation to tuning. Yes, arch tuning can be/is important but perhaps more important is, for a lack of a better word, arch mobility. The shape of arch you have, being very flat at the highlighted areas, is too stiff to bend much and move the air within the box-which is what we want especially at low frequencies. I would try to stick with a more typical arching and respond to the tuning you get from it.

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Hi Peter,

attachicon.gifimage.jpg

I have some definite problems with an arch shape like this. I think you are asking to much of this wood in relation to tuning. Yes, arch tuning can be/is important but perhaps more important is, for a lack of a better word, arch mobility. The shape of arch you have, being very flat at the highlighted areas, is too stiff to bend much and move the air within the box-which is what we want especially at low frequencies. I would try to stick with a more typical arching and respond to the tuning you get from it.

 

Thanks, I think you have a very good point!

 

One option would be to make another top. On the other hand I want to see how it turns out. I have some really high performance wood that I'm saving for when I'm ready for it. For the next I'm going to choose higher dens maple with lower speed of sound and higher dens Finnish spruce.

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Thanks, I think you have a very good point!

 

One option would be to make another top. On the other hand I want to see how it turns out. I have some really high performance wood that I'm saving for when I'm ready for it. For the next I'm going to choose higher dens maple with lower speed of sound and higher dens Finnish spruce.

What is the Finnish spruce like. Higher density you say. How high generally? Speed of sound?

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What is the Finnish spruce like. Higher density you say. How high generally? Speed of sound?

 

In general denser and stronger. Dark growth rings are generally wider in relation to spring Wood, but It depends a lot on where it is grown.

Speed of sound I don't know but I measured some Finnish spruce with Don's method and they vary in the same range as bought tonewood.

 

We have a lot of it, It's called Finnish green gold.

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I think I know how to tune plates :rolleyes:

Didn't think I would be able to do this with that kind of wood - low speed of sound and low density (0,37 g/cm3)

 

Graduation 2,5 - 3,5 mm

arch height 16,3 mm

MC% = 4,5

M2=158

M5=345

w = 65 g

 

Great techinque to leave a little margin and tune both from the in- and outside, then it's possible to get it exactly

 

post-37356-0-97299400-1387568109_thumb.jpg

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I think I know how to tune plates :rolleyes:

Didn't think I would be able to do this with that kind of wood - low speed of sound and low density (0,37 g/cm3)

 

Graduation 2,5 - 3,5 mm

arch height 16,3 mm

MC% = 4,5

M2=158

M5=345

w = 65 g

 

 

 

What happens to these 'tuned' numbers at a MC % more typical of a concert hall?

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What happens to these 'tuned' numbers at a MC % more typical of a concert hall?

 

Janito,

 

I don't know if your question was serious or a jeering remark? But I'll answer it anyway.

Every violin in nordic countries have 4,5 % and lower MC% from Jan - May.

 

I didn't do anything to get to 4,5% just measure it, to know how to tune (same plate can vary  335 - 355 Hz, between 1-12% MC) In a humid concert hall this particular violin will have a B1- around 430 Hz and B1+ around 525 Hz.

 

Peter

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 In a humid concert hall this particular violin will have a B1- around 430 Hz and B1+ around 525 Hz.

 

 

I am continually mystified by the extraordinary attention to the mode frequencies and the effort expended to attain a particular goal... when there's ample evidence that it isn't of paramount importance to anyone else.  If your goal is hitting numbers, fine; that's a harmless hobby.  But here's what the universe (well, part of it) looks like, with data taken from Curtin's article and my own instruments:

post-25192-0-64526100-1387632965_thumb.jpg

 

My stuff tends to be on the lower half of the Strad stuff, which is really not too surprising, as I tend to follow Strad-ish dimensions, and experiment a lot trying to go lighter... and I also have a personal preference for that tonal character.

 

Your target looks to be a little on the low side, particularly the B1+.  But so what?  If there's any evidence that one particular spot on the plot is better than any other, nobody has shown it yet.

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Janito,

 

I don't know if your question was serious or a jeering remark? But I'll answer it anyway.

Every violin in nordic countries have 4,5 % and lower MC% from Jan - May.

 

I didn't do anything to get to 4,5% just measure it, to know how to tune (same plate can vary  335 - 355 Hz, between 1-12% MC) In a humid concert hall this particular violin will have a B1- around 430 Hz and B1+ around 525 Hz.

 

Peter

 

I never jeer, but I can be a non-believer.

 

I asked because I recently went to a house that had a small concert hall where the owner and a troop of PhDs converted old wax recordings into 'new' ones via superb pianos etc.  I was given a lecture on the importance of humidity, temp etc control to ensure that recordings could be made at different times and still be able to be stitched together seamlessly.

 

Bon voyage.

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F-holes, this is the easy part, now I need a good knife, which I don't have...

 

attachicon.giff-holes_21122013_6.jpg

Hi Peter,

You need to be careful cutting so close to the outside of the hole with a saw,

too much wood is lost so it cannot be cleaned up so easily, and you could end up with too thin

on the edge of the hole, like a razor, then it is easily damaged with the post setter.

Good work, Be careful !

We are ALWAYS learning !

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