Thanks, Alan and Jim for pointing this out. I think we are getting confused with figures. Or with the radius when we mean the curvature. Of course, the radius is one half of the diameter. I think I was careful to say the radius produced by a rod of 2.5mm dia. If not, I apologize. But have we looked at a 1mm diameter profile? It may well be that this might be a desirable termination, but has anybody ever seen this in a piano? I certainly have not, in a career spanning 69 years, and having re-strung over 200 pianos. 1mm. dia. is exactly the same as a #60 twist drill, barely more than one half of the diameter of a #6 bridge pin, and identical to gauge 17.5 Roslau wire. From a manufacturing point of view point of view I believe the gains would be minimal, if at all, and the difficulties considerable. I agree with Ric that the removable capo bar is a good idea, as were many other 19th. century features. I also think that many were abandoned before they reached their potential. With modern production methods and materials it might be worthwhile to take another look Piano design is in somewhat of a rut in my opinion, and the work being done does not amount to much more than tinkering with what we have. Now, as for buzzing strings, one of the most difficult experiences I ever had was at an important concert I tuned for many years ago at the Stratford (Ontario) Festival. The piano was a rented C and A Steinway D, and was chosen by the artist's agent three weeks beforehand. It had about twenty buzzing strings in the tenor, one or two per unison. With forty-five minutes to tune, which was often the case there, desparate measures were called for. What I did was to pry each buzzing string up with a screwdriver and saw the pitch up and down to wear the agraffe hole smooth. Fortunately it worked, but was not an experience I care to repeat. Regards to all, Ted Sambell---- Original Message ----- From: "Alan McCoy" <amccoy at mail.ewu.edu> To: <caut at ptg.org> Sent: Monday, April 23, 2007 8:47 PM Subject: Re: [CAUT] Hardness of termination vs string breakage (was Re: restrung D) > Hi Ted, > > Pardon my thick-headedness. If a #40 drill has a .097" diameter, wouldn't > that mean that it has a radius of .0485". If you like a capo with a radius > of (2.5mm or ) .098", wouldn't a #9 drill that has a diameter of .195" > (r=.0975"), then be a better visual reference for a radius of .098"? > > Am I missing something, or when is a radius not a radius? > > Alan > > >> From: Ted Sambell <edward.sambell at sympatico.ca> >> Reply-To: "College and University Technicians <caut at ptg.org>" >> <caut at ptg.org> >> Date: Mon, 23 Apr 2007 14:21:19 -0400 >> To: "College and University Technicians <caut at ptg.org>" <caut at ptg.org> >> Subject: Re: [CAUT] Hardness of termination vs string breakage (was Re: >> restrung D) >> >> >> Alan, you are close enough. 2.5mm converts to .098" Agraffes are >> generally >> close to this too. A #40 twist drill has a diameter of .097, which will >> give >> a good visual idea of the radius. One thousanth of an inch or so is >> certainly a permissible tolerence >> >> Ted Sambell >> >> >> ----- Original Message ----- >> From: "Alan McCoy" <amccoy at mail.ewu.edu> >> To: <caut at ptg.org> >> Sent: Monday, April 23, 2007 12:41 PM >> Subject: Re: [CAUT] Hardness of termination vs string breakage (was Re: >> restrung D) >> >> >>> Ric, >>> >>> Would you mind quantifying "thin" and "sharp" for me? Ted Sambell talked >>> about a 2.5mm radius, which works out to 0.1" or between a sixteenth and >>> an >>> eighth inch radius (for metric-phobes). >>> >>> Thanks. >>> >>> Alan >>> >>> >>> -- Alan McCoy, RPT >>> Eastern Washington University >>> amccoy at mail.ewu.edu >>> 509-359-4627 >>> >>> >>>> From: RicB <ricb at pianostemmer.no> >>>> Reply-To: "College and University Technicians <caut at ptg.org>" >>>> <caut at ptg.org> >>>> Date: Fri, 20 Apr 2007 23:46:46 +0100 >>>> To: <caut at ptg.org> >>>> Subject: [CAUT] Hardness of termination vs string breakage (was Re: >>>> restrung >>>> D) >>>> >>>> String breakage at the capo