observations and stuph

Ron Nossaman RNossaman@cox.net
Tue, 10 Jun 2003 19:23:25 -0500


Yesterday afternoon, I did a little prep on a Pearl River grand for a local 
dealer. It was intended as a replacement for a case damaged one of the same 
I had serviced (un-prepped) in the customer's home a couple of weeks ago. I 
had spent an hour or so chasing shift squeaks and other odd noises on the 
first one, and found myself doing the same on the replacement.

The shift lever in this piano has a built in mounting hinge and is recessed 
into the underside of the keybed. The lever assembly had been carefully 
positioned so that the lever end that the pedal rod pushes up on, was 
wedged firmly against the side of the recess it was mounted in. This 
guaranteed a very loud SQUAWK every time the pedal was depressed. I decided 
to start there.

After dropping the lyre, relocating the shift lever mount, gluing/wedging 
in place in the recess I enlarged a tad to allow this, replacing two of the 
three too short (I thought) screws with some a bit longer, and replacing 
the lyre, I pushed the pedal again. Squeak!

I pulled the action and made a discovery. First, the shift lever ear that 
engages the keyframe is rough cast with sharp corners. Second, the slot in 
the keyframe has no hardwood (select or otherwise) for the shift lever to 
push against. It's just nice softwood end grain, and already obviously 
crushed. If it had been in the shop, I'd have added the hardwood. As it 
was, I filed the shift lever ear smooth, and rounded the corners some, 
applying a touch of VJ as squeak repellant. Action back in. Depress pedal. 
Criiiick!

Action back out, and more discoveries. The shift guides in the cheek blocks 
don't fit the guide pins. Lots of slop. The dags are light gage formed 
sheet steel, lined with bushing cloth, and the action seems to be located 
fore and aft by two capstans in the back of the keyframe riding the inside 
of two of the dags on the keybed. Fine, I suppose, but the capstans were 
protruding some distance out of a couple of overly deep recesses cut into 
the back of the keyframe, and they cricked as they slid along (and dug 
into) the cloth on the dags. More VJ. Action back in. Pedal down.

More squeaks, sqicks, cricks, ticks and creaks. Pulled action. Pencil 
graphite glide bolt platform inserts, lube shift return spring contact 
area, sand keybed and teflon powder. Action in, pedal down... silence. No! 
Surely something else is at least trying to squeak. But no, or if there 
was, I couldn't find it. On to tuning.

What's that sound? Maybe it's just me (not the sound, the attitude), but it 
seems only right that a new piano should have positive bearing even in the 
killer octave. Perhaps I'm just being too picky, since so many much higher 
priced instruments don't, but it seems such a shame and a waste to put all 
those natural resources and man hours into something without meeting 
reasonable minimum performance standards. As I said, perhaps I'm just too 
picky and positive bearing in the killer octave is an unreasonable 
expectation as well as a somewhat less than universal condition.

Also, a back scale in the 20mm range through the top two sections, and not 
a lot more than that down through the tenor doesn't leave much margin for 
error, or even normal soundboard deflection and settling - not to mention 
function. The odds of achieving and maintaining positive bearing go up 
dramatically as the back scale is lengthened, even if you don't change 
anything else BUT the back scale length. The concept ain't rocket science, 
even though lots of things besides back scale length could use some changing.

By the time the tuning was done, so was I. The piano isn't concert ready, 
but it's combat ready, which is all they were after.

Next!

Ron N


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