In defense of TAR (Was S&S retrofit rails ?)

[John Hartman]

You wrote:
 
>  Traveling hammers waste power, they often bend on heavy blows, 

Well yes and no. A glancing blow delivers less power. Shanks bend on
heavy blows regardless of travel.

I think you are right about the loss of power but how much are we
talking about. I found the old trig table and did some simple vector
analysis. With a blow distance of 44mm and deflection from vertical of
3mm the hammer travels at angle of 3*54'. I chose 3mm because that is
the most I would typically de-travel the shank to hit a hammer. A vector
tilted at this angle has a vertical component of  .23% less. To do this
calculation assign the vector a value of 100. So cos. 3*54' times 100
equals 99.768. The remainder is .23. This is a power loss of less than a
¼ of one percent. I am not overly concerned about loosing tone  power as
a result of de-traveling hammers. This fits my experience of not hearing
a loss of tone in the areas I have used this technique. Just out of
curiosity I figured the deflection needed to reach 1%. With a blow
distance of 44mm the hammer would have to space over 6.25mm (1/4"). The
conclusion I would make is that as long as we don't over do it and
space  hammers with this technique beyond say 3 or 4mm the loss in power
is insignificant. 

 
>I would suggest that
> hammer and string spacing be thought of compromise here, attempting to keep
> the strings as straight as possible.  A poorly set up action could have
> someone moving all the strings out of place.

Yes, you are right, thank you Ed

John Hartman
Beacon NY
>From scratch Soundboards and Keyboards