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Young Chang G185 Sostenuto

  • 1.  Young Chang G185 Sostenuto

    Posted 02-28-2018 19:21
    Trying to get the sostenuto bar/rod to turn freely and to catch the tabs on the dampers when pedal is pressed while playing notes . If you really stomp on both the sustain pedal and the middle sos pedal the rod rotates and catches all of the dampers and a slow release of the pedal allows dampers to randomly drop which is generally a good test . There is a spring steel  used inside the cavity to help reset the pedal dowel that comes through the keybed. This pitman  sits on the trap work lever under the piano. Everything appears to be connected properly so I am thinking the binding may be due to a tight dowel fit. Another thought is to re-position the rotating rods so the fin is at a 45 degree angle at rest. It is mostly straight up and down. I have some diagrams from the S&S technical manual but maybe there is something unique to a Young Chang. I replaced the action brackets at the end of last year and checked the action spread following the specs that came with the bracket The piano plays well and I have done some basic action regulation improving power  . Owner's son is an advanced student and taking lessons from an excellent teacher who may be starting him on pedalling exercises and shading so it is important to get the pedal system regulated. I may just end up taking off the trap lever and concentrate on the mechanical connections for now . The problem is that mom constantly wants to know the cost saying she does not want to put a lot into the piano. I am not sure how to take that since the young man has great ability, she got the piano at a fair price and dad is a successful home builder...

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    James Kelly
    Pawleys Island SC
    843-325-4357
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  • 2.  RE: Young Chang G185 Sostenuto

    Posted 03-01-2018 01:06
    Hi James:
    I'd first make sure that the pitman is assembled correctly. I think there's a wire loop that is attached to the sostenuto rod, and that loop is captured by the monkey. Take a good look at that arrangement and see if it makes sense. The wire should be in the proper place in the pitman for it to rotate.
    The pedal rod adjustment should be such that it allows the sostenuto mechanism to work properly. It the pedal rod is not set correctly, or the lyre is loose (check the joints), the sostenuto won't adjust or work properly. The sostenuto blade shouldn't be straight up and down, but at an angle, like you suggested. Otherwise it has to travel too far to do its job effectively. The blade edge should not interfere with the normal up and down of the underlevers, but with minimal movement should pick up the individual damper block tabs. The tabs should be just above the blade edge at rest.
    Without pics, it's hard to really know what's wrong, but the above could give you some hints.
    Good luck.
    Paul McCloud
    San DIego
    ___________________________________________________________________________________

    James Kelly
    Trying to get the sostenuto bar/rod to turn freely and to catch the tabs on the dampers when pedal is pressed while playing notes . If you really stomp on both the sustain pedal and the middle sos pedal the rod rotates and catches all of the dampers and a slow release of the pedal allows dampers to randomly drop which is generally a good test . There is a spring steel used inside the cavity to help reset the pedal dowel that comes through the keybed. This pitman sits on the trap work lever under the piano. Everything appears to be connected properly so I am thinking the binding may be due to a tight dowel fit. Another thought is to re-position the rotating rods so the fin is at a 45 degree angle at rest. It is mostly straight up and down. I have some diagrams from the S&S technical manual but maybe there is something unique to a Young Chang. I replaced the action brackets at the end of last year and checked the action spread following the specs that came with the bracket The piano plays well and I have done some basic action regulation improving power . Owner's son is an advanced student and taking lessons from an excellent teacher who may be starting him on pedalling exercises and shading so it is important to get the pedal system regulated. I may just end up taking off the trap lever and concentrate on the mechanical connections for now . The problem is that mom constantly wants to know the cost saying she does not want to put a lot into the piano. I am not sure how to take that since the young man has great ability, she got the piano at a fair price and dad is a successful home builder...

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    James Kelly
    Pawleys Island SC
    843-325-4357





  • 3.  RE: Young Chang G185 Sostenuto

    Posted 03-01-2018 07:51
    If you stomp on both bedals at the same time of course all the dampers get caught, Timing! Sos pedal befoe sust.

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    Larry Messerly, RPT
    Bringing Harmony to Homes
    www.lacrossepianotuning.com
    ljmesserly@gmail.com
    928-899-7292
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  • 4.  RE: Young Chang G185 Sostenuto

    Posted 03-01-2018 08:47
    Edited by Ed Sutton 03-01-2018 11:02
    If the sostenuto works when you press the right pedal first, then the first suspect is that damper lift on the key is not high enough. Lift one damper by hand and try the sostenuto pedal. If it works, then examine damper lift from the key. Is it shallow? [worn key felt]
    Or, less likely, is the damper upstop rail too high, and the damper pedal lifting too high, and the sostenuto rail also too high, therefore not catching the tabs on a normal damper lift from the key?
    Or something else.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 5.  RE: Young Chang G185 Sostenuto

    Posted 03-01-2018 09:13
    The rod at rest should be slightly above the tabs, 1.5 mm to 3 mm. Damper timing is irrelevant as all underlevers are lifted to the same height, lift would be dependent on key dip. The tabs should be 1.5 mm on the blade when engaged. If the sos does not hold all dampers after damper pedal lift, look at the tab alignment horizontally and vertically. Some wires may have to be bent to have the top flange inline. Shimming the tab rest felt may ib needed to align the tab height. A stop block on the trapwork helps with not over traveling.

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    Regards,

    Jon Page
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  • 6.  RE: Young Chang G185 Sostenuto

    Posted 03-01-2018 09:19
    Hi James.  The Pittman return spring may have been dislocated causing the fat wood dowel to bind in the hole through the keybed.  It's easily done.  You should be able to troubleshoot this with the action removed.  Check the linkage with the lifter rid to be sure the felt liner isn't binding on the metal lifter rod loop.

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