bowing keyframe

[David Ilvedson]

This is what I was getting at in my previous post to Elliot.  You need to
turn up the balance rail glides before you do any front rail bedding.

David I.

> -----Original Message-----
> From: owner-pianotech@ptg.org [mailto:owner-pianotech@ptg.org]On Behalf
> Of Tony Caught
> Sent: Tuesday, October 10, 2000 5:47 AM
> To: pianotech@ptg.org
> Subject: Re: bowing keyframe
>
>
> Hi Elliot
>
> Don't get me wrong when I ask if the keyframe is really bowed or not as I
> seem to get the message that you are not sure.
>
> It may well be that some one in the past has adjusted the balance rail to
> high in the middle and this is causing the front rail to lift in
> the middle,
> or the hold down thingees on the key blocks at the ends may not
> be adjusted
> down and the balance rail may be too high at the ends.
>
> Its hard to tell from your description but I remember back into
> the distant
> past were I came across a piano with a similar problem.  The
> answer in that
> instance was that moths had eaten out all the balance felts and
> some "piano
> tuner" decided to just jack up the balance rail to increase the
> key dip. The
> key block Thingees were loosened but not enough. The combined result was
> that this caused the false appearance of what you describe.
>
> Check it out before proceeding with  the other cures. Check you
> key dip and
> felt thicknesses. If the front touch felts have been changed and
> the balance
> rail has been lifted to compensate a narrow key dip it could also
> cause the
> same problem.
>
> Try to find the reason before proceeding with a cure.
>
> Regards
>
> Tony Caught ICPTG
> Australia
> caute@optusnet.com.au
>
> >     I could not bed the keyframe it either bows in the middle
> or the ends,
> I
> > can't remember which.  No small sanding of the frame could help.  I am
> > wondering if this was ever done deliberately by the factory?  What could
> > have caused it to warp?
> >     Have any of you had this type of experience?  Aside from
> sanding, what
> > is recommended to make the frame more level?
> >
> > Thanks,
> >
> > Hoping to make more improvements on this next week.
> >
> > Eliot
> >
>
>