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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