Chris,
I found a direct relationship between the "pitch" of the shank made
by plunking it on a hard surface and the sound made by scratching the
shank lengthwise with a finger, fingernail, or other shank. I
believe you mentioned this in a previous post. It made sorting much
much faster for me. 20 minutes tops for the entire set. Thanks for
the insight.
Tim Coates
On May 15, 2008, at 10:22 AM, Chris Solliday wrote:
> I have done a very unscientific survey with my last three hammer
> installs and have concluded that there is a general correlation
> between weight, density and pitch. So now I am doing (1) sort by
> weight, (2) channel, (3) sort by weight, (4) install on rail and
> check pitch, (5) rearrange or remove as necessary. I find not much
> to do (5).
> I find that the difference in weight and in ptich is miniscule .1
> or .2, so moving them around to suit the pitch is not affecting the
> overall strikeweight enough to care about touch wise but COULD be
> affecting the overall tone somewhat and I have no real data here,
> other than a hunch that Tim is right and it feels right. I can hear
> a difference when I don't sort shanks at all, so that tells me the
> process is valid not just for reducing the amount of work to get a
> smooth strikeweight but also MAY contribute to smoothing the tone
> as well. The wild cards are as Ric B describes, real honkers that
> have no real pitch and these should be removed. Lord help you if
> you find more than two in a set. Wake up manufacturers!!
> As David and Jon Page have noted unless you are measuring shank
> radius weight and zeroing out the flange we really can't compare
> results.
> Hope this adds to the mix.
> Chris Solliday rpt
> ----- Original Message -----
> From: Albert Picknell
> To: College and University Technicians
> Sent: Thursday, May 15, 2008 12:19 AM
> Subject: Re: [CAUT] strikeweight
>
> Tim
>
> I agree that there can be a wide variance in shank pitch, and that
> it amounts to more than a few shanks that go "plock". I should
> probably clarify that when I sort shanks, I find that there is not
> only a range of pitches, but a whole spectrum of tonal qualities as
> well, from the plinkiest plink to the plockiest plock. Often there
> will be two shanks with almost identical pitches, but one rings out
> clearly while the other requires much closer concentration to
> identify its pitch. In this case, I did not weed out the plockers.
>
> I too am sort of sitting in the middle on the sorting by weight
> discussion, but with more research we may eventually get a little
> closer to an ideal (not that there will ever be anything resembling
> universal agreement on what that ideal is!). Perhaps the
> "strikeweight" people are sacrificing something in terms of
> voicing, while the "shank pitch" people are sacrificing something
> in terms of evenness of touch; both have valid reasons for choosing
> to give one characteristic precedence over the other. Perhaps one
> "ideal" would be to buy ninety sets of shanks and sort them all by
> pitch and by radius weight :>) Unfortunately, my R&D budget
> doesn't permit me the luxury of trying it out :>(
>
> Pleased to be taking part in this respectful discussion,
> Albert
>
>
> Tim Coates <tcoates1 at sio.midco.net> wrote:
> Albert,
>
> It would be nice to see a study that correlates strike weight to
> pitch. I sorted the last set of shanks I installed first by strike
> weight and then checked to see if they were in pitch order. They
> weren't. I tried clipping off some excess shank to find a pitch
> change, I really couldn't. This particular set only had a variance
> of .2 of a gram throughout the entire set. I reordered them by
> pitch and installed them in that order. I will continue to sort by
> pitch because it makes my voicing much easier.
>
> I respectfully disagree that shank pitch is insignificant. I use
> the word "respectfully" purposely. I know the "strikeweight"
> people have their reasons for insisting on using their methods to
> sort, but I know of others more learned than me who feel that type
> of sorting is inconsequential. I am sitting in the middle about
> the sorting by weight discussion.
>
> I find there is a very, very wide variance in shank pitch and it
> amounts to more than just a few shanks that go "plock". It ends up
> being a wide variance with a very even progression of pitch.
>
> I'm not trying to argue here just present experiences that I have
> and share them. I have not responded to much of the discussion
> since I first brought up the shank pitch. I have not been swayed
> by the information presented to change my ways. It isn't worth
> arguing about and I want to make sure no one thinks I am trying say
> my method is the correct method. I am just saying it is
> comfortable for me.
>
> Tim Coates
>
> On May 14, 2008, at 7:43 PM, Albert Picknell wrote:
>
>> Thank you, Ed
>>
>> Your first sentence states directly what I was hinting at in my
>> last point, namely that since it would be very difficult to
>> predict what resonating qualities a shank/hammer assembly will
>> have once the shank ends are trimmed off, it may be rather
>> pointless to try to use shank pitch as a primary sorting
>> criterion. And your second sentence reminds me of what Ted
>> Sambell taught us many years ago (I was one of his students back
>> in the '80's): always listen to the tone of the shanks before
>> installing them. The ones that go "plink" can go in the piano;
>> the ones that go "plock" can go somewhere else. There is no
>> sorting by pitch, just a test that weeds out the shanks that are
>> more likely either to break due to irregularities in the grain, or
>> to adversely affect the tone by flexing too much, damping tone, etc.
