Hello Don,
Some comments interposed:
Don Mannino wrote:
snip.....
>
> I am surprised that you are not aware of the pinblock fitting in Kawai
> pianos (also used by other well known brands). These pianos are made
> with rock maple pin bushings, with the bushings actually being plugs
> in the plate holes which are drilled at the same time as the
> pinblock. The tuning pins therefore pivot on the plate webbing, and
> exert a backwards force on the pinblock - towards the pianist, away
> from the plate flange. When this design is used, there is no reason
> to fit the pinblock, as long as the bushings are hard enough wood.
I disagree with this and I am well aware of the fitting used in this
method. Having been through the supposed adequacy of this method
twenty or so years ago with the factory reps on the West Coast while,
at the same time trying to accomdate an unhappy customer who had bought
an unstable Kawai piano with the block installed as you describe which
had been sold by a Kawai dealer I worked with at the time, as I say, I
disagree that this method is equal in efficacy to a properly fitted
pinblock.
I doubt few technicians working with dealers selling pianos using
this method will not have encountered what has been my experience: A
higher rate of instability and a significantly larger number of
customers - who know nothing of the supposed virtues of any of these
methods,- but complain nevetheless because they have a frustrating
experience with the sound and a sneaking suspicion their piano should
stay in tune better. They flat out say it just doesn't stay in tune
well. I have encountered this many times. These problems are, by no
means, simply a function of the tuner's skill or frequency of tuning as
the factory reps, at least to me, one time claimed.
Since then I have, on at least fifteen or twenty pianos, let the
tension down, tightened the plate bolts if loose, filled the voids,
usually with brass shim stock, but on one occasion with maple wedges,
put the system back under tension and had the customer, previously
complaining, now note the piano stayed in tune much better and make
copious commentary to this point.
The KG -2 is, in my experience particularly bad in this respect,
although I have corrected the fit on Kawais, Yamahas, Hyundai, and some
others, perhaps Young Chang, if memory serves.
The proof is in the pudding and, after having seen the difference
in performance, simply as a result of insuring an adequate pinblock fit,
and, also, hearing comments of technicians who have referred pianos to
me for just such problems, I am firmly convinced the one method used by
these Asian companies is a mistake and inadequate entirely.
When one properly fits a pinblock, as I am sure you know, little
can subsequently go wrong if the fitting has been done adequately using
a well made block, nor is this difficult to achieve. Yet, by your own
commentary, you indicate that something so important and central to the
instrument, tuning stability, is allowed to be dependent upon something
so ephemeral as the quality of the wood in the bushing. This seems
entirely a manifestation of poor judgement to me. Furthermore, it is
not dependent merely on the quality of the wood of the bushing but also
upon the type, number and placement of pinblock screws, the
characteristics of the alloy used in the metal of both screws and tuning
pins, the ability of the plate to stay fixed to the rim, and, no doubt,
other factors. Also, it renders the entire system much more sensitive,
in my opinion, to moisture fluctuations.
Admittedly, as you are lucky enough to have had an experience of,
some of their pianos will retain an acceptable level of stability,
although I would say it takes an exceptional tuner to produce a really
great level of stability on such pianos. In my opinion, while one
owner may indeed have a piano capable of a reasonable level of
stability, other owners may not be so lucky, and another instrument may
be seriously deficient in this regard. Further, on most of these
pianos, those of Kawai, Yamaha, and of several companies, the block
usually contacts the flange to some degree or another, which I think,
complicates matters substantially and markedly increases the possiblity
of problems.
Where this happens, I have actually tracked changes in the
fitting over time as the block, apparently, moves, as you say, by
pivoting on the bushings or expands and contracts with the moisture
content and thus changes the contacting areas. Obviously, an intricate
interaction must occur between the moving or expanding of the block, the
tension in the strings and the amount of compression in the bushings,
wedged as they are, between the side of the hole and the tuning pin.
How this aspect of the method could be said to be advisable, or, even,
merely acceptable, as regards stability, is a mystery to me.
Plainly, such a method, that is relying upon the load being
transmitted to the plate by the bushing, and, at the same time,
allowing the block to fit the flange through a portion of its length,
must demonstrate the drawbacks of either approach and be especially
sensitive to moisture cycling, loose plate bolts and pinblock screws, in
particular, possibly, thermal expansion, the dreaded compression set so
feared here, and possibly, even more readily expose poor or merely
adequate hammer technique on the part of the tuner. I think such a
method should not be accepted - why rely on a system that can, and, in
my opinion, does, go wrong in so many ways when the readily available
alternative lacks these vulnerabilities. Most of the pianos that I have
repaired, possibly all, have been in this category. Yet, most of the
pianos one sees using this method have just such a combination of
effects, which is ill-advised, in my opinion.
