[pianotech] SSM evaluation

[Ron Nossaman]

Gene Nelson wrote:
> Hello list,
> Doing an evaluation of a 8 year old SSM I found that there is very high 
> front bearing in the high treble measured at f7 = nine divisions on the 
> Lowell Bubble Gauge or .027", two divisions at f6, negative 5 divisions 
> at f5, then two positive at f4 and mostly the same through the long and 
> bass bridges.

Degrees is easier on everyone. The Lowell gage is calibrated 
in 10' increments, or 1/6° per graduation. A 1.5° in the high 
treble isn't really out of line.


> This is total bearing - leveled the guage on speaking length and measure 
> tail.

Good enough. For this purpose, net bearing is all you need.


> I could measure crown under the board in the middle but it is flat in 
> the bass and almost flat in the treble with possibly 1/64" crown.
> The tone and sustain at c5 through e6 are reasonably good with power and 
> color.
> I am curious if the negative bearing at f5 would be a disqualifier so 
> that I should not recomend the piano to my client?
> Thanks for any insights.
> Gene

You have a vanishingly small crown where the bearing is -0.8°. 
The board is dead. You'll likely hear that clearly when the 
humidity drops next heating season and the customer complains.

Good rebuild candidate, but I wouldn't recommend it for a 
dependable instrument as is.
Ron N