[pianotech] Young Chang Growing Brackets

Will Truitt surfdog at metrocast.net
Wed Jan 28 02:59:45 PST 2009


Hi Joe:

 

Yes I  did check the bedding and it did need correcting, but my issues
remained before and after, although the bedding obviously affects the dip.  

 

Once I get serious about regulating the action, I will do test notes at the
ends of each section, and then decide where I want the blow distance to be.


 

I can get enough dip by simply removing punchings, and there are enough on
the rails to do that.  So I have the option of controlling aftertouch in
both ways.  

 

Thanks.  

 

Will

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Joe DeFazio
Sent: Wednesday, January 28, 2009 3:41 AM
To: pianotech at ptg.org
Subject: [pianotech] Young Chang Growing Brackets

 

Hi Will,

 

I am no action ratio genius, but here is my contribution anyway.  I am going
to throw out question which you probably thought of and addressed already,
but just in case you didn't:  did you bed the keyframe or check the keyframe
bedding?  As I'm sure you know, this can affect key height and key dip
(among other things), sometimes in unpredictable or relatively extreme ways.
Probably not it, but worth a minute to check, especially the glide bolts.

 

If everything else is working, would you consider compromising by shortening
the blow distance just a bit?  After all, folks rarely complain that their
Young Changs are not loud enough.  That would help you to more easily
achieve a key dip with enough aftertouch, and would allow you to position
the hammer rest rail in a more comfortable spot.  You wouldn't have to bury
the capstans as much, either.  I usually prefer to slightly adjust a couple
of parameters so that "everybody gets along" instead adhering to a setting
in one place that pushes other parameters near their extremes.

 

Thanks for describing your brass action spread setter/gauge -  I'm going to
remember and use that method in the future!

 

Good luck with it,

 

Joe DeFazio

Stillertown

 






-----Original Message-----
From: Will Truitt <surfdog at metrocast.net>
To: pianotech at ptg.org
Sent: Tue, 27 Jan 2009 2:20 pm
Subject: [pianotech] Young Chang Growing Brackets

To the List:

 

I am hoping to get a little bit of advice from my action ratio genius
friends on the forum.  I have  a Young Chang G-150 which I have gotten and
installed new action brackets to replace the old growing problem brackets.
As best I can tell, this piano was built in early 1992, which would put it
on the cusp between two action spread values of 112.5 and 113.5 mm.  The
spec sheet from Young Chang which I got some years ago says, "Action spread
should be set to 112.5 mm.  Models newer than 1992 = 113.5 mm."  I took that
to mean that pianos made after 12/31/92.  Which probably means that this
piano should be set at 112.5 mm.  But it is a little ambiguous, and I have
been trying to call  Derrick Cornejo at Young Chang for the past few days
for clarification, but he is MIA, his mailbox is full, EVERYBODY's mailbox
is full, and even the operator is missing!

 

I set the spread at 112.5 yesterday.  This I did by taking a thin piece of
1/8" brass stock, and carefully drilling two holes in it at exactly 112.5 on
the drill press, and then installing two .050 center pins through these
holes.  Removing the shanks and whippens from their flanges at the ends, I
screwed the flanges to the rail.  Then I loosened the whippen rail screws,
and moved that rail back and forth until the two center pins would go into
their respective holes in the flanges.  I then tightened the whippen rail
screws, locking in the action spread at that position.  So I am pretty
confident that I have been very accurate at setting the spread at 112.5 mm. 

 

I also needed to retap the screw holes in the rails, as the old screws would
not go in very far.  Once I did that, they turned nicely.  I also had to
plug and redrill the holes in the keyfram that screw the stack to the
keyframe, as the two center brackets did not line up with the old holes.
And longer screws for the taller bracket feet.  No worries here.

 

I took the action back to the piano today.  Installing it, the hammers were
still blocking against the strings.  However, when I set the hammer drop f
ar enough away to be sure to get let off, I was able to back off the let off
screws and achieve proper let off on several test notes.  I set the drop
then.  I had already set the jack height and position in the window. 

