[CAUT] Getting straight

Fred Sturm fssturm at unm.edu
Thu Aug 7 15:05:26 MDT 2008


Hi Ed,
	I tend to agree with the notion that common stringing techniques  
probably don't create false beats of the sort Jim Ellis was able to  
create, as your conversation with Jim would seem to confirm. In fact,  
it seems likely to me that the scenario he describes would be very  
rare indeed, except in the case of tied tails. It isn't entirely clear  
whether or not there are gradations of one sort or other, as the  
experimental setup describes an untwisted residual curl aligned  
precisely. It does seem that he pretty clearly eliminated twist per se  
as a cause of falseness. I am intrigued by the possibility that a bit  
of twist might counteract the establishment of beat patterns, as the  
arch created by the curl would be distorted, perhaps enough to prevent  
the creation of clear counter-pattern of vibration.
	My purpose in writing at some length is to try to counteract a knee  
jerk reaction, learning from the experiments more than is warranted. I  
think there is a tendency to seize on a factoid and extrapolate a lot  
of additional theories that really aren't supported either by the  
evidence or by the case being made.
	What Jim has established (to his great credit) is a single potential  
cause of "false" beating. Looking at it very carefully, I think it is  
safe to conclude that this is an exceptional, not a common, cause. And  
while it may "make sense" that twisted wire is a "bad thing," the  
evidence he presents suggests no such thing, in fact the contrary if  
anything.
	But by all means, let's all go out and buy string straighteners. We  
always need a new tool <G>.
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu



On Aug 7, 2008, at 1:35 PM, Ed Sutton wrote:

