Pianotech

  • 1.  Damper Pedal Noise

    Posted 12-22-2023 16:27

    I would appreciate suggestions for the cause of a metallic click associated with the damper pedal of a Kawai 6-foot CA-40N that I service. I have isolated the problem to the external trapwork. If I put my hand on the brass push rod from the pedal I can feel the "click", and if I apply some horizontal pressure halfway up the  push rod while operating the pedal the noise/click goes away. It's true that the lyre posts have come unglued, but the noise is a metallic click – not a wood creak.

     

    I hope/figure that when I return in a couple days and remove the trapwork and disassemble the pedals in the lyre, I will see an issue with the metal damper pedal and its hinge rod. Agree? Can anyone suggest other possible causes that I should watch for? The two metal lyre braces seem to be well attached. The click occurs with/without the little rubber boot being at the bottom of the brass push rod.

     

    Thanks in advance. Regards, Norman



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    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
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  • 2.  RE: Damper Pedal Noise

    Registered Piano Technician
    Posted 12-22-2023 19:02
    Is there is a leather pad in the bottom of the hole of the pedal?  The click sounds like there is a ridge in the bottom of the hole, and the rod is moving over the ridge when the pedal is pushed. The rubber boot is only for the sides of the rod. 

    Just a thought.

    Wim





  • 3.  RE: Damper Pedal Noise

    Member
    Posted 12-22-2023 21:23

    My suggestion is to clean out the rubber boot the pedal rod sits in and to put two strips of buckskin in the hole Jam the pedal rod into them hole so ir makes a good impression. Cut the excess buckskin with sharp sciissors or an exacto This fix will take care of the rod hitting the sides of the cup or the bottom There also can be play/space in the pedal guide rail that the pedal rod passes through. If so rebush with a snug bushing cloth. Check the cups on the other pedals. I find that the rubber caps dry out, crack or are snug   

    **** Strip should be about 3/4 inch wide one vertical and one horizontal over the pedal cup hole - 3 to 4 " in length



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


  • 4.  RE: Damper Pedal Noise

    Posted 12-23-2023 08:30

    Wim and James, I think that you are right on.  Thanks much.  I'll keep you informed of how it goes.  Enjoy the Holidays.  Regards, Norman,.



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    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
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    Original Message


  • 5.  RE: Damper Pedal Noise

    Registered Piano Technician
    Posted 12-23-2023 09:46

    Another potential source of a click like this can be the interface between the pitman and the damper lift tray.  I was tracking down a noise on a Samick-built grand with an aluminum damper lift tray.  I figured out that there had originally been a rubber bushing inserted in the tray, but that it had crumbled away.  I keep a supply of rubber bushings from Yamaha (also Schaff 1083a) for the interfaces between the hammer rest rail/damper lift rod and the rods coming up from the pedals.  Cleaning the remaining gunk out of the hole in the damper lift tray made it possible for me to insert one of these and resolve the click.  It was too long--it extended above the tray surface--so I had to trim the top back.  A better choice of bushing would have been the Schaff 1083b or the Yamaha equivalent, but I was not carrying one at the time.



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    Floyd Gadd RPT
    Regina SK
    (306) 502-9103
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    Original Message


  • 6.  RE: Damper Pedal Noise

    Posted 12-23-2023 11:02

    If there are coil springs involved, check those. I have experienced some clicking with those in the past. A little lubricant on the ends of the spring corrected the problem.



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    Randy Prentice RPT
    Tucson AZ
    (520) 749-3788
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  • 7.  RE: Damper Pedal Noise

    Posted 12-24-2023 17:15

    Thank you to Wim and James.  I filed down a rough edge at the bottom of the brass push rod where it goes into the back of the pedal, put the rubber boot back on, and the metallic clicking noise was totally gone.  But this now left a creak!  Floyd was close on that -- where the base of the little dowel (going up to the aluminum damper tray) was seated in the round countersunk hole in the pitman was making the creak -- put some silicone on it.  Thank you to all who responded. Happy Holidays to all. Regards, Norman.



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    Norman Brickman
    Potomac Piano Service
    Potomac, Maryland
    potomacpiano@verizon.net
    https://potomacpiano.com
    (301) 983.9321
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    Original Message