[pianotech] wooden click at letoff?...reprise

Jim Ialeggio jim at grandpianosolutions.com
Fri Jan 4 19:19:03 MST 2013


An unsuccessful followup on this post from November...

Got back back to this 10 year old Renner action with a recalcitrant 
click at and after letoff. There are now 2 of them, F1 & G#1.

I had thought originally that the sound was from the shank assembly, so 
I appeared armed and ready for knuckle changing or shank changing. 
Removed and re-glued both knuckles, then set about putting in a Dampp 
Chaser. Finished the DC and  listen for the click...still there...rats.

Swapped a nearby quiet shank, and carefully regulated the swapped shank 
so I got the full and proper letoff/aftertouch event. The swapped shank 
produced the same click as the original shank. So my original assumption 
that the shank was the culprit was too hastily decided. Started looking 
around.

-F1 had an anamolous geometry issue. JAck was smacking the jack stop 
felt, while all the other notes including  the other offending note, 
G#1, were just fine at the jack stop felt. Removed half the jack stop 
felt from F1...click remained. The jack toe is definitely set at a lower 
angle than the other whips, and jack travel is more than the other 
whips, but it doesn't seem to be the source of the sound, as I removed 
enough felt to leave some clearance.

-looked for flange issues on two whips (turbo). G# cracked on one side 
of the flange, but F1 fine.

-Then in messing around, I lifted the dampers with the pedal, and tried 
both notes again.  This time the click on both notes disappeared! I 
suspected a loose lead in the damper levers. Took out the action played 
with the offending damper levers, but as time was way past up, and had 
to clear out, I couldn't remove the levers to check the weights on this 
visit. In moving the levers there was no noise, but I don't think that 
is a fair indication of anything, since connection to the back of the 
key is their path to the click amplifying keyframe/keybed...though there 
is a felt interface beween damper lever and key which I would think 
would mitigate at least some noise.

Question?...does this sound like the modus operandi of loose damper 
lever weight?  Why would damper lever weights click at and after letoff? 
Let off does impart a kick to the key, which might rouse the offending 
leads, but I'm still somewhat sceptical...but running out of ideas. I 
scheduled a DC followup tuning in 3 weeks, so I have an imminent rematch.

Jim Ialeggio





-- 
Jim Ialeggio	
jim at grandpianosolutions.com
978 425-9026
Shirley Center, MA



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