[CAUT] [pianotech] Baldwin Accujust

Bob Hull hullfam5 at yahoo.com
Thu Jun 11 15:37:38 MDT 2009


Are these directions saying to bring all treble strings up to 440 and adjust string ht. and measure with the lowell gauge before putting the bass strings on?  You obviously can't measure with the gauge on the tenor area with the bass strings in the way.

Bob Hull


----- Original Message ----
From: Alan McCoy <amccoy at mail.ewu.edu>
To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org>
Sent: Monday, April 27, 2009 11:52:15 AM
Subject: Re: [CAUT] [pianotech] Baldwin Accujust

Ron,

Thanks for supplying this information. Much appreciated.

Alan McCoy


> From: Ron Nossaman <rnossaman at cox.net>
> Reply-To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org>
> Date: Thu, 23 Apr 2009 16:10:05 -0500
> To: Pianotech <pianotech at ptg.org>, "College and University Technicians
> <caut at ptg.org>" <caut at ptg.org>
> Subject: Re: [CAUT] [pianotech] Baldwin Accujust
> 
> Scott Rogers wrote:
>> I have a Baldwin L to restring, and I can't remember what steps are
>> necessary to setting proper down bearing with the accu-just hitch pins.
>> I know Baldwin used to loan out a downbearing gauge for setting DB on
>> each unison. Does anyone know if they still offer this, and if so
>> contact #'s?
>> Thanks for your help.
>> Scott Rogers, RPT
> 
> Bearing1.txt is from a Baldwin tech sheet, direct from the source.
> Bearing4.txt is a conversion chart to relate the instructions
> in bearing1 to degrees, so you can use a Lowell gage, Wixey,
> or whatever, instead of Baldwin's gage.
> 
> Ron N
> 
>    Bubble reading to Degrees to Bearing Load conversion
>    for Lowell and Baldwin downbearing gauges.
> 
>    Measure bubble offset difference between string segments
>    on both sides of the bridge. Look up angle and bearing factor
>    on appropriate chart. For bearing load in pounds, multiply
>    bearing factor times string tension.
> 
>    Ron Nossaman July, 1997
> 
>         Baldwin Gauge            |        Lowell Gauge
>    ------------------------------|-----------------------------
>      Bubble Degrees   Bearing    |     Bubble Degrees   Bearing
>    ------------------------------|-----------------------------
>      0.5    0.14167   0.0025     |     0.5    0.08333   0.0015
>      1.0    0.28333   0.005      |     1.0    0.16667   0.003
>      1.5    0.42499   0.0075     |     1.5    0.25      0.0045
>      2.0    0.56666   0.01       |     2.0    0.33333   0.006
>      2.5    0.70832   0.0125     |     2.5    0.41667   0.0075
>      3.0    0.84999   0.015      |     3.0    0.5       0.009
>      3.5    0.99165   0.0175     |     3.5    0.58333   0.0105
>      4.0    1.13332   0.02       |     4.0    0.66667   0.012
>      4.5    1.27499   0.0225     |     4.5    0.75      0.0135
>      5.0    1.41665   0.025      |     5.0    0.83333   0.015
>      5.5    1.55832   0.0275     |     5.5    0.91667   0.0165
>      6.0    1.69998   0.03       |     6.0    1.        0.018
>      6.5    1.84165   0.0325     |     6.5    1.08333   0.0195
>      7.0    1.98331   0.035      |     7.0    1.16667   0.021
>      7.5    2.12497   0.0375     |     7.5    1.25      0.0225
>      8.0    2.26664   0.04       |     8.0    1.33333   0.024
>      8.5    2.40831   0.0425     |     8.5    1.41667   0.0255
>      9.0    2.54997   0.045      |     9.0    1.5       0.027
>      9.5    2.69163   0.0475     |     9.5    1.58333   0.0285
>      10.0   2.8333    0.05       |     10.0   1.66667   0.03
>      10.5   2.97497   0.0525     |     10.5   1.75      0.0315
>      11.0   3.11663   0.055      |     11.0   1.83333   0.033
>      11.5   3.25829   0.0575     |     11.5   1.91667   0.0345
>      12.0   3.39996   0.06       |     12.0   2.        0.036
>      12.5   3.54163   0.0625     |     12.5   2.08333   0.0375
>      13.0   3.68329   0.065      |     13.0   2.16667   0.039
>      13.5   3.82496   0.0675     |     13.5   2.25      0.0405
>      14.0   3.96662   0.07       |     14.0   2.33333   0.042
