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Tuesday, 28 October 2014

Regulating an Upright Piano

Regulating a upright piano is perhaps just a little more straightforward than regulating a grand piano. The following method for regulating is not the only way, but it works well on most pianos.


Please note: while regulating pianos, some improvisation is required to get the best out of any given piano. If various felts have been replaced, there are many more issues to deal with than can be addressed in this article. The finer points of the slap-rails are not mentioned here either.

Most actions work well if the depth of touch is 10.5 mm. and the hammer blow 47mm. 

Assuming the action has been reassembled and everything is spaced properly.




1. The first job, somewhat surprisingly, is to adjust the set-off point! With the action in the piano this can be done without the keys - indeed, it is better they are not in the piano! Lifting the front of the lower part of the action the set-off is easy to find and adjust. If access to the set-off screws is awkward you can even take off the hammer-rest bar. Set-off distance is 2 - 3 mm from the strings.

It is also helpful if the back-checks are bent away from the balance hammer to allow the set-off plenty of room to let hammer to fall away at the set-off point.

2. Replace the hammer-rest bar and set the blow to 47 mm (no more than 50 mm). With the keys back in the piano, and the hammer blow set, take out the lost motion between the key and the lever. (The lower part of the action).


Starting with the white keys, establish that when depressed and held down, the tops of the key-covers are level. With this done, set the depth of touch. Using sample white keys - every 5 or so, (e.g. a 'C' a 'G' a 'D') measure from the top surface of a 'held down' note to the top surface of a neighbouring key when at rest (ready to be played). This should be 10.5 mm. After setting the sample keys, level the remaining keys to be in line with them.

Now for the sharps: When depressed and held down, the top surface of the sharp keys should show about 1.5 mm above the top surface of the white keys when at rest. Adjust accordingly. once again, using sample keys - every 4 or 5, set the height of the top surface of the sharp keys when at rest, to be 12 mm above the top surface of the white keys when at rest.


3. Set the checking-off  - the point at which the hammer is caught by the back-check when the key is struck and held down. Usually measured as the distance between the strings and where the hammer has come to rest. There can be no fixed measurement here as it seems to be different for every piano. I would reckon on anything from 8 mm to 15 mm. This is a subjective point but when it is right you can feel the whole key-stroke reach its proper destination!


4. Regulate the dampers so that they all lift together on the pedal AND during the stroke of the key, the damper begins to lift away from the string when the hammer is about halfway to the strike-point.  

Technical File

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Pianology

Nathaniel Berry Serial Nos.


Year
Serial No.
Year
Serial No.
1896
6880
1930
26699
1898
7450
1932
29229
1900
8250
1934
31547
1902
8908
1936
34652
1904
9500
1938
38522
1906
10503
1940
41700
1908
11246
1942
42250
1910
12159
1946
42290
1912
12676
1947
42320
1914
13347
1948
42450
1916
14265
1950
42700
1918
16000
1952
43050
1920
17000
1954
43383
1922
18272
1956
44260
1924
19945
1958
44614
1926
21713
1960
45084
1928
24159
1966
46191
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Baldwin Serial Nos.


Year
Serial No.
Year
Serial No.
1925
48000
1970
190028
1930
63000
1972
195485
1935
74600
1974
204113
1940
88700
1976
213470
1941
91000
1978
222683
1943
102000
1980
236654
1948
105000
1982
248306
1950
110243
1984
257293
1952
118244
1986
266329
1954
125050
1988
278556
1956
131515
1990
290656
1958
138559
1992
307561
1960
145002
1994
322347
1962
152706
1996
335514
1964
160868
1998
349726
1966
170652
2000
366583
1968
179702
2002
380584
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Allison Serial Nos.


Year
Serial No.
Year
Serial No.
1890
21000
1924
48400
1892
22600
1926
49800
1894
24200
1928
50800
1896
24700
1930
52000
1898
25800
1932
53000
1900
29000
1934
53800
1902
30000
1936
54800
1904
32000
1938
55800
1906
34000
1940
56800
1908
36000
1942
57000
1910
38000
1947
57100
1912
40600
1949
57520
1914
41600
1951
59000
1916
42800
1953
57900
1918
44400
1955
58095
1920
46000
1957
58300
1922
47200
1959
58700
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