Pianos on curved church floors

[Dean May]

A piano supported on three points, such as a grand, should be unaffected by
the contour of the floor, as long as the piano remains reasonably level. 

 

One man's opinion.

 

Dean

Dean May             cell 812.239.3359 

PianoRebuilders.com   812.235.5272 

Terre Haute IN  47802

 

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Jessica Masse
Sent: Thursday, May 22, 2008 4:32 PM
To: pianotech at ptg.org
Subject: RE: Pianos on curved church floors 

 

I have been taking care of a C7 Yamaha in an old Presbyterian Church with
curved floor.  It has a complete climate control system properly
functioning.  I have had much trouble with climate stability in this room
but now that the two churches sharing the piano have made sure the piano's
floor length cover gets replaced in between uses the changes seem less
dramatic.

 

However there seemed to be damper problems in the spring summer months.  The
damper tray goes from lifting all at once to being to fast in the middle.
Today I went to tighten tray screws and found them all so-so.  So I
tightened them all and the sustenuto rail screws. In doing so with the tray
screws I tried to force the tray level.  The dampers at both ends still lift
too soon.  But also a few dampers in the middle seem not to seat properly.  

 

Remember this piano is on a curved floor and from Bass end to Treble end I
figure it tilts 1-9/16".  I used silk thread tied to gram weights as a plum
bob measured down the rim was (5-16th for 12-3/4") Piano leans to the Bass
end.   Two things visually can be seen the trichord felt is sliced a bit off
centre, the other is that the flat felt has drifted to the bass end and is
almost missing the right string.  Testing the strings by plucking the bass
side was bleeding through.  I'm figuring I am seeing excessive depression
and poor centering of the dampers in the tenor C#-4 and D#-4 both trichord
felts on the back of damper head wouldn't fall down completely between the
strings only on soft blows but dampen okay on a harder blow they seem to
work okay with the pedal (no hanging up).

 

I replaced the trichord felt only on D#-4 (the most offensive one) and
rebent the wire to pull the flat felt back to centre position (bent at the
top two bends closest to the head) so that the flat felt would cover the
right string.  I made sure that the wire was free enough through the guide
rail and I leveled the strings.  It dampens better now. 

 

On the C#-4 I just made sure the wire was free and the timing was okay.  I
didn't even notice when I started today that this one was a problem.  I
didn't get this one working as well as it should be. 

 

What I will have to do is replace all the trichord felt and centered and
space the wires for the notes with combined trichord and flat felt.   The
remaining 3 notes in the top of the tenor are flat felt on both front and
back of the heads.  These are not working properly either.  The right
strings are almost cleared.

 

The damper wires are nickel plated and they show a black line (can be easily
wiped off) where they contact the guide bushing.  The bushing cloth is very
heavy.

 

There are two things that seem wrong here.  There are very noticeable
compression ridges in the sounding board and I wonder if the belly rail is
affected too causing the damper guide rail to rise and the dampers to go
uneven in the middle and also for them not to rise and fall less far because
the strings might move up too.  (if this were true wouldn't the dampers
track to the right string but maybe because the guide rail moves to the
right the angle change forces the damper to the left.  I know that these
things are all corrected by winter and I can't be by the piano's side to
make sure it keeps getting covered up.  (The easiest thing to do in all
these cases is to ream the guide rail hole more.  But I hate too much
movement in the dampers all that extra noise and it won't fix the pacing
problem.

 

I am wondering has anyone else had gravitational/friction problems with
grands on curved floors?  Could this effect the wear on keys and dampers and
action centre pins?  Doesn't it make sense to level out a piano than run
these risks?  

 

To be honest they had built a leveling stage that rolled around (Chrysler
engineer is a parishioner).  Then, they removed the piano from the stage.  I
think the piano functioned better on the stage.  I am recommending that they
level out the piano before I go through all the work on the dampers.

 

Jessica Masse

RPT Piano Technicians Guild

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080522/3ac9125f/attachment.html