Science

[E. Jensen]

I dont know if wood changes over time.  I really don't.  Not simply from time, all things being equal.  But I do know the wood growing now is different than wood from the past.  Yew is a great example.  There just is not a lot of 100 rpi around anymore.  Similar story across the board.  Stuff available to cut now is faster grown, which for a lot of woods means less dense, less stiff, more knots.  That could be part of the reason with the instruments.  I bet that ring count has a big impact on sound quality. 

[bradsmith2010]

I did not think of that, and that makes sense ,, infinitely fascinating ,,

[Dakota Kid]

I know that even the type of finish can have a huge impact on tone quality of wood. I don't suspect it comes into play much with bows, but I may be wrong. It may factor in if we're talking about sound dampening.

[PatM]

there have been many claims that older wood in instruments has a better sound,,Stratavarious for example,,the older wood producing the best sound,, that cannot be duplicated with any "newer" wood,, only the aged wood having the sound,, produced by curing and 100's of years of being exposed  to musical vibration,, I have read of some curing wood with music playing to duplicate the effect so desired,,
I am not sure I am convinced older wood is more likely to break,,and the old bows mentioned may have been stored in such a way to compromise the wood,, Ishi shot quite a few older bows to test them,,, and some more than 100 years old,, overdrew and shot well,,
I think the wood has changed since it was made 100 years ago,,in a positive or negative way I am not sure,, and I am sure it depends on the type of wood as well as to how older wood holds up as a bow,,,, no need to open that can of worms

      The Stradivarius sound doesn't hold up under scientific testing. The only time it sounds better is if the player knows it's a Stradivarius or is told that this is the instrument being played.

[bradsmith2010]

wow that is very interesting,,,

[loon]

Compression wood? Isn't it different on softwoods vs hardwoods? What about branch bows vs. sapling bows? Making branch bows would kill less trees;_; and branches are probably easier to get?

[E. Jensen]

Hardwoods only have tension wood, never compression wood.  Softwoods only have compression wood, never tensionwood.  Both are different from juvenile wood.  I'd imagine branch wood is also usually juvenile wood since it is in the crown.

[jeffp51]

More of this.  I love it.
The difference between scholarly research and red-neck know-how is the redneck learns from tradition and and personal experience, and the scholar tries to figure out the why behind it. The danger for the scholar comes when he ignores what experience has taught and thinks he knows better despite all evidence.  The danger for the redneck is the same, but the other way around.  Both can and should learn from the other, with a healthy dash of humility on both sides.

I once watched a group of engineering students at my school try to design a radio controlled airplane for a contest.  I have nearly 30 years of experience building and designing r/c aircraft, using mostly rule-of-thumb experience and that-looks-about-right engineering, and I have been pretty successful. The students were building with techniques and materials that I knew would result in complete failure--but in their minds, they were engineers, and the math told them it was going to work, no matter what I told them.  You can guess at the outcome.

[PatM]

More of this.  I love it.
The difference between scholarly research and red-neck know-how is the redneck learns from tradition and and personal experience, and the scholar tries to figure out the why behind it. The danger for the scholar comes when he ignores what experience has taught and thinks he knows better despite all evidence.  The danger for the redneck is the same, but the other way around.  Both can and should learn from the other, with a healthy dash of humility on both sides.

I once watched a group of engineering students at my school try to design a radio controlled airplane for a contest.  I have nearly 30 years of experience building and designing r/c aircraft, using mostly rule-of-thumb experience and that-looks-about-right engineering, and I have been pretty successful. The students were building with techniques and materials that I knew would result in complete failure--but in their minds, they were engineers, and the math told them it was going to work, no matter what I told them.  You can guess at the outcome.

This is why we still see engineering failures on a grand scale. All the math used is right except for the intuitive stuff that gets left  out entirely.  Engineers are also notoriously lousy builders.

[Jim Davis]

Actually, when there is an engineering failure, it is because there was a factor that wasn't recognized or somebody made a mistake with the math. The principles are rarely at fault, just the execution.

With the trial and error method, a best practice may result, but sometimes accompanied by no understanding of why it is best or how it might apply in other circumstances.

[PatM]

Actually, when there is an engineering failure, it is because there was a factor that wasn't recognized or somebody made a mistake with the math. The principles are rarely at fault, just the execution.

With the trial and error method, a best practice may result, but sometimes accompanied by no understanding of why it is best or how it might apply in other circumstances.

 The factor not recognized is the intuitive part.

[Badger]

  Something I would like to see done and would be fairly low tech and easy to establish would be a rating system designed specifically for bow woods.

     Example take a piece of wood that you might expect to come out mid range. Cut it 1/4"thick, 1' wide  and maybe 24" long. Cut into a pyramid shape. Clamp the wide end and then progressively bend it to correspond with a 1" incremental measure board that would accommodate the shape of the arc we are using. 1" back up, 2" back up. 3" return etc, measuring the weight each time, monitor at what point it first registered a weight loss due to set and continue until it has taken 1/4" set. The mark on the measure board would be the rating for elasticity.

    Each sample would be thickness ground not to match the test piece in thickness but to match it in weight at say the 6" mark. The thickness measure would express the stiffness. Some designs look more for stiffness and some more for elasticity. This would help to identify better woods for various designs.

[Jim Davis]

Tim Baker did related tests many years ago and the results are listed in (I think) Traditional Bowyer's Bible Vol I.

[jeffp51]

I am interested in what happens on a cellular level when a bow is heat treated, when it is drawn and when it is released, or what happens that causes set.  Things like that.  I think some things are mostly untestable, because each piece of wood is different, so you have difficulty repeating an experiment.  Other things would be testable.

[Springbuck]

Actually, when there is an engineering failure, it is because there was a factor that wasn't recognized or somebody made a mistake with the math. The principles are rarely at fault, just the execution.

With the trial and error method, a best practice may result, but sometimes accompanied by no understanding of why it is best or how it might apply in other circumstances.

Yep. Math doesn't lie, but bad or incomplete math will kill you.