At 17:32 -0700 2/3/10, Arlie Rauch wrote: >I've had the same experience on P22s. In recent years when I have >encountered one of those, I back those two suspect strings off a bit >before raising their pitch. I can't prove that is the reason, but I >have not had breakage when using that approach. The reason these strings are breaking is excessive tension in the design, as you will discover if you do the calculations. See: <http://pianomaker.co.uk/technical/string_formulae/> (excuse the layout) Letting the string down a bit before pulling it up is good practice and minimises the risk but it is ultimately just putting off the evil day when the string breaks because it is designed to break. The top strings of the single section and the highest bichords are always the most likely to be over-tight. I recently bought at a discount a new Chinese piano from the distibutor, who had asked me to make three replacements for strings that had broken. I told him if I made them to pattern they would break the next day, took the piano off his hands, replaced nearly all the bass section and sold it cheap in the knowledge that the bass strings will never break now. Somewhere there must be a secret document that tells people how to design bass strings so that they will break. Far too many makers seem to have read it! JD
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