[pianotech] Kawai puzzler

[Larry T.]

Just a quick thought about why a constrained spring would make the damper
hang up... I think the spring has to slide a little in the groove to keep
the correct alignment of the damper head. A constrained spring would keep
the head at a slight angle. But I could be wrong!!!!!!!!!!!!

Larry Trischetta
Scranton PA

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Koval
Sent: Saturday, January 28, 2012 12:16 PM
To: pianotech at ptg.org
Subject: [pianotech] Kawai puzzler


Some detective work for this Saturday morning:
Piano - Kawai NS-20 - tall upright with one of those split lid fold back
tops.

Complaint - some damper ringing randomly....  Owner couldn't replicate
the problem earlier this month during the regular tuning visit, so I asked
if theycould find out what note(s), during what pieces.
Went back today after I was notified only C4 happened sometimes...
So - noticed an old coffee spill leaked between the split top down onto the
muffler rail and then farther down... right at C4. Piano w/plenty of plastic
parts.
Took out the action, still couldn't make the damper hang...
Reversed it, gently pressing on dampers - C4 felt "different" - harder to
push.
Turns out the spring was glued to the damper lever by the spill.  Along with
a mess on the spoon.
Cleaned, lubed - everything seems fine, but for the life of me, I can't come
up with a reason why a constrained spring would make the damper hang up and
ring???
Hmmm..
Ron Kovalchicagoland
www.ronkoval.com 		 	   		  =