observations and stuph

[Joe And Penny Goss]

Hi Ron
I had a similar time with a Samick. It turned out to be a combination of
dried grease on the return spring and mostly the dag adjustment screw biting
into the back side of the action wood.

Joe Goss
imatunr@srvinet.com
www.mothergoosetools.com
----- Original Message ----- 
From: "Ron Nossaman" <RNossaman@cox.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Tuesday, June 10, 2003 6:23 PM
Subject: observations and stuph


> 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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