>      14.5   4.10829   0.0725     |     14.5   2.41667   0.0435
>      15.0   4.24995   0.075      |     15.0   2.5       0.045
>      15.5   4.39162   0.0775     |     15.5   2.58333   0.0465
>      16.0   4.53328   0.08       |     16.0   2.66667   0.048
> 1-29-1997        
> TS039D 
> 
> PROCEDURE TO ESTABLISH PROPER DOWN BEARING OF STRINGS ON BRIDGES OF BALDWIN
> GRAND  PIANOS DESLGNED WITH HOLLOW VERTICAL (ACU-JUST) HITCH PINS
> 
> These conditions must exist before bearing can be established:
> 
> 1.All strings associated with the treble bridge must be in place,  (Bass
> strings to be installed later.)
> 
> 2.  These strings must be tuned to A-440 pitch.
> 
> 3.  All strings on the treble bridge must be set at proper height on their
> hitch pins to read zero (0.0) bearing at the bridge.  Follow this procedure;
> begin at treble end of treble bridge with note #88 and work toward bass.  Lift
> wire and raise tension of the strings on the first ten (10) notes,  Then raise
> wire and adjust tension of the next ten (10) notes and proceed on until all
> wire is adjusted in this manner on the treble bridge.
> 
> Procedure for string height adjustment.
> 
> 1.  Become familiar with bubble gage adjustments and application as shown with
> the attached illustrations,
> 2.  With strings at normal tension, begin with strings at the bass end of the
> treble bridge and work toward the middle,  Set bearing values as shown in the
> following chart on specified notes only.  Tap the string down by placing the
> tool over the hitch pin, resting on the wire,  with the bubble gage held onto
> proper strings with the magnet built into its base, tap the setting tool with
> a small hammer to lower the string to achieve a proper bubble gage reading.
> If the string is too low, raise the string, using a coil lifter and leather or
> felt to protect the plate finish.
> 
> Scale                      SA(5'2")    ST(5'8")    SC(6'3'')    SF10(7'0")
> SD10(9'0'') 
> Notes to be set            27-44       27-43       23-40        21-39
> 21-35 
> Bubble Deflection          1 divis.    1 divis.    1 divis.     1 divis.
> 1 divis.  
> 
> 3.  After strings associated with the notes which were adjusted in the
> preceding operation have been set, proceed on with notes listed in the
> following charts.
> 
> Scale                      SA(5' 2")   ST(5'8")    SC(6'3'')    SF10(7'0")
> SD10(9'0") 
> Notes to be set            45-53       44-53       41-53        40-53
> 36-53
> Bubble Deflection          2 divis.    2 divis.    2 divis.     2 divis.
> 2 divis.
> 
> Scale                      SA(5'2")    ST(5'8")    SC(6'3")     SF10(7'0")
> SD10(9'0") 
> Notes to be set            54-88       54-88       54-88        54-88
> 54-88
> Bubble Deflection          3 divis.    3 divis.    3 divis.     3 divis.
> 3 divis.
> 
> 4,  Install bass strings and set at zero bearing,  Then adjust bearing
> according to the following chart.
> 
> Scale                      SA(5'2")    ST(5'8")    SC(6'3")     SF10(7'0")
> SD10(9'0") 
> Notes to be set            1-26        1-26        1-20         1-20
> 1-20
> Bubble Deflection          1 divis.    1 divis.    1 divis.     1 divis.
> 1 divis 
> 
> 5.   Retune piano to A-440 pitch.
> 
> CONCLUSION:
> 
> 1. Bearing adjustments should only be made when the piano is maintained under
> proper climatic conditions.  (Humidity 35% - 45% with temperature 70 - 75)
> 
> 2. The procedure and bearing gage must be applied in the order established.
> 
> 3. A bearing value, previously set, cannot be rechecked because the
> accumulated force of all strings on the bridges will lower the soundboard and
> reduce the settings which were originally set.
> 
> 4. Pianos equipped with the vertical (Acu-Just) hitch pins are designed to
> function with a minimum positive bearing at the bridges, compared with other
> pianos with string rests and angled hitch pins.
> 
> *Hand written note at bottom: 1 div. = .005" shim thickness with a Baldwin
> Rocker Gage.


      


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