Hammer height conundrum on a '46 Hardman grand

[Dean May]

George,

The answer to your question is not as cut and dried as you would like for it
to be. You are delving into an area that took me 10 years to realize there
was more going on that I had thought. And I am still learning, as many of us
on this list are. So what you are asking us to share with you in a few short
paragraphs is something that has taken me 25 years to learn.

You are wanting specifications that you can measure and adjust (don't we
all). When it comes to regulating grand piano actions, the specs really only
get us a starting place, especially when working on an old piano such as
yours where the specs you have may be suspect. It is our challenge to
balance all of the specs in a way that will get us close let off, adequate
blow distance, good repetition speed, and, perhaps most importantly,
sufficient after touch.

With the symptoms you have described, I would probably try increasing the
blow distance to 1 7/8 or 2", making sure I could get close let off and have
sufficient after touch. Before you do this, of course, you need to make sure
your foundation is good, i.e., keyframe bedded, keys leveled, key adequate
dip.

The Amazon link to the Reblitz book Ric referenced is:
http://www.amazon.com/exec/obidos/ASIN/1879511037/qid=1105534210/sr=2-1/ref=
pd_ka_b_2_1/102-9681584-8821755

You must purchase and read this book if you are at all serious. On my first
restoration project I had spent hundreds of dollars on a new set of hammers
and regulation. The results weren't great but I thought probably the best
that could be accomplished on a 70 year old piano. Using this book and only
tools around the house, I re-regulated my piano and couldn't believe the
difference. Having done only a little research I was able to do so much
better than the guy faking his way through life as a piano technician that
it persuaded me to go into the business. Maybe it will you also. ;-)

Blessings,

Dean May


-----Original Message-----
From: pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]On
Behalf Of George Whitty
Sent: Wednesday, January 12, 2005 12:35 AM
To: Pianotech
Subject: Re: Hammer height conundrum on a '46 Hardman grand


After a long, careful examination of my piano (and my assumptions about
my piano), I've come to the conclusion that my hammers have been filed
several times.  They're actually faceted, some in a fairly lumpy,
asymmetrical way, and looking really closely I can see and feel two
distinct rounds of filing, with possibly more;  This is probably where
I'm losing most of that 3/16".   I'm not in any position to replace the
hammers in this piano for now;  that one's WELL beyond my scope, so I'm
looking for the best compromise.  It occurs to me that by shimming with
a couple 1/16" washers beneath each of the 8 support posts on the upper
structure of the action (thus raising the hammers 1/8") , then turning
up the capstans and adjusting the backchecks (these were going to need
a regulation anyway), I could at least preserve more of the correct
geometry between the wippens and the hammers than I would by simply
screwing up the capstans until the hammer travel is 1 3/4" but the
hammer shanks are sitting way above the hammer rests.  The disadvantage
of this approach is that I have to crank the capstans even higher (or,
as Barbara suggested, fill out the wippen cushions more) to raise the
hammers than I would if I left the upper action where it is, thus
taking advantage of the leverage (in which lifting the wippen a little
raises the hammer a lot).  Has anyone done anything like this?  Is it
just a terrible idea, or a workable kluge until I can pay someone to
replace all the hammers one day?

Thanks again,
George


> Hi, Mike:
>
>    Thanks for the reply;  I raised the capstan on my middle C to get
> the
> hammer 1 3/4" from the bottom of the string and took some measurements
> (didn't have time to do more keys today).  Here's what I end up with:
> from
> the cushion to the shank is 5/16", the hammer bore is 1 31/32", and the
> distance from the hammer to the bottom of the strings is now 1 3/4".
> I took
> a look at a couple pianos today, a Steinway and a Yamaha, and their
> hammer
> shanks sit a very neat 1/8" above their cushions the entire length of
> the
> keyboard.  Thus, doing the math, it seems that to achieve that in my
> piano,
> middle C's cushion should sit 1 31/32 + 1 3/4 + 1/8 + half the
> diameter of
> the hammer shank below the strings;  unfortunately that 1/8" in my
> piano is
> a pretty consistent 5/16" or so, which makes me wonder if the whole
> keybed
> is somehow sitting 3/16" too low in my instrument.  For those still
> bearing
> with me, I have a couple questions based on this information:
>
> 1.  I notice that, while there's a good deal of resistance trying to
> push
> the hammer down to the cushion with the jack still under the knuckle,
> it'll
> go right down easily with the jack tripped.  Is the cushion there only
> to
> catch the key if it rebounds too fast for the jack to get back under
> the
> knuckle, in which case I think my keys work fine even with the 5/16"
> gap?
>
> 2.  Could someone enlighten me a bit more as to how to determine
> whether my
> hammers have been filed?  Feeling around the edges of some of them, I
> now
> notice a little very slight ridge, a little angle as though some felt
> had
> been removed (the little ridge sits at about 9:30 and 2:30 on the
> hammer)
> they're definitely not just one totally smooth arc.  I'm just not sure
> whether this is something done at the factory as a way of voicing the
> things
> or something.  In any case, I think they'd look more out of round if
> there
> was 3/16" missing off the tops.
>
> 3.  Is 1 31/32" a typical measurement for a middle C hammer bore, or
> does a
> "typical measurement" even exist?  Is there somewhere that I might
> find out
> what this measurement SHOULD be for my piano?
>
> Thanks again to everyone helping me out with this intriguing problem..
>
> George Whitty
>
>
>> Hi George,
>>
>> As Ric B. mentioned, something does not add up, literally, if the
>> shanks
>> are 1/2" off the cushion when the blow distance is 1 3/4".  The
>> couple of
>> Hardmans that I've seen / worked on have regulated to fairly
>> conventional
>> dimensions.  Picture the virtical distance from the rest cushion on
>> the
>> wippen up to the strings.  It wil be subdivided into 1) clearance to
>> shank
>> at rest, 2) hammer bore length (plus 1/2 shank diameter), and 3)
>> hammer
>> blow distance.  If 1) and/or  3) are larger than they should be, then
>> 2) is
>> smaller than it should be, either by design or through wear.  Let us
>> know
>> what the bore distance is, for several hammers from bass to high
>> treble.
>> Also, take a look at the string grooves - how deep and long are they,
>> and
>> are they perpendicular to the molding ?
>>
>> Mike

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