[pianotech] ever changing hammer line response

Paul T Williams pwilliams4 at unlnotes.unl.edu
Mon Nov 3 05:37:53 PST 2008


Hi John,

Good point about the uneven key tops.  My test isn't nearly 10mm.  Just 3 
or 4mm. This is how Steve Brady taught me. Did anyone mention a 
possibility of really tight wip flanges not allowing the action to come to 
rest? or hammer flanges? The more I think about it, the more I think of 
humidity problems..I think Ron mentioned something about that early on...

I just went to a Steinway action here in the shop and lifted just the back 
of the key...the fronts did go down a bit, the center of the key a bit 
more (as if they were hanging up on the pin) and the hammer way up. But if 
these are happening on the sharps, one might not notice the change in 
front key height much...Indeed a good puzzler! Why wouldn't they all do it 
if the BR holes are too tight?  Perhaps the BR's are just at the point of 
being too tight, but just tight enough to become more apparant in the 
sharps...I'm waiting for the "real" answer!! I gots to know....

PW




"John Formsma" <formsma at gmail.com> 
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11/02/2008 03:53 PM
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Re: ever changing hammer line response






On Sun, Nov 2, 2008 at 1:49 PM, Paul T Williams <
pwilliams4 at unlnotes.unl.edu> wrote:

 Tight balance rail holes can alter lots of things....If they don't always 
settle down, freely, to the BR punchings, your hammer line will indeed be 
off...Slightly lift your keys and see if they fall right back...if 
sluggish, then there's a problem.

 
I'm certainly no expert, and am merely repeating what is taught in 
Yamaha's 37 Steps.

The balance hole, according to Yamaha, should be tight enough so that when 
the key is lifted about 10 mm, it does not return on its own.

If the BR holes are too tight, how do they work themselves up a BR pin? 
I'm trying to visualize how that would happen when there is the return 
force on the capstan from the whippen, the lead in the front part of the 
key, the key stop rail in proper position, and the BR pins angled slightly 
backward.  I'm not disputing here -- just trying to learn some more.

Plus, wouldn't you also see obviously unlevel keys in such a case? And 
would it cause uneven hammer line of the 1/2 inch that Tom mentioned?

-- 
JF
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