Component Downbearing Gauge Measurements

[Ron Nossaman]

Hi David,

First of all, how did you get bearing measured in thousandths of an inch
from a gauge calibrated in 3/16 degree increments? Without knowing how the
numbers were arrived at, it's hard to know what they mean. Second, did you
check the crown of the board? Crawl underneath with your flashlight and
state-of-the-art black thread for use as a straightedge and make sure there
is crown. Check at more than one spot, especially under that D4. These
numbers are too weird, maybe you can clarify a bit?

Ron   



 
At 03:24 PM 2/20/98 -0600, you wrote:
>Ladies and Gentlemen,
>
>Last night I eagerly opened the large box from Pianotek Supply Co., and
>reverently opened the little box containing my new Lowell Component
>Downbearing Gauge.
>
>Today, eager to learn to use my new tool, I took some measurements of
>downbearing on a customer's grand piano.  Here are the measurements.
>
>Note    Rear downbearing   Front downbearing   Tail length
>B0        -.027"               +.021"            3"
>B1        +.003"               +.021"            3 3/4"
>E2        +.024"               +.030"            4"
>A2        +.036                +.033"            4 1/2"
>D4          0.0                +.006"            4"
>C#5       +.010"               +.015"            3 3/4"
>E5        +.012"               +.009"            3 1/2"
>F#6       +.015"               +.006"            2"
>A6        +.015"               +.015"            2"
>F7        +.003"               +.003"            2"
>C8        +.005"               Couldn't measure  1" 
>
>I am confident of the numbers, because I double checked, but I can't
>guarantee that I put the + or - sign correctly in front of the numbers.
>
>The piano in question is a nondescript 5'6" 1928 Kurtzman grand locally
>rebuilt 2 years ago with soundboard shims, a new bass bridge, treble bridge
>repairs, a new pinblock and tuning pins and strings, and new hammers.  At
>the time I first saw it I was very impressed with the work.  But since
>then, tone problems have been plaguing this piano.  I am wondering if these
>tone problems can be solved by more regulation and voicing.  Or is it
>possible that no matter what I do, the tone will never improve because of
>downbearing problems?
>
>I don't know how to interpret the results of my measurements.  Some of the
>numbers seem to be off a bit.
>
>If you feel like answering, help is appreciated!
>
>Sincerely,
>
>
>David A. Vanderhoofven, RPT
>#pianotech page:  
>http://www.clandjop.com/~dkvander/ircpiano.html
>
>New web page for the Joplin Community Concert Association
>http://www.concerts.joplin.com
>
>
 Ron Nossaman