is more complicated then just one bit. I >>>> have a 9 foot Petrof under my care with the same feature (actually a >>>> pretty good one in my book as well...) The <<soft>> capo sharpened >>>> will >>>> indeed groove over time... but if other issues such as speaking length >>>> of the string and counterbearing angle are compatible with the soft, >>>> sharp capo... then whatever trouble you have with string breakage must >>>> find its roots elsewhere. I havent seen a broken string on this Petrof >>>> (strangely enough) for over 18 months except in the bass and agraffe >>>> sections... and its played hard 6 days a week 10 months of the year. >>>> Three quarter medium strike weights for what thats worth. >>>> >>>> Each instrument is different to be sure, but by and large most whose >>>> experiences I have listened to through the years have reported fairly >>>> consisitently that thin, sharp, and soft works much better over time >>>> then wide round and soft. >>>> >>>> Again... I suggest reading McMorrow for some interesting perspectives >>>> on >>>> exactly this subject matter. I agree tho... the proof is in the >>>> pudding. I've been handling capos as mentioned in earlier posts for >>>> well 25 years now... and have had ample opportunity and more to watch >>>> the results over time. Petrofs and Bosies are not, definitely not >>>> proverbial high treble string breakers. God knows Petrofs have >>>> problems >>>> they need working out... but this is not one of them. Not in my >>>> experience anyways. >>>> >>>> Cheers >>>> RicB >>>> >>>> >>>> With all due respect. I had an experience several years ago with a >>>> Bosendorfer grand which seems to contradict this. It continually >>>> broke >>>> strings in the top section. Bosendorfer, and I believe Petrof have >>>> retained >>>> a feature found in early 19th. century pianos such as Streicher and >>>> Erard, >>>> namely, a removable treble capo bar. I removed this and found it to >>>> have a >>>> very sharp edge, and to be badly grooved, the edges of the grooves >>>> still as >>>> sharp as the unworn arears. The metal was quite soft , so I was >>>> able >>>> to >>>> easily reshape it to the radius resembling that of a 2.5mm rod, and >>>> polish >>>> it. I then re-strung the section (actually the two top sections) >>>> and there >>>> has never been a broken string since over many years. The piano is >>>> used >>>> quite heavily by good pianists. Moreover, if anything, the tone was >>>> better >>>> than before. A vibrating string is quite evidently being stretched >>>> at >>>> amplitude . and the consequent lengthening is offset by the >>>> alternating >>>> termination point caused by the deflection of the wire around the >>>> radius of >>>> the bar. As is said, the proof of the pudding is in the eating. >>>> >>>> Ted Sambell---- Original Message ----- >>>> From: "RicB" <ricb at pianostemmer.no> >>>> To: <caut at ptg.org> >>>> Sent: Thursday, April 19, 2007 3:00 AM >>>> Subject: [CAUT] Hardness of termination vs string breakage (was Re: >>>> restrung >>>> D) >>>> >>>> >>>>> >>>>> It is a matter of all these things, including hardness. Really, >>>> this kind >>>>> of goes without saying. A soft sharp profile will wear and >>>> groove, and it >>>>> will do so in a way that works out nicely over time. A rounded soft >>>>> profile on the other hand will buzz like crazy with wear. Dig out >>>>> McMorrows book for some good perspectives on it. >>>>> >>>>> Fred, there is friction at the bridge pin from something... this is >>>>> obvious because of the pins getting damaged over time. If the >>>> metal of the >>>>> pin was significantly harder then the string... these same >>>> moments would >>>>> still be at work and the wear and tear would be transfered to the >>>> string >>>>> material. >>>>> I mean... why would we have any use for super hard abrasives like >>>> diamond >>>>> files or any such thing unless the basic idea that harder vs softer >>>>> results in softer loosing ? >>>>> >>>>> Cheers >>>>> RicB >>>> -- >>>> >>
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