Pianotech

  • 1.  Grand Trichord Dampers - shaping and fitting

    Member
    Posted 13 days ago

    I'm replacing dampers on my old chickering grand and the project is going fine but I'm seeking information on tools and techniques for fitting the tricord dampers. 

    I purchased tricord felt strip from schaff and they are close to a perfect fit, but the problem is that they just don't seem like they will seat very well unless I trim and shape them. 

    Is it common to have to trim. shape and align the tricords and what is are the techniques involved in this? 

    If you can point me to any articles in the archives I would be appreciative of that too. 

    Thanks in advance for your advice and guidance!

    Sean 



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    Sean Stafford
    Endicott NY
    (607) 239-4643
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  • 2.  RE: Grand Trichord Dampers - shaping and fitting

    Registered Piano Technician
    Posted 13 days ago

    Are you gluing them on the blocks before you put them into the piano, or placing the felt on the strings and lowering the block onto the felt and allowing them to dry in place?  Is the grain orientation of the felt the same as the ones you took out?  Is one leg of the damper felt thicker than the other one?  Are the strings leveled?

    I assume you have duplicated the length of the felt pieces and thickness of the flats if they are mixed on a block.  Sometimes you might find it helpful to cut the "V" a little deeper to allow the two legs to move independently, even adding some thin cord in there to spread the two legs apart.

    Just some things to consider.



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    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
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    Original Message


  • 3.  RE: Grand Trichord Dampers - shaping and fitting

    Registered Piano Technician
    Posted 13 days ago

    Andrew Remillard's article, called "Dampers: Peace and Quiet at Last" in the December 2002 issue has some nice diagrams and general wisdom about selecting/replacing damper felt.  Including some pictures of what Paul suggested w/rt adding cord to spread the legs apart.

    You actually don't _want_ the trichord felt to stab down between the strings too far.  That's actually a condition that tends to develop over time as the felt gets compacted in places from being pushed against the wire.  It then starts to cause zingy sounds when the damper is lifted.  So if your concern about the fit comes from having the "legs" seeming bit too fat, you might want to just go ahead and install one as is and see how it does.  It's going to settle in a bit, especially if you got the Laoreaux stuff which is very soft.

    There is a keyword journal search function here where you can find more articles: https://my.ptg.org/ptgeducation/index .  Not meaning to tell you to "google it", it's just that we know it's not as well-publicized of a feature as it could be...



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    Nathan Monteleone RPT
    Fort Worth TX
    (817) 675-9494
    nbmont@gmail.com
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    Original Message


  • 4.  RE: Grand Trichord Dampers - shaping and fitting

    Registered Piano Technician
    Posted 12 days ago

    Yes it's common to address this. First run a razor blade down the center to open up the damper slightly. Insert a piece of kite string or equivalent in the center cut to slightly spread the damper. Trim the felt so that it doesn't protrude below the level of the string s (anything below the level of the string isn't doing anything and this will help eliminate "bowing effect" or damper "whoosh"). If you glue the felt on the head before you install you may have to do some adjustment side to side to get the damper centered over the strings if you don't, you won't but the damper felt might not be centered on the damper head. I prefer the former. 



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    David Love RPT
    www.davidlovepianos.com
    davidlovepianos@comcast.net
    415 407 8320
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    Original Message


  • 5.  RE: Grand Trichord Dampers - shaping and fitting

    Registered Piano Technician
    Posted 12 days ago

    Sean (Post #1), permit me a quick observation, not necessarily a remedy: be aware the string spacing within each tri-chord unison on a vintage Chickering is much narrower than on other pianos of the day. The agraffes were drilled with the three string holes noticeably closer together. This can make damper work on these pianos vexing at times.

    I would suggest using the narrowest tri-chord wedges you can find, and slit them well for optimal nestling into the unisons.



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    David Hughes RPT
    Vintage Case Parts
    Glyndon MD
    (443) 522-2201
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    Original Message


  • 6.  RE: Grand Trichord Dampers - shaping and fitting

    Registered Piano Technician
    Posted 10 days ago

    David,

    That is precisely what I did on my 121. 

    Peter Grey Piano Doctor 



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    Peter Grey
    Stratham NH
    (603) 686-2395
    pianodoctor57@gmail.com
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    Original Message