Marty Kasprzyk

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About Marty Kasprzyk

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  • Birthday 06/02/1945

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  • Location
    Olcott, NY, USA
  • Interests
    Wine making, gardening, dog training,
  1. Does a violin improve with age?

    The wine I make lasts a long time -- because nobody wants to drink it.
  2. Bridge Rocking Motion and Leverage

    I should have added that the wood's longitudinal speed Cl is equal to the wood elastic modulus E divided by its density p: Cl = E/p
  3. Bridge Rocking Motion and Leverage

    The speed of a bending wave Cb for a flat plate is equal to the square root of the product of a constant 6.28, the frequency f, longitudinal speed of sound Cl and the thickness t: Cb = (6.28fClt)^.5 for example with a 440Hz frequency f, a spruce wood having a longitudinal speed of sound Cl of 5600m/s and a thickness of 3mm (0.003m): Cb = (6.28*440*5600*0.003)^.5 =215meters/second The wave length L of the bending wave equals the bending wave's speed Cb divided by the frequency f. L = Cb/f So for our earlier example: L = 215/440 = 0.49 meter or 490mm The speed of a bending wave in an arched plate is faster than a flat plate because it is stiffer than a flat plate and there is more factors used in the above Cb equation which takes into account the arch's shape and height. But in general thick plates and a high speed of sound produces a high bending wave speed.
  4. Bridge Rocking Motion and Leverage

    You are mixing two different issues--strength and stiffness. If we are talking about sound character then we should be using stiffness or its inverse flexibility. If we are concerned with top cracking then use strength. Your sentences could read: "...but base it on the concept that tall arches are stiffer and thinner tops are needed to keep them flexible. Lower arches are not as stiff and thicker tops are needed to keep them adequately stiff." or "...but base it on the concept that tall arches are stronger so thinner tops can be used. Lower arches are not as strong so thicker tops are needed for strength." The bridge foot width affects the sound character and playability of violins. Attached is a pdf of one study. Jansson_Violin_frequency_response_bridge_mobility.pdf
  5. Perry Sultana...

    How are you choosing your thicknesses? Is it a copy of an earlier instrument?
  6. Neck Overstand

    You could use wider feet with a tall bridge and keep the height/width leverage the same.
  7. Messiah wood (again....)

    A flashlight or lantern might have helped.
  8. Minimum top thickness at sound post

    Rather than string tension I think it is the stretchiness of the strings that is important. Steel core strings stretch very little whereas gut or nylon core strings stretch a lot. Steel core strings have a rather fixed length and can't accommodate wood's dimensional changes from humidity changes without applying a lot of load on the instrument's body. It is my speculation that modern strings have made the various wood cracking problems worse.
  9. Importance of grain direction on maple backs

    Cut it up into ribs.
  10. Messiah wood (again....)

    Luca Primon had told me that he did exactly that for getting his spruce wood. He also said that he chose not to go to Bosnia for his maple because he was worried about the land mines in the forests left from the Bosnia war.
  11. Input needed colophony + nitrocellulose?

    If it is explosive maybe its best not to use it for a violin finish. But ok for violas.
  12. Input needed colophony + nitrocellulose?

    The varnish might be the same stuff as the glue used for joining the wood veneers.
  13. Berlioz, Paganini and the biggest viola you’ll ever see!!

    Repetitive stress injuries can be a serious problem. I cringe every time I see a player lift their left shoulder to help support their violin or viola (especially big violas). I see this poor technique so often that I’m starting to lose feeling in the left side of my face due to excessive cringing.
  14. Berlioz, Paganini and the biggest viola you’ll ever see!!

    Hi Ben, I'm hoping there is tiny market nobody else cares about for light violas for players who use large violas and have hand, wrist, arm, shoulder, jaw, neck, or back injuries. My last fairly big sounding viola weighed 428g with its chin rest and built in shoulder rest and pads. But it feels quite light because its center of gravity is close to the player.
  15. Elements of construction and responsiveness

    On second thought, if I needed Rolls or Bentley I would probably also want bullet proof windows and doors.