bass string problem

[Michael Spalding]

David,

Here's what P-Scale says about those numbers:

With copper winding, you would have a tendsion of 370#, well beyond the capability of the .0365 core.  

Diameter over the windings should be in the range of .042 to .050.  At .048, you'd have a tension of 180#.

Core diameter should be .034 or greater, to have sufficient breaking strength.

Obviously, the larger the core, and the smaller the diameter over windings, the smaller your wrap wire.  As Ron O pointed out a couple days ago, it's not easy to wind small diameters.

hope this helps,

Mike

----- Original Message ----- 
From: David Nereson 
To: l-bartlett at sbcglobal.net;Pianotech List
Sent: 9/26/2006 3:57:16 AM 
Subject: RE: bass string problem



-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org]On Behalf Of Leslie Bartlett
Sent: Saturday, September 23, 2006 6:46 AM
To: 'Pianotech List'
Subject: RE: bass string problem



Before you get a new string made, it would be worth having a look at the original design on a scaling spreadsheet. Post up the speaking length, cover diameter and the note number on the piano. We can look at the tension to see if it is getting up near critical levels. Quite a few of us on the list have spreadsheets in which we can drop the numbers to see what is going on.

                Well quite a few.......... of you know some stuff about scaling.  I am really ignorant.   Will a scaling program also provide some information about "how to think" about scales, what and why they are, so that persons with no experience can understand something about the whole thing?   I'd like to know enough not to be stupid, but haven't a clue about how one goes to learning such things. If there are scaling programs which help along that way, I'd sure like to know about them.  thanks. les bartlett


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OK, the core wire diameter is .0365", the overall diameter with aluminum wrap is .070", the speaking length is about 32 1/4", maybe 32 3/8" -- can't tell exactly because it's out of the piano and the bridge pins didn't leave very discernible bends.  It's the right-hand string of a 2-string unison on F#3 (note number 34).  
Thanks in advance for any info.  --David Nereson 
   
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