 

The anomalies here are thus:  I was just barely achieving cycling through
let off, with little or no aftertouch, without removing front rail
punchings.  The manual asks for 64.5 mm key height (which the piano was
properly set at).  I was getting about 9.4 to 9.6 mm key dip, and could
achieve the 10.2mm  by removing cardboard punchings.  And it feels ok.  I
set the hammer blow distance at the factory spec of 47mm, but had to LOWER
the capstans to achieve 4 or 5 mm to get it down to that value.  At which
the bottom of the shank is sitting about 3/16" above the hammer rest rail
felt, which is adjustable and at its lowest setting at that point.  The
bottom of the let off rail is sitting about 1/8" above the back edge of the
whippen.  So everything is working, but there is not much room. 

 

I also took touch weight readings on two notes:  Note 27 was 55 g. DW, and
29 g. UW.  Note 88 was 53 g. DW, and 36 UW.  (These test notes had been
regulated).

 

At first I was wondering if the plate was set too low.  I didn't have my
string height guage with me, but I was able to get a string height at note
77 of about 198 mm. 

 

But I think the hammer bore is sufficiently accurate to the string height.
Note 1 was bored at 57 mm, note 27 at 51 mm, and note 88 at 49.5 mm.  There
is very little wear on the hammers.  At let off, the test notes shanks are
parallel to the string plane, not over or undercentering to any degree.
And, with the hammer blow distance set at 47 mm and the jack position in the
window adjusted to line up the back of the jack to the back of the knuckle
core piece, they form a straight line.  At let off, the bottoms of the
hammer tails are even with the tops of the back checks.  All of these things
are good signs for action set up.  Capstans are centered under their
cushions.

 

At least on my test notes, it seems like the piano is going to regulate ok.
It FEELS ok (for a Korean piano)

 

The only thing that is holding me back is the fact that I am having to lower
the capstans to achieve the 47 mm blow distance, and remove punchings to get
the 10.2 mm dip (which yields plenty of aftertouch).  That part is odd, but
I am assuming that the piano was set to the correct values for blow and dip
at the factory way back when. 

 

The essence of it is that if I decide that I need to change the spread after
I have regulated the action, the values I have set will go out the window
and need to be done over again.  So I want to be right the first time.

 

So what will it be, boys and giris - is your antenna going up, or does
everything seem hunky dory and I should keep the spread value of 112.5?

 

Thanks for your contribution.

 

Will Truitt

 

 

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From: Ryan Sowers <tunerryan at gmail.com>

Date: January 28, 2009 2:19:04 AM EST

To: pianotech at ptg.org

Subject: Re: [pianotech] Grand Mute Rail

Reply-To: pianotech at ptg.org



It actually looks like a very clever product. I'm looking forward to seeing
it at the Cal Sate conference. It's about time someone came up with a
practical muting system for grands. 

On Tue, Jan 27, 2009 at 5:17 PM, William Monroe <pianotech at a440piano.net>
wrote:

Al,

 

www.grandpianomuffler.com

 

WRM

SNIP

 

Who sells the grand mute rail/system?

 

Al




-- 
Ryan Sowers, RPT
Puget Sound Chapter
Olympia, WA
www.pianova.net




From: David Andersen <david at davidandersenpianos.com>

Date: January 28, 2009 2:44:28 AM EST

To: pianotech at ptg.org

Subject: Re: [pianotech] Young Chang Growing Brackets

Reply-To: pianotech at ptg.org





On Jan 27, 2009, at 4:20 PM, Will Truitt wrote:





The only thing that is holding me back is the fact that I am having to lower
the capstans to achieve the 47 mm blow distance, and remove punchings to get
the 10.2 mm dip (which yields plenty of aftertouch). 

So what? If everything works, and clears, you're good. 47mm blow and 10.2 mm
key travek is about  is about ideal. With a Balance Weight of 42, it's a
little stout for my taste; maybe that can be helped with lubrication, close
checking, and agressive distal jack position (moved toward the player.)

 





That part is odd, but I am assuming that the piano was set to the correct
values for blow and dip at the factory way back when. 

Bad assumption, and remember: specs are a guide only. Each action is custom.

 

David A.




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