>>
>> Thank you, David, for your comments too. It sounds like there is
>> more to be gained by sorting shanks according to what effect they
>> will have on the touch rather than what pitch they produce before
>> being coupled with hammers and mounted on rails. As long as they
>> are good and stiff (they go "plink" rather than "plock") they
>> should do the job.
>>
>> Am I reading you correctly?
>>
>> Albert
>>
>>
>> Ed Sutton <ed440 at mindspring.com> wrote:
>> David-
>>
>> Once the hammers are hung, the "pitch" of the shank/hammer will be
>> altered, so I don't see how the "shank tone" as such is significant.
>> However, when all other factors are the same, it may be an
>> indicator of the stiffness of the wood, which may influence the
>> response of the action.
>> For example, my sense in a short trial of Bruce Clark's action
>> with carbon fiber shanks was that it was fast and even in response
>> and delivered easy power for the effort. But that was a short
>> trial by a low-skilled performer, and there are many other
>> creative adaptations in his design that make it work so well.
>> Nevertheless, those carbon fiber tubes should be able to deliver a
>> very perfect and even "plinck" line. not to mention even weight
>> and stiffness.
>>
>> Ed Sutton
>> ----- Original Message -----
>> From: David C. Stanwood
>> To: College and University Technicians
>> Sent: Wednesday, May 14, 2008 6:03 PM
>> Subject: Re: [CAUT] strikeweight
>>
>> Dear Albert,
>>
>> Great work and very interesting and important ideas you are
>> working with! My comment: Most of the dead weight is concentrated
>> in the flange and flange/knuckle end of the shank and I would
>> imagine that for that reason the dead weight value might relate so
>> much to it's effect on tone...
>>
>> I would be very interested to see additional data using Shank
>> Strike Weight (SS) instead of the dead weight of the Flange/Shank
>> assembly. This value measures the weight of the shank tipped on
>> a roller bearing with the flange oriented vertically so that it's
>> weight is not measured. The end of the shank rests on the scale.
>> Values are usually aroun 1.4g for narrow shanks and 1.8g for
>> regular shanks. We routinely sort shanks, within each type, by
>> weight, then hang the hammers, then measure Strikeweights, then
>> add or subtract hammer weight to smooth the strikeweights to a
>> curve of our choosing.
>>
>> The "thinking" is as follows: Shank Strike Weights can very
>> within a shank type within a set by as much as 0.6g. These
>> variations don't show up in the StrikeWeight measure but when we
>> measure the Strikeweight and make changes in hammer weight to
>> smooth the curve we may be changing hammer weight to compensate
>> for a variation in SS. .6g of SS will not have the same inertial
>> moment as .6g of hammer weight because the center of weight is
>> different. (a physicist could explaing this more eloquantly than
>> me). So by sorting the SS by weight we theoretically make the
>> inertial moments of the shank/hammer more even as related to
>> smooth Strike Weights.
>>
>> Here is a drawing of the setup:
>>
>> http://www.stanwoodpiano.com/ss.jpg
>>
>> Hope this helps.
>>
>> David Stanwood
>>
>>
>>> Hello List
>>>
>>> Chris Solliday <csolliday at rcn.com> wrote ('way back on Feb 20):
>>> Alot of good ideas and ways for producing some very refined work
>>> are being floated regarding shank radius weight and hammerweight
>>> which combine to produce strikeweight and the action's main
>>> contribution to overall tone. ...
>>> ...I pre-sort the shanks heavy to light bass to treble before I
>>> channel them and then again after channeling them. I too find
>>> that this reduces the quantity of the variation if not the
>>> relative variation. I do not make a spreadsheet until that point
>>> after the second sorting. ...
>>> ...I may be going over the shanks twice but I have much less work
>>> in the end.
>>> I am intrigued at the possibility of working shank tone into the
>>> equation and will be first looking for a correlation between
>>> pitch and weight.
>>> Thanks,
>>> Chris Solliday
>>>
>>> This is my first posting to this list, so I hope at least some of
>>> you find what I have to say interesting and/or useful. Back
>>> around mid-February a series of threads ran on this list entitled
>>> "Shank to Hammer weight spreadsheet", "strikeweight", and "Shank
>>> Pitch". The comments at the very end of Chris Solliday's post
>>> (see above) particularly caught my attention, so I thought I'd do
>>> a little "tinking" and weighing to generate some data which Chris
>>> (or anyone else) might find useful.
>>>
>>> My data-gathering proceeded as follows:
>>>
>>> Taking a box of new Renner shanks with flanges for Steinway, I
>>> first separated the "regular" from the "thinned" shanks; the set
>>> contained 59 and 31 shanks respectively. Then I listened to the
>>> pitch of the shanks and arranged them in order from lowest to
>>> highest. Interestingly, both groups of shanks fell into the same
>>> overall pitch range, i.e. the major third A#5 to D6. The thinned
>>> shanks covered a slightly narrower range, but that is probably
>>> due to the fact that there were fewer of them.
