At 8:24 PM -0800 1/29/02, David Love wrote: >No, it's not the bridge. I've spent a good deal of time >reconstituting it (as it were), repinned, renotched, bearing reset, >secured, etc.. Without twisting the strings, they sound totally >dead, when the strings are twisted they do come up and have quite a >decent sound. Other strings I've used don't require it and sound >good straight on. A bit of a mystery to me. David, I reprint below a message I wrote to the list four months ago. I think the simple answer to your mystery is that stringmaker X is pulling hard enough on the copper and stringmaker Y is not. Last week I got a call out of the blue from a guy in Scotland who set up as a stringmaker four years ago and was having a problem with dull-sounding thick single-covered strings. Apparently the strings are not buzzing but people just say they're lifeless. I asked him to describe his technique and from this description I knew that he could not possibly be applying the proper tension to the copper, which is really very high for the thick gauges. I told him how to change his practice and maybe he will -- if not, he will never make good bass strings. At 1:51 PM -0800 1/29/02, Carl Meyer wrote: >Arledge says "no twist" I think that is because he twists the core >wire before winding. He uses a motor on each end of the core wire >that can be programmed to do whatever. A servo controlled tension >feeds the copper wire. I mention pre-twisting as a possibility in the last paragraph of the message below. One thing I did not mention is the desirability of straightening the steel wire, whether for bass strings or plain wire. A set of bass strings should hang almost vertically. JD _________________________ Message-Id: <5.1.0.14.0.20010902133006.00ac5c30@pop3.demon.co.uk> Date: Sun, 02 Sep 2001 15:31:07 +0100 To: pianotech@ptg.org From: John Delacour <JD@Pianomaker.co.uk> Subject: Re: Twist GC bass strings? At 15:29 01/09/01 -0700, Diane Hofstetter wrote: >I'm just about to install my first set of Danny's strings in years. > >I forget, my "oldzeimers" is acting up again, I don't need to twist them, >right? I write as a restorer of 27 years standing and as a commercial bass string maker. My answer is that you should twist them and I'll give two reasons: 1. When the stringmaker stretches the steel core on the machine between the chuck and the hook, the wire is "flat", that is to say not twisted. It would be possible to pre-twist the wire and there may even be some masochistic stringmaker somewhere in the world who does so, but I'll deal with this question in a moment. The stringmaker next proceeds to wind on the copper covering wire. The thicker the covering wire, the harder he has to pull the copper as it is going on, in order that the wire may wrap itself tightly round the steel core. This tension is applied firmly and evenly until the end of the second flattened portion of the core is reached, at which point the wire is broken off. The tension applied to the copper is, of course, less than the elastic limit of the copper wire; the wire is therefore elastic and stretched, having the potential to restore itself to its natural length. At the point where the copper encounters the perimeter of the steel core it is suddenly forced to change direction and the effect of this is to compress the under part of the wire and stretch the upper part _beyond_ its elastic limit. The wire, which was soft and pliable through the stringmaker's gloved hands is now more brittle; its cross-section is no longer round but rather egg-shaped with one side of the egg slightly flattened against the steel. The lesser diameter of this egg is say 8% less than the original diameter of the soft round wire. But in spite of the trauma the copper spiral has undergone, it retains some on the tension that was applied and is trying to unwind. This it cannot do because it is gripped at each end of the steel by the flattened lengths of the steel and the ends of the steel are gripped in the chuck and the hook of the machine. What happens when the string is released from the chuck is that the residual tension in the copper, now free to exert itself, twists the steel core until the opposing action of the steel balances this force. This twisting (ie. unwinding of the copper) is clearly observable by the stringmaker. The actual degree of twist will vary according to the relative thickness of the copper and steel wire; the thinner the core, the less it will resist the twisting force of the copper. Now this release of tension in the copper needs to be restored. A properly made string will not buzz even if the technician installs it without twisting, but nevertheless the copper will not be as tight as it should be, not as tight as it was wound by the experienced stringmaker, and AT LEAST that twisting that occurs on releasing the string from the machine should be restored to it. 2. To be sure of regaining the lost tension, at least one whole turn would need to be applied, but experience shows that the tone of a (new) string will actually be improved by further twisting. I personally give at least two full turns to the thinnest strings and at least one full turn to the thickest. The great makers (of the past) vary in their practice but many of them did roughly the same and after 120 years their strings still sound good. I don't believe this increased brilliance of tone can be explained simply by the fact that the twisting tightens the winding, though this is obviously a factor. There are many contributory factors to piano string tone and the most obscure of these is at the molecular level, for which there is no exact science. When a replacement bass string is first installed, it will rarely sound as good as its neighbours, provided these are in good order, and the difference can sometimes be so great as to lead one to suspect the quality of the new string. After two or three days and one or two tunings, the difference will be scarcely perceptible. After eight days the new string will either match its neighbours perfectly or exceed them in tone quality. Any experienced tuner will recognize his phenomenon. The cause of it lies in the very gradual realignment of the molecules in the steel and copper wire to accommodate to their new stretched state, that same realignment that leads to the lowering in pitch of newly-installed strings. Finally, I said I would say a word about the possibility of "pre-twisting" the cores before winding. Certainly this would do no harm, but from the stringmaker's point of view it is not only a waste of time but rather pointless, since the technician who buys the strings will either know what he is doing or not and no amount of molly-coddling is going to improve the work of a ham-fisted technician. I have one customer with a shop locally. Whenever I visit the shop, I like to hear the strings we have made and judge the results in different pianos. On every set he installs there will be dark marks where the copper has been handled. Every time, I repeat my injunction to him and his son NEVER to touch the copper and either learn to string without touching it or else wear gloves. He will not learn because he belongs to that superior cat-like breed of technicians whose hands never sweat even in the summer! JD
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