Pianotech

Has anyone experienced an unusually high number of bass string breakage on Kawai KG-6C (circa 1980)? There is a 40 to 45 degree angle in the counter bearing section I suspect in contributing to the high breakage rate.

Roger

------------------------------
Roger Gable RPT
Gable Piano
Everett WA
(425) 252-5000
------------------------------

Hi, Roger,

Yes, also on the KG-5C.

In addition to the counterbearings, I've also found the breakage seems partly to have to do with over-hardened hammers; and, thus far, pianos that are often "overplayed" (AKA "pounded").

Perhaps this is a series that might benefit from some rescaling. One problem that I can see with that approach is that many of the clients I've had who own these things _really_ that big, bold sound. Maybe there's a compromise.

Thanks for mentioning this. I've got another KG-6C to look at for a good deal of work...might as well start thinking about it.

Kind regards.

Horace




  Original Message

Jim Harvey, when with Kawai, told of a gentleman in a church who said "I could break that" after Jim had finished putting in a warranty string. He proceeded to show how his bass octave tremolo snapped it. Something about amplitude-matching, whatever. To me: still 'hard hammers', 'pounding', etc. Unsolvable. Just take away their let-off, which is an imperfect solution, too.

------------------------------
David Patterson RPT
Richmond Hill ON
(416) 638-0901
------------------------------

Original Message:
Sent: 10-06-2023 16:35
From: Horace Greeley
Subject: Kawai KG-6C bass string breakage

Hi, Roger,

Yes, also on the KG-5C.

In addition to the counterbearings, I've also found the breakage seems partly to have to do with over-hardened hammers; and, thus far, pianos that are often "overplayed" (AKA "pounded").

Perhaps this is a series that might benefit from some rescaling. One problem that I can see with that approach is that many of the clients I've had who own these things _really_ that big, bold sound. Maybe there's a compromise.

Thanks for mentioning this. I've got another KG-6C to look at for a good deal of work...might as well start thinking about it.

Kind regards.

Horace




  Original Message

I don’t agree that increasing let off will lead to less string breakage. When people who pound pianos encounter less power in the keystroke, they pound harder. I have seen many instances, particularly in churches where the let off is quite far away and still lots of string breakage. I believe a well-regulated piano with correct let off leads to less damage on the piano, strings included.

Perhaps the very steep counterbearing angle is stressing the segment between counterbearing and tuning pin and leading to breakage there. Is it possible to reduce the angle? Unless that leaves the string coils too close to the plate.

Joe Wiencek
NYC


Original Message:
Sent: 10/7/2023 11:50:00 AM
From: David Patterson
Subject: RE: Kawai KG-6C bass string breakage

Jim Harvey, when with Kawai, told of a gentleman in a church who said "I could break that" after Jim had finished putting in a warranty string. He proceeded to show how his bass octave tremolo snapped it. Something about amplitude-matching, whatever. To me: still 'hard hammers', 'pounding', etc. Unsolvable. Just take away their let-off, which is an imperfect solution, too.

------------------------------
David Patterson RPT
Richmond Hill ON
(416) 638-0901
------------------------------

Horace and Jim,

I failed to mention that the strings are breaking at the tuning pin not the agraffe so the hard hammer theory wouldn't support the hammer issue.

Roger 

------------------------------
Roger Gable RPT
Gable Piano
Everett WA
(425) 252-5000
------------------------------

Original Message:
Sent: 10-06-2023 16:35
From: Horace Greeley
Subject: Kawai KG-6C bass string breakage

Hi, Roger,

Yes, also on the KG-5C.

In addition to the counterbearings, I've also found the breakage seems partly to have to do with over-hardened hammers; and, thus far, pianos that are often "overplayed" (AKA "pounded").

Perhaps this is a series that might benefit from some rescaling. One problem that I can see with that approach is that many of the clients I've had who own these things _really_ that big, bold sound. Maybe there's a compromise.

Thanks for mentioning this. I've got another KG-6C to look at for a good deal of work...might as well start thinking about it.

Kind regards.

Horace




  Original Message

Original Message:
Sent: 10/7/2023 12:58:00 PM
From: Roger Gable
Subject: RE: Kawai KG-6C bass string breakage

Horace and Jim,

I failed to mention that the strings are breaking at the tuning pin not the agraffe so the hard hammer theory wouldn't support the hammer issue.

Roger 

------------------------------
Roger Gable RPT
Gable Piano
Everett WA
(425) 252-5000
------------------------------