I read somewhere (where?) that the oblong pins are designed to be turned to adjust the gap. So, why don't the balance rail pins also have the same feature? There are plenty of deeply furrowed balance rail bushings. Turning the pins a little bit isn't going to dig into the bushing, but more than a little bitis going to do that. So if you've got loose keys, it's time to rebush or use Profelt. But fine adjustments are possible if you're looking for consistent clearance. Otherwise, why not just have a flat sided pin? Plenty of bearing surface and less wear on the bushings. I can only surmise this has been hashed out many years ago by the greatest designers and engineers, and it seems to work. Who am I to question tradition?
I also agree with Joel, that cost is likely a big factor. That curbside piano the customer just got probably isn't going to get new bushings, and selling that trade-in for a little more profit by turning the pins instead of rebushing, is tempting.
My thoughts..
Paul McCloud
San Diego
Hello Colleagues
Having just asked (on line) Susan Kline what her thoughts on the front rail key pins are, I thought I had really best put it to the membership.
An ex-client of mine has sent his Bechstein Upright piano for restoration following a deluge. Not an unusual event nowadays. The piano is a 1912 Model 10 and he is worried about the keyboard - looseness of the keys following the restoration. The person at the Piano Restorers says:
In all piano keyframes, these front-rail guide-pins are oval/elliptically shaped for the very purpose of enabling some sideways movement to be eliminated.
With which I disagree and believe the purpose for the ellipsoid cross section is to give a larger bearing surface and that to turn these pins in some form of regulation to get rid of sideways motion defeats the original purpose and will cause even greater wear.
Your thoughts please - the restorers are biting at the bit for payment!!
Michael Gamble UK 15 July 2021
------------------------------
Michael Gamble
semi retired
Brighton
01273813612
------------------------------
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Original Message:
Sent: 7/15/2021 10:32:00 AM
From: Joel Weber
Subject: RE: Front Rail Pins in the Key Frame
Over the years I've seen plenty of turned key pins, evidently to remedy loose bushings.
It seems to work for a while, though in the end the correct repair is to replace the bushings.
Usually cost seems to dictate either turning the pins or replacing the bushings (er even installing
new pins). As to the design, I've never heard a theory advanced and wonder if tradition keeps them
oblong, or the larger surface area is more desirable to spread out friction and keep from digging a
rut or channel into cloth?
Original Message:
Sent: 7/15/2021 8:22:00 AM
From: Michael Gamble
Subject: Front Rail Pins in the Key Frame
Hello Colleagues
Having just asked (on line) Susan Kline what her thoughts on the front rail key pins are, I thought I had really best put it to the membership.
An ex-client of mine has sent his Bechstein Upright piano for restoration following a deluge. Not an unusual event nowadays. The piano is a 1912 Model 10 and he is worried about the keyboard - looseness of the keys following the restoration. The person at the Piano Restorers says:
In all piano keyframes, these front-rail guide-pins are oval/elliptically shaped for the very purpose of enabling some sideways movement to be eliminated.
With which I disagree and believe the purpose for the ellipsoid cross section is to give a larger bearing surface and that to turn these pins in some form of regulation to get rid of sideways motion defeats the original purpose and will cause even greater wear.
Your thoughts please - the restorers are biting at the bit for payment!!
Michael Gamble UK 15 July 2021
------------------------------
Michael Gamble
semi retired
Brighton
01273813612
------------------------------