[CAUT] Getting straight

[Porritt, David]

I'm sorry to hear that Jim is shutting down his lab as he has certainly
contributed some significant research to our field.  

Has any heard from Dr. Birkett lately?  He was doing a lot of research
with a grant that he had received but I can't recall hearing any
reports.

dp


David M. Porritt, RPT
dporritt at smu.edu


-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ed
Sutton
Sent: Thursday, August 07, 2008 2:36 PM
To: College and University Technicians
Subject: Re: [CAUT] Getting straight

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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>