[CAUT] Getting straight

[Fred Sturm]

	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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>