Action flange crushing <outside>

[David M. Porritt]

Phil:

Back in 1993 we bought 40 new Baldwin 243HPs for practice rooms.  About 1996 I was given a work-study kid who didn't like any of the other assignments he had been given so they decided to give him to me.  He was a percussionist of rather surly demeanor.  I thought that even he could tighten the hammer flange screws on these, now 3 year old pianos.  I showed him how to "snug" them but not over tighten them.  

I thought that I had success with him that had eluded the other supervisors.   Later when I encountered many loose, wobbly hammers my first thought was that he hadn't sufficiently tightened the screws.  I quickly learned that in actuality he had crushed them so badly that the bushed parts had spread out and many had split in two.

Moral:  Never try to get real work from a surly student percussionist!

dave

__________________________________________
David M. Porritt, RPT
Meadows School of the Arts
Southern Methodist University
Dallas, TX 75275
dporritt@mail.smu.edu


----- Original message ---------------------------------------->
From: Phillip Ford <fordpiano@earthlink.net>
To: Pianotech <pianotech@ptg.org>
Received: Wed, 17 Nov 2004 08:24:41 -0700
Subject: Re: Action flange crushing <outside>

>>Phil,
>>I am already 6'3" please let go of my leg. <G>
>>Crushed flanges have the habit of breaking in the screw hole.
>>Joe Goss RPT

>No sense in having one leg longer than the other.  Might as well pull 
>the other one.  Soon you'll be ready for your next career in the NBA 
><G>.

>This is the conventional wisdom.  Would you expect the part to break 
>right away or some time down the road?  I've taken several new 
>Steinway flanges (both Steinway and equal), which I would consider 
>the easiest to break, and torqued them on a Steinway rail until there 
>was very definite crushing, with no sign of breakage or cracking. 
>Perhaps I put in an invisible flaw which would cause failure of the 
>flanges years later, I don't know.

>Also, assuming that you torque the screw until the flange was just on 
>the verge of crushing, what do you think would happen over time?  I 
>suppose it depends on the humidity when you did the installation. 
>But it seems quite conceivable to me that if you had a major change 
>in humidity from the installation level then the flange is going to 
>swell and be crushed.  If this is in fact going to damage the flange 
>then perhaps the screw shouldn't have been put in that tight to begin 
>with.

>Regards,

>Phil Ford
>_______________________________________________
>pianotech list info: https://www.moypiano.com/resources/#archives