> Fred-
>
> I spoke with Jim about this when he was writing the article.
> As I understood him, he felt that if the hitch pin bend is made in  
> the plane of the coil before attaching tuning pins, the rest will  
> tend to follow in such a way as to avoid false beats. We didn't  
> discuss the "forward" and "backward" tuning pin coils that you  
> mention.
> I have a little pliers that are just right for bending the becket,  
> so I think I succeed in getting the "backward coil" on the tuning  
> pin without twisting the wire.
> Most interesting is to think about single tied strings, and also  
> what happens right next to the plate struts where strings are more  
> likely to be twisted in tight quarters.
> Sadly, Jim is planning to close his lab, and these are probably his  
> last investigations.
>
> Ed Sutton
>
>
> ----- Original Message ----- From: "Fred Sturm" <fssturm at unm.edu>
> To: "College and University Technicians" <caut at ptg.org>
> Cc: "James Ellis" <claviers at nxs.net>
> Sent: Thursday, August 07, 2008 3:09 PM
> Subject: Re: [CAUT] Getting straight
>
>
>> Some further thoughts on stringing and residual curl of wire.
>> The obvious conclusion from reading Ellis' article is that if you  
>> straighten wire, you won't have the type of "false" beating he   
>> describes. Suppose you don't straighten wire, though. He talks  
>> about  the natural tendency when stringing to follow the residual  
>> curl when  making coils on the tuning pin and bending around the  
>> hitch. I  certainly agree this is a normal, "go with the flow"  
>> method of  stringing. However, I think this procedure puts a 180  
>> degree twist in  one side of a two tuning pin system.
>> Take the normal procedure of stringing left to right (bass to   
>> treble). We make the coil for the left tuning pin, following the   
>> residual curl. The wire leaves the pin towards the hitch, with the   
>> residual curl aiming to the left or bass. We pull the wire around  
>> the  hitch. If we follow the residual curl in this bend, it means  
>> we have  to "turn the curl over" creating a twist in the wire. I  
>> think that  this is, in fact, what most stringers do. Now the wire  
>> comes toward  the second tuning pin with its residual curl headed  
>> in the direction  we want to use to make the next coil. So this  
>> second portion of the  wire will have no twist. (Note that  
>> stringing right to left merely  reverses this scenario, with the  
>> twist occurring when the coil is made  on the left pin).
>> Suppose we decide we want to avoid that first twist. We make the  
>> bend around the hitch pin using a round nose pliers. Now the curl  
>> is  heading back to the second pin in the direction opposite to  
>> what is  needed to make the coil on the pin. So we have to "go  
>> against nature"  and try to get a good coil on the second pin in  
>> the direction opposite  the curl of the wire. It can be done, but  
>> it is troublesome. What  would be more natural - following the curl  
>> when making the coil -  would put a 180 degree twist in this part  
>> of the wire.
>> So I am willing to speculate that most stringing is done with   
>> something like a 180 degree twist in half the wire. Is this a  
>> problem?  It doesn't seem to be in my own experience. Maybe others  
>> have  experience that differs. Ellis' experiment suggests that a  
>> wire with  residual curl that is twisted won't create a "false"  
>> beat, at least in  the controlled circumstance he documents, where  
>> one end is rotated 45  degrees one way, the other rotated 45  
>> degrees the opposite way. It  would be interesting and useful to  
>> have a test on the scenario of a  horizontally oriented curl, with  
>> one end rotated 180 degrees from the  other. That would emulate  
>> what we probably do most of the time.
>>
>> This is for two pin stringing. Things change when you have a tail.   
>> The orientation of the curl is probably fairly random coming off a   
>> tail on a hitchpin. This gets me thinking about harpsichords,  
>> which  often have horrible false beats in some strings. Termination  
>> rarely  seems to be the culprit. But it seems like the scenario  
>> Ellis  describes, of residual curl being at an angle away from  
>> vertical or  horizontal, could well be the primary cause. Curl  
>> orientation off the  tail/hitchpin could well be the same as the  
>> orientation from the  tuning pin coil, as there isn't nearly the  
>> tendency to "follow the  curl" when making a harpsichord coil, and  
>> both could be oriented in  the same direction in a random way.
>> Which leads me to wonder if twisting such a wire (one with a   
>> prominent beat) might be a solution, as opposed to replacing the  
>> wire.  Worth an experiment next time the opportunity presents  
>> itself (meaning  having extra time and the tuning isn't that  
>> critical). And I will  certainly pay attention to curl next time I  
>> string a harpsichord, or  replace a string.
>> Maybe Jim Ellis has already done some testing that might clear up   
>> some of these questions, or might be willing to do some additional   
>> tests.
>>
>> Regards,
>> Fred Sturm
>> University of New Mexico
>> fssturm at unm.edu
>>
>>
>>
>> On Aug 6, 2008, at 7:10 PM, Fred Sturm wrote:
>>
>>> Hi Ed,
>>> Jim Arledge and the Bolducs have both seemingly dealt with this  
>>> successfully. I don't know how. I saw a slide or two of the  
>>> Bolduc's wire dispensing rack, with some devise the wire was fed  
>>> through to straighten it, and thought I understood what it was,  
>>> but when I went  to reproduce it, it didn't work. Probably the  
>>> details have to be  just right. I do know that Jim straightens wire.
>>> A lot of interesting stuff in that article. I can't help wondering  
>>> whether, if you have curled wire, and you can't keep the curl   
>>> horizontal or vertical, maybe putting a twist in the wire would  
>>> help  eliminate the possibility of false beats, that maybe a twist  
>>> might counteract/confuse/break up the pattern. It was only the  
>>> case of a  curl being at an angle from horizontal or vertical that  
>>> consistently  produced the falseness, and when there was a half  
>>> twist in the wire  (admittedly a specific half twist in specific  
>>> directions) no false  beat occurred. Makes one wonder about a  
>>> number of in between  scenarios (the article only mentions  
>>> specifically a string with the  curl at a 45 degree angle between  
>>> vertical and horizontal, and no  twist, producing beats).
>>> Nice to have the kink(s) in the wire hypothesis tested and   
>>> discarded. Though I think most of us had already discarded it  
>>> based  on our own experiences. It will be interesting to see where  
>>> the next  segment leads. I assume we will get to terminations and  
>>> shorter  strings.
>>> Regards,
>>> Fred Sturm
>>> University of New Mexico
>>> fssturm at unm.edu
>>>
>>>
>>>
>>> On Aug 6, 2008, at 4:24 PM, A440A at aol.com wrote:
>>>
>>>> Greetings,
>>>> Interesting article by Jim Ellis etal in the journal this month   
>>>> inre false
>>>> beats from wire twisting against the curl.   I just finished   
>>>> stringing the
>>>> "blood" piano, taking care to keep the curl consistant, and will  
>>>> be interested
>>>> in seeing if there is any difference.  It was a hassle, in  
>>>> certain areas, to
>>>> keep the curl where I wanted it to be,
>>>> so,  now I want to figure a way to straighten the wire before  
>>>> installing.
>>>> I have used the brakes on the small wire reels to straighten the   
>>>> wire, but
>>>> they don't do a very consistant job, leaving me with thoughts of   
>>>> small ball
>>>> bearing wheels with grooves on them and pulling the wire through  
>>>> as  I use it.
>>>> I don't want to re-invent this thing, so if anybody has already  
>>>> developed a
>>>> workable device and found that it makes a difference, how about   
>>>> posting
>>>> something to the list on how well it works and is it worth the   
>>>> trouble.
>>>> Thanks,
>>>>
>>>> Ed Foote RPT
>>>> http://www.uk-piano.org/edfoote/index.html
>>>> www.uk-piano.org/edfoote/well_tempered_piano.html
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>>>
>



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