[pianotech] Noisey pedal bracket

[John Ashcraft]

I reworked a Yamaha-built Everett studio that was a wonderful piano in every
other respect.

The trapwork was designed to fail. The fulcrum should be on a line (or in
the vertical plane containing the line) connecting the force at the pedal
end with the load at the dowel end: another magic line, perhaps. When they
put that strong spring off the line, they forced the bracket to try to
absorb the torque/twist. (Works long enough to get it out of the factory and
past the free tech visits.) After trying many other approaches to removing
the noise, I used a hose clamp to hold an upper spring support at the side
of the trapwork tube, made a shallow hole in the bottom board at the correct
position, and moved the spring sideways to put it in line with the force and
load. Problem solved, at least until the fulcrum bracket fails.

John Ashcraft


On Fri, Nov 12, 2010 at 8:28 AM, Ryan Sowers <tunerryan at gmail.com> wrote:

> This is one part of piano manufacturing I just don't understand. I service
> 100 year old uprights with simple wooden trapworks that work smoothly and
> noiselessly. These modern metal trapwork systems are a constant source of
> problems - it seems that every tiniest noise is greatly amplified, and
> sometimes transmitted through the parts making it very difficult to isolate
> the source.
>
> The plastic spring cups break, the bushings wear out, the rubber grommets
> squeak and wear out prematurely, the brackets seem to click, etc. This is
> one example of "they don't make them like they used to" and its a sad thing!
> It seems like Yamaha went with this system and then every other Asian
> manufacturer followed suit.
>
>
> On Fri, Nov 12, 2010 at 5:52 AM, Barbara Richmond <piano57 at comcast.net>wrote:
>
>> Scratchy sound?  What part is doing it?
>>
>> On Yamahas there is a nylon (or whatever it is) spacer/nut on the prop
>> under the pedal that can squawk.  No amount of lube will help.  You need to
>> detach the pedal from the bottom board, detach the pedal prop from the
>> lever.  Put a leather punching--lubed with your favorite grease--between the
>> nylon nut and the pedal.  Reassemble.
>>
>> That's the fix for that squeak.
>>
>> Barbara Richmond, RPT
>> near Peoria, Illinois
>>
>>
>>
>> ----- Original Message -----
>> From: "Richard Ucci" <richarducci at comcast.net>
>> To: pianotech at ptg.org
>> Sent: Friday, November 12, 2010 7:10:13 AM
>> Subject: [pianotech] Noisey pedal bracket
>>
>> List, I know this has been covered before , but...
>> How do you eliminate that scratchy sound on Asian uprights when the
>> sustain pedal is played?
>> What is the procedure used? Remove brackets and lube with pianotech
>> glide stuff?
>>
>> Rick Ucci/ Ucci Piano
>> www.uccipiano.com
>>
>>
>
>
> --
> Ryan Sowers, RPT
> Puget Sound Chapter
> Olympia, WA
> www.pianova.net
>
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