Yes, annoying, isn't it? String leveling is never finished. It happens because the bend in the wire moves. New wire does not take a clear bend when it is first installed, but because it is so stiff it makes a smooth arc through the agraffe. When we hook the wire up, it sharpens the bend in the wire a little. This bend is nicely placed right where it should be, under the capo or in the agraffe. As soon as you raise the pitch, the bend creeps towards the tuning pin, causing the string to push down in the speaking length. This is why I mentioned that I like to do an overall string hook job before leveling - it starts the process of stabilizing the bends, and if you raise the pitch sharp first hopefully the bends will be close to where they will stay. If you are really artful, you raise the pitch exactly enough so that the piano is in perfectly tune after the string leveling . . . . :-) In reality, one can guesstimate the pitch raise by seating one sample string, measuring how flat it goes, then quick pitch raise the piano that much sharp. I attached a slide from one of my stability classes, with pictures of 4 wires. The first is from an old Steinway, the second is a fresh wire just put in and pulled to pitch for a minute or so, then removed again. The 3rd is a more flexible wire (Roslau Blue) that I did the same thing to. The 4th is another stiff wire that I pulled to pitch, then seated and hooked. The bends you see are the capo bar / counter bearing bends. So if you picture having the sharp bend under the capo, you can see how pulling the string towards the tuning pin will cause the 'kink' to move away from the capo, and the smooth arc will try to return, pushing the wire down. Flattening the pitch substantially will cause the string to go up, as the kink begins to move into the speaking length. Don Mannino _____ From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Jim Busby Sent: Tuesday, December 09, 2008 8:39 AM To: caut at ptg.org Subject: Re: [CAUT] String Level Hi Don, Supporting what you said, I also understand that as you tune and the string goes through the agraffe or over the V-bar, the "level" at the strike point can also change. IOW, make them perfectly level with the bubble level, then adjust pitch on a string. Voila! The strings aren't level anymore. This is due to the string "rocking" slightly and pushing it up or down a ways back at the strike point. I studied this a bit trying to figure out why I had to level strings so often. What changes? This "tilting" of the string from tuning seems to be one culprit that no one, to my knowledge, has addressed. It's easy to see once you're looking for it. What do you think? Regards, Jim Busby BYU -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut_ptg.org/attachments/20081209/d0502b61/attachment-0001.html> -------------- next part -------------- A non-text attachment was scrubbed... Name: Wire Bend Illustration.pdf Type: application/octet-stream Size: 90358 bytes Desc: Wire Bend Illustration.pdf URL: <http://ptg.org/pipermail/caut_ptg.org/attachments/20081209/d0502b61/attachment-0001.obj>
This PTG archive page provided courtesy of Moy Piano Service, LLC