[pianotech] Rubbing hammers

[David Love]

During the hanging of the hammers they were not rotated enough clockwise.  You will need to either heat the shanks and rotate them (easier) or rehang them (harder).  However, when you do that the tails will rub, or the left side of the tail of the hammer moving forward will rub against its neighbor to the left.  Often bass hammers are tapered on one side of the tail (on the bass or left side) to prevent this from happening.  These weren't.  First you need to see whether the hammers are striking the strings in the center of the hammer.  If they are striking on the right side of the hammer or if the flanges are rotated to the right in order to get them to strike the strings on center, then you will need to rotate the hammers clockwise either by burning in or rehanging.  If the hammers are then striking the strings too much on the left side of the hammer you will have to respace or change the y axis of the flange slightly.  If that causes the left side of the tail to rub on the hammer to its left as it rotates forward then you will need to trim the tail of the hammer on just the one side.  The easiest way to do that is to clamp a smoothing plane (low angle) upside down into a bench vise and remove each hammer in the section and plane off a bit of the tail by hand.  Aren't tools wonderful.  Or, in view of our recent discussion on doing things without modern tools you can chew the left side off with your teeth.  

At least that's my take on it but given the late hour and the adult beverages consumed you should explore the possibility further before you take my word for it.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of limhseng at gmail.com
Sent: Friday, January 28, 2011 8:45 PM
To: pianotech at ptg.org
Subject: [pianotech] Rubbing hammers

Hi,
This is a beautiful C. Walter upright . My questions are-1.how did it happen?. 2. Is there a correct way of respacing the hammers other than filing the sides of the offending hammers? 
Thanks!

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