Pianotech

  • 1.  Accu-Just Hitch Pins in Baldwin Verticals

    Posted 06-10-2017 08:54
    Greetings All,

    Does anyone have any spec suggestions for Accu-Just hitch pin adjustments on a 48-inch Baldwin upright?

    I Installed a humidity control system in one this week and noticed that the strings were inconsistently aligned (even within sections of the piano and some of the strings were right at the open ends of the hitch pins).

    ------------------------------
    [Barbara] [Bernhardt]
    [Piano Technician/Co-Owner ]
    [GF Music, LLC]
    [Montrose] [CO]
    [(970)209-8817]
    ------------------------------


  • 2.  RE: Accu-Just Hitch Pins in Baldwin Verticals

    Registered Piano Technician
    Posted 06-10-2017 14:52
    Barb

    Baldwin grands have accujust hitch pins, and on those, the strings are on the pins so that the down bearing is even. I've never seen a Baldwin upright with accujust hitch pins, but I have feeling that someone at some point adjusted them. It will take a lot of work, but the only way to make them right would be to measure the down bearing on each string and adjust them accordingly. 

    On the other hand, if the piano sound fine, I would leave well enough alone.

    ------------------------------
    Willem "Wim" Blees, RPT
    Mililani, HI 96789
    ------------------------------

    Original Message


  • 3.  RE: Accu-Just Hitch Pins in Baldwin Verticals

    Registered Piano Technician
    Posted 06-14-2017 09:10
    Good morning Barbara,

    The Baldwin model 248 (the 48" model) and the model 6000 (52" model) both used Accu-just (adjustable string height on a roll pin) like the Baldwin grands. There were original factory spec that were used to set those but they are to be applied while stringing the piano and aren't intended for "resetting" the tail heights.

    Those pianos are designed for minimal downbearing as well as several other design points. From what I've learned, the intent was for the string to be set lower on the pin rather than up at the top but wound up that way due some other manufacturing variations.

    Unless the piano has been poorly restrung or exhibits tonal issues, as Wim said, it's probably best to leave it as is.

    I hope this helps.

    AG

    ------------------------------
    Allan Gilreath, RPT
    Registered Piano Technician & President
    Allan Gilreath & Associates, Inc
    Calhoun, GA
    706-602-7667
    allan@allangilreath.com - www.allangilreath.com
    ------------------------------

    Original Message


  • 4.  RE: Accu-Just Hitch Pins in Baldwin Verticals

    Registered Piano Technician
    Posted 06-14-2017 23:41
    There are two considerations here. First, string bearing should be accurately set. This is easily accomplished with vertical hitches -- but often is not. Roughly speaking the string deflection across the bridge should be approximately 1.0 degrees in the treble, 0.5 degrees through the tenor and from 0.2 - 0.5 degrees through the bass. This is best measured using a digital inclinometer such as the popular Wixey. 

    Second. the strings should not ride too high on the pins. My personal preference is for the strings to no higher than 5 - 6 mm off the surface of the string frame. This does, of course, require that the string frame be mounted correctly. They were not, always. 

    The strings should be level within each section. If some strings are abnormally higher or lower than the adjacent strings it is a clue that something is wrong. This should never -- as in, NEVER -- happen. In this case -- assuming the client is willing to pay you for your time -- it is a good idea to check a few strings and determine what you have to work with. 

    There is a tool for tapping the strings down -- you should not just take a screwdriver blade and pound away. The correct tool is easily made -- a piece of steel rod with a hole of appropriate diameter drilled into one end will do.  

    ​ddf​


    --
    Delwin D Fandrich
    Piano Design & Manufacturing Consultant
    6939 Foothill Court SW, Olympia, Washington 98512 USA
    Email  ddfandrich@gmail.com
    Tel  360 515 0119  --  Cell  360 388 6525



    Original Message