[CAUT] Touchweight, etc.

[Horace Greeley]

Everything Fred said, _and_ taking the measurements I recommended earlier.

All of this, calculating BW & etc, taking care of friction and making 
reasonably careful measurements of action parts and their relationships 
with the instrument in which they are installed are integral parts of the 
larger both/and practice of establishing a foundational understanding of 
where you are before you start simply swapping out parts.

Horace

At 12:28 PM 8/1/2005, you wrote:
>On 8/1/05 12:10 PM, "David Love" <davidlovepianos@comcast.net> wrote:
>
> > If you measure the up and down weight on the notes you are sampling you 
> will
> > be able to calculate the friction and know instantly whether you have a
> > friction problem or not.
> >
> > David Love
> > davidlovepianos@comcast.net
>
>Yes, and that would certainly be a first step in looking at an action for
>the first time and doing a preliminary analysis. But it is very
>time-consuming to go through the whole piano, writing all that down and
>calculating BW and so forth. If you do this prior to addressing frictional
>issues, it is a very inefficient approach, in my experience. For instance,
>if there are major frictional issues (could be vertigris-like, could be
>loose knuckle leather, felt knuckles, a number of other possibilities), the
>BW one calculates from the DW and UW will not be the same as the one
>obtained after addressing the frictional issues. Theoretically the friction
>should be calculable from DW and UW, and within limits it is. But I have
>found on more than one occasion that a piano I diagnosed as having too high
>a BW from initial readings turned out to be not so bad after addressing
>friction. IOW, the calculated friction was not the same as the actual
>friction, and reducing it took more from the "high side" than the low (of
>the difference between DW and UW). That's my experience, and is one thing
>that has led me to a different approach: get the action within parameters
>first, before drawing any conclusions. Charting DW, UW, BW, etc comes after
>the action (or samples in the action) has had issues addressed.
>Regards,
>Fred Sturm
>University of New Mexico
>
>
>
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