A response to just criticism

[Ron Overs]

David Love wrote:

  >Sorry Del, it was Ron Overs actually.  I'm still not sure what
   >hysteresis is exactly and why a leaf spring might have a problem
   >compared to a coil spring?  Ron, if you're listening?
   >
   >David Love
   >
Del responded:
   >
   >Hysteresis would only be a problem if leaf springs of multiple
   >layers were used. Then the breakaway friction between the various
   >leaves might cause a response problem. (Bearing in mind that I've
   >not actually tried this.) Otherwise, with a single leaf, I don't see
   >the problem. And I can't think of any reason to use a multiple leaf
   >spring arrangement for this application. Using a single leaf spring
   >it should be relatively easy to figure out a virtually frictionless
   >coupling between a leaf spring and the soundboard. Assuming, of
   >course, that one really wanted to use a leaf spring.
   >

I remember when this was under discussion earlier, Del mentioned 
using a connecting lever to connect a leaf spring to the panel. In 
this instance with a single leaf hysteresis loss would not be a 
problem. The hysteresis effect in multi leaf springs is essentially 
one of energy loss, or 'shock absorption'. When the adjacent leaves 
rub past each other, as they will when the load changes, energy will 
be lost in the form of heat.

This is why the earlier motor car designs with leaf springs were not 
so reliant upon the shock absorbers for energy absorption, whereas 
the modern motor car with coil springs will skip all over the road 
when the shock absorbers fail.

Best,

Ron O.
-- 
                  OVERS PIANOS
        Grand Piano Manufacturers
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Web:    http://www.overspianos.com.au
Email:  mailto:ron@overspianos.com.au
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