Topic Thread

  • 1.  Piano Disc Piano action brackets

    Member
    Posted 05-21-2022 20:20

      I have been working on a Piano Disc piano on which I had to replace the expanding action brackets . it was impossible to get the top stack off they had expanded so tightly on the frame. Young Chang made the brackets for several lines of pianos and this piano was one of them. I installed a Prodigy piano disc wireless system and regulated the piano after setting the action spread at 112.5 but instructions I have from YC  state models newer than 1992 should be set to 113.5  because let off buttons are at a 90 degree angle to the hammer rail. I have not been able to exactly date the piano because the Pierce Atlas lists only Young Chang serial numbers.  There was a date on the PDS 128 of 1991 but that was when the PD unit was made. If I used the wrong action spread what should I look for that is not working right ?  It seemed fine but after weeks of using the player system and playing without the player the action is all over the place with backchecking, hammer line and after touch issues. Perhaps the action spread moved or there is a mis-alignment and different spreads at each bracket. Does anyone have experience doing the expanding action replacement on Piano Disc brand pianos ? Any regulation specs as a starting point. I have done several action replacement jobs on other pianos along with regulation and not had any issues . Maybe I have to do something different with this brand ?

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 2.  RE: Piano Disc Piano action brackets

    Member
    Posted 05-21-2022 21:21
    Proper action spread has the knuckle core aligned with the jack center at rest. In other words,
    when the hammer is at rest, the knuckle core should be pointing at the jack center

    Another aspect is rail heights. String height minus hammer bore (considering wear) equals Hammer Center Height (HCH).
    The Wippen Center Height is 64 mm below HCH.

    The last one of these that I worked on; I had to repin the top action get the friction correct on the hammers/jacks/rep lever;
    to get the repetition working properly when adjusted through the player unit.
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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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  • 3.  RE: Piano Disc Piano action brackets

    Registered Piano Technician
    Posted 05-22-2022 09:26
    James

    First, yes, Young Chang did make the Piano Disc. pianos. 
    I would set the action spread at 112.5 and see what happens. The other thing that might help, unless you or someone else adjusted them. is to line up the front edge of the jack with the back edge of the knuckle core. Move the wippen rail on the note #1 and #88, and then make sure the rest of the jacks are set the same way. You might have to adjust all of them a little. 

    Wim






  • 4.  RE: Piano Disc Piano action brackets

    Member
    Posted 05-22-2022 16:15
    The back edge of the jack lines up with the back edge of the knuckle core (front being towards the keyboard). Better repetition can be had by aligning the back edge of the jack with the center of the knuckle core but be careful, notes can 'cheat' in this configuration.

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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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  • 5.  RE: Piano Disc Piano action brackets

    Member
    Posted 05-25-2022 23:55
    This is an update on the situation . I thoroughly went through the piano regulation yesterday and the day before determine to get this piano playing properly both as a piano and a piano disc player. The action spread was off a tiny amount on each end. I used a new electronic caliper with sharp points and set it to 112.5 mm , tapped one end in and the other out and tightened screws down - remeasured and made sure action spread was the same on all brackets. I noticed the jack toes not well centered on the letoff buttons and the hammer rebound rail way too high. The hammer blow was far too great over 50mm . rep springs where fine overall . The biggest changes needed to be the hammer blow , some drop screws and letoff. Things fell into place and I got aftertouch back. Several passes through the action including adjusting letoff in the piano made a huge huge difference. The piano action played well and after using the piano disc calibration software it sounded great. One tricky piano disc thing is to get the pedal solenoid adjusted properly. This requires getting the manual damper lift with the pedal to lift the dampers just above the strings. The solenoid needs to be adjusted properly , tested and locked in. Since I just had re-certification training at the factory this was easy because we did it in class on a complete PD install. There is no substitute for hands on class instruction. Since there where no Piano Disc regulation guidelines I used the YC specs in the action handbook that Randy Potter published

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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