Front lid extended during performance

[David Love]

I'm not sure why this is such a big deal.  When you close the front part of
the lid while the lid is propped, the left hand side of the short lid
contacts the rim of the piano preventing it from hyperextending and
stressing the hinges.  In addition, the thickness of the lid itself means
that the underside of the front and rear part of the lid will be in contact
with each other when in the closed position also preventing hyperextension.
If the screws are of reasonable quality and they penetrate to a reasonable
depth, there shouldn't be any problem with this.  Normal expansion and
contraction of the wood will likely cause the screws to loosen up and
require periodic tightening no matter what.  More often than not, it's when
the periodic tightening is not done and the lid is opened and closed with
screws that are no longer solidly bedded that starts the ball to failure
rolling.   I don't see this particular practice of closing the front part of
the lid when propped putting any more stress on the hinge than the simple
act of opening and closing the lid in the normal manner.   If a problem
arises, it would likely have arisen no matter how the lid was opened and
closed and is most likely due to inadequate design or maintenance, not the
manner in which the lid is placed when propped.    

 

Hanging or pulling on the lid (I assume you were being facetious) will, of
course, push the design beyond its limits and is not a fair test.  

 

David Love
davidlovepianos at comcast.net
www.davidlovepianos.com 

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of paul bruesch
Sent: Monday, January 07, 2008 2:22 PM
To: Pianotech List
Subject: Re: Front lid extended during performance

 

I wouldn't bother referring them to anyone. Hinges are simply not designed
to support a load in that position. Not even piano hinges. If they insist
they have to always have it open in that configuration, you or a carpenter
should design a proper means of stiffening the joint so as to relieve the
stresses from the hinge. If they (the owner(s)) disagree, then challenge
them to prop the lid open the way they like it and hang/pull on the closed
front. Be sure to be standing a ways back so they don't fall into you when
the hinge/screws fail(s). (I'm kidding... don't even suggest that because
some people will do it... and then make you fix it... and charge you for the
hospital bill.) 

Think about it. Would you remove the stop from your bathroom door and then
move the door beyond its closed position? No. That kind of leverage would
rip the screws right out. Ever noticed how a hydraulic storm door closer
typically has a safety chain/spring to prevent the door from leveraging its
bracket out when you open the door all the way? 

Paul Bruesch
Stillwater, MN

On Mon, 07 Jan 2008 16:05:01, Don <pianotuna at accesscomm.ca> wrote:

Hi Carmen,

I would refer them to the manufacturer of the instrument, or the store they
purchased it from, and would suggest that it may overstress the tiny wood
screws. If they choose to do it anyway then you can be happy to repair it 
for them at some future date.

At 12:16 PM 1/7/2008 -0800, you wrote:
>
> My colleagues,              if they ask me whether the front lid IS or  IS
>NOT designed to tolerate that configuration?           -piano 
>manufacturers- or factory reps as to whether the front lid  was -designed-
>to be extended when the main  lid is propped up.   Carman Gentile RPT
Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T.
Non calor sed umor est qui nobis incommodat

mailto:pianotuna at yahoo.com      http://us.geocities.com/drpt1948/ 

3004 Grant Rd. REGINA, SK, S4S 5G7
306-539-0716 or 1-888-29t-uner

 

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