>>>
>>> Next, I weighed each shank/flange assembly and recorded its
>>> weight, to the nearest tenth of a gram. This was just the dead
>>> weight of each assembly on the scale.
>>>
>>> Next, using a Correx gauge, I measured centre pin friction, also
>>> to the nearest tenth of a gram. This involved some estimating
>>> and averaging, but I used a consistent technique, so I think the
>>> numbers are pretty good.
>>>
>>> I entered these data into an Excel file, and generated charts
>>> from them in order to visually illustrate whatever correlations
>>> might exist. The file is attached, including charts - have a
>>> look. The data series with the connected blue dots represent the
>>> regular shanks; the unconnected pink dots represent the thinned
>>> shanks. The lowest- and highest-pitched thinned shanks are
>>> numbered to correspond with the regular shanks which had the most
>>> closely matching pitches; the rest of the thinned shanks are
>>> distributed as evenly as possible between those two extremes.
>>> Distributing them this way enabled me to plot them all on the
>>> same graphs in a somewhat meaningful way.
>>>
>>> Finally, to further explore the relationships of shank thickness
>>> and shank length to shank pitch, I altered three regular shanks
>>> as follows. The first one, which had an initial weight of 7.0 g
>>> (including flange), I thinned substantially, removing 0.5 g of
>>> material. The pitch of this shank dropped by about a minor 2nd.
>>> The second one, which had an initial weight of 6.9 g (including
>>> flange), I shortened by approximately 24-25 mm, equivalent to 0.4
>>> g of material; the pitch of this shank rose by about a perfect
>>> 4th. The third one, which had an initial weight of 8.5 g (it had
>>> a larger flange attached), I first thinned by 0.5 g, which
>>> lowered the pitch by a little less than a major 2nd. Then I cut
>>> off shorter segments of approximately 7 mm each (each weighing a
>>> little under 0.2 g); each of these cuts raised the pitch about a
>>> major 2nd; the cumulative effect of these three cuts was a pitch
>>> rise of about a tritone. Altogether, this last shank ended up
>>> thinner, shorter, and about a major third higher in pitch than
>>> where it was at the beginning.
>>>
>>> Some observations/conclusions:
>>>
>>> 1. As I mentioned above, both the regular and thinned shanks fell
>>> into the same overall pitch range, i.e. the major third A#5 to
>>> D6. Hence, if one is going to sort shanks strictly on the basis
>>> of pitch, the regular and thinned shanks will end up being
>>> interspersed.
>>>
>>> 2. There is a significant amount of overlap in the weight ranges
>>> of the regular and thinned shanks. So if one is going to sort
>>> shanks strictly on the basis of dead weight, again the regular
>>> and thinned shanks will end up being interspersed.
>>>
>>> 3. The trendlines in the "Pitch vs. Weight" chart seem to
>>> indicate that, as a general rule, heavier shanks have a higher
>>> pitch. For two reasons, I suspect that the variations in pitch
>>> are primarily a result of differences in wood density from shank
>>> to shank. First, because the substantial thinning I did on two
>>> of the shanks I altered resulted in pitch changes of less than a
>>> major 2nd, I doubt that the slight dimensional variations which
>>> may exist after Renner's precise manufacturing process are likely
>>> to result in pitch differences amounting to a major 3rd. Second,
>>> the fact that the regular and thinned shanks produce pitches that
>>> fall within the same range suggests that something other than
>>> dimensional variations are responsible for the pitch variations.
>>> Another obviously potential source of variation in the weighing
>>> process is differences in the weights of the flanges. But I
>>> suspect that if one took the trouble to weigh the flanges
>>> separately, although there would be some variation, the data
>>> would generate a flat trendline. Anyone wishing to test this
>>> hypothesis is welcome to do so; right now I don't have time.
>>>
>>> 4. The random distribution of tighter and looser flanges
>>> throughout the entire range of pitches, and the flat trendlines
>>> in the "Pitch vs. Friction" chart seem to indicate that the pitch
>>> of the shanks is not affected by the pinning (although I do
>>> believe the pinning does affect the tone in the piano). To test
>>> this conclusion a little further, I took a relatively tight
>>> assembly, treated it with CLP to reduce the centre pin friction,
>>> and listened to the pitch again; there was no change in pitch.
>>>
>>> 5. Removing material from the end of a shank has a significantly
>>> greater effect on the shank's pitch than does removing an
>>> equivalent amount from the sides. Whether this is something that
>>> needs to be taken into account when sorting shanks may be worth
>>> considering, because when the shank ends are trimmed after the
>>> hammers are installed, they aren't all necessarily shortened by
>>> the same amount.
>>>
>>> The really tough question now is, what am I going to do with
>>> these things?
>>>
>>> Albert (Bert) Picknell
>>> Head Piano Technician
>> The Banff Centre
>>
>>
>>
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