Knabe Bridge Repair

[Erwinspiano@AOL.COM]

---------------------- multipart/alternative attachment
In a message dated 4/6/2002 2:00:50 PM Pacific Standard Time, 
garylteters@prodigy.net writes:


> Subj:Knabe Bridge Repair 
> Date:4/6/2002 2:00:50 PM Pacific Standard Time
> From:<A HREF="mailto:garylteters@prodigy.net">garylteters@prodigy.net</A>
> Reply-to:<A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
> To:<A HREF="mailto:pianotech@ptg.org">pianotech@ptg.org</A>
> Sent from the Internet 
> 
> 
> Gary

     >>>>>>..nabes are notorious for cracking /split bridges
> Long time listener, second time caller. I'm moving a little deeper in my 
> piano work. I've mainly been working on my tuning skills and minor piano 
> repair and regulation. While I'm sure this will be minor to most of you 
> it's new to me. 
>     The piano in question is from the 1890's.  Knabe grand, 6'1" with a 
> third bridge riding piggyback  on the treble bridge near the lower end . 
> Ser#38068 or so. I'm repairing small cracks in the bridge. I would like to 
> sand the upper surface to remove the string grooves, renotch and epoxy in 
> new pins. I noticed on this piano that the pins holes on the speaking side 
> are set at the edge of the notch, so the pin actually is completely  off 
> the top of the bridge. The notch does not run through the center of the 
> holes, it just plain misses them all together.

>>>>>>>>>>I've seen many of these types of configurations and they seem to 
work. I've also seen a vertical cut straight down about 2mm thru the center 
line of the bridge pin holes .The idea being that as the string sinks lower 
into the top over time that the stings won't also creep forward which they 
will over time and tooo much string seating. Because of the vertical cut they 
simply sink lower against the pin but maintain termination. On bridges that 
the notches were cut too shallow on the string can actually be damped by 
ttouching the wood in the notch as it creeps forward. Hey time marches on.
        Also as you sand down the bridge top just remember that the farther 
down you go the less and less your bridge pin side bearing will be and  many 
Knabes didn't have that much to start with.

> .  The pins on the back side are drilled to set completely on the upper 
> surface of the bridge, just inside the notch. Sort of like it was all done 
> by machine and it was set wrong. Maybe? I have a friend with a Knabe 
> concert grand with a serial number just 20 from mine so it must have been 
> built about the same time. I looked at his and it was the same way. Is this 
> by design?
>>>>Yes and also the knabe cracking problem is due I think to the orientation 
of there maple grain. Whatever they were doing and thinking it wasn't as 
effective as some other ideas>>>.
  Does it contribute something to the sound quality (or lack of)? I would 
like to do it 
> the correct way.  Any suggestions.   Thanks ,  Gary Teters
> 
> 
Not necessarily
     A good termination has many facets. Proper string to front of bridge 
angle determined by crown , bridge height and the way it was originally cut. 
ie sloping towards rear string rests  a bit. Also this is an old piano and I 
suspect it has suffered at least some loss of crown/bearing. All that to say 
look carefully at all the component pieces of the tone producing items under 
discussion.
........Dale Erwin>>>>>>>>>>>




---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/eb/dd/d6/bb/attachment.htm

---------------------- multipart/alternative attachment--