I, too, have never seen a Kawai with the kind of failed pinblock
referred to in the earlier post and was surprised to see such
commentary, as I believe their blocks themselves are quite adequate.
Yet, a negative impression exists, among some technicians as regard this
company and I think the instability of their blocks, to whatever degree
it does exist, which as I say may be variable, is partly responsible for
this impression.
The use of this approach suggests to me that the engineers have not
properly considered feedback from the field. They certainly have had it
from me in times past. Perhaps they come from the same school of
thought that designed the Japanese carriers at Midway.
> Many technicians in the US have a very hard time picturing this,
> because we were all brought up in the Steinway style of construction,
> where the pin does not touch the plate (or should not, I guess), so
> the plate is being pulled towards the flange and down. In Kawai
> pianos (as well as Yamaha), the pinblock is being pushed back.
>
> Those who tune a lot of Kawai and Yamaha pianos will tell you that
> they are as stable as any - as long as the bushings were made with
> good wood.
I have tuned a very lot of them and would disagree with this.
> I have heard about 1 piano made in the 70s where the grade of the wood
> in the bushings apparently wasn't hard enough, and the pinblock
> moved. But again - I have only heard of this once, and although there
> are undoubtedly others, condemning the brand because of the method of
> construction reflects a lack of understanding.
>
> I do think that your not realizing why the pinblocks have not been fit
> has made you feel like the company just didn't know any better - which
> is a natural conclusion giving the usual technician training. I am
> guilty of making the same mistake in the past, and when I first talked
> to one of the (very well educated and experienced) Kawai engineers in
> Japan about it, the concept was explained fully. I was duly corrected
> and told him so - but I told him they should still fit the pinblocks
> just to keep the technicians happy :-)
Perhaps they should try it to keep the customers happy. (Sorry this was
a low blow but I couldn't resist it.).
> A few years back Kawai America had a strung plate out of a Kawai grand
> piano with pinblock attached (the piano had been dropped from the back
> of a moving truck, so we were taking it apart). We loosened the plate
> screws, and sure enough the pinblock swung back, away from the flange
> just as the engineer said it would.
I don't know why it would take an engineer to expect this would be
likely to happen. But, one may need an engineer to consider all the
other effects of this motion, the forces that produce it and moment
associated with it. The proper design, should one be committed to such
a system, would be to cast a flange in the plate at the front of the
block and plate, thereby trapping the block and stabilizing its
motion. Obviously, the factory believes it has a system that works and
that this motion is constrained but, as you can see, I must, from
experience, disagree.
This motion, not competely constrained at times, as I believe it
is, although the factory will, no doubt, claim it isn't and that this
has been thoroughly analyzed, which it hasn't, contributes to string
breakage along with tuning instability, particularly around the fourth
octave and upwards as it has, I believe, the effect of forcing upwards
the webbing area of the plate, this being also another source of the
instability sometimes evident. I believe that the combination of this
backwards force and the moment it exerts against the plate, when
combined with loose plate bolts, which, of course, should be prevented
by proper maintainence but so often are not, account, to some degree,
for the frequently found string breakage on such instruments. Usually,
the pianos I have repaired with these problems have exhibited string
breakage which, in general, ceases upon the repair. The hammers are
normally, voiced some too and this may, of course, reduce the subsequent
tendancy to breakage, although, this corrective normally has already
been tried before the repairs described above have been made and found
inadequate. .
>
>
>>
>
> snip
> I don't think that the objections you've received here on the list are
> because you are sharing your experiences about problems with
> particular pianos, but that you are condemning a brand in general
> because of those experiences. You need to realize that all of us tune
> these pianos regularly, and saying that Kawai pinblocks will generally
> go bad in 10 years is telling hundreds of technicians something that
> they know from experiences is not true - our collective experience
> does not support your statement, so some have been kind enough (from
> Kawai's perspective) to say so.
I agree one hundred percent that these blocks do not go bad as
described, but there may well be, as I said above, a level of
frustration encountered by tuners with these instruments, particularly
in certain environments.
>
> Thanks for giving this issue a little re-consideration, Ron. I hope
> that you get the chance to rebuild some more Kawai grands that don't
> give you such a negative impression.
>
> By the way, for those who are wondering, if you do replace the
> pinblock in a Kawai, then I recommend that you go ahead and fit the
> block to the flange, because duplicating the hard bushing / drilling
> procedure used in the factory is not easy. The replacement bushings
> are generally pretty soft, and most rebuilders' shop procedures make
> pinblock-to-flange fitting a standard operation anyway.
>
> A last comment to all posters of this list, if I may. One of the
> problems with any of us posting strong negative comments on this list,
> whether about people or about piano brands, is that these comments are
> very commonly reprinted and mis-used. It is very easy for a competing
> dealer to pull a message like Ron's from the archives, print it out,
> and make photo copies to show all of their customers as to why they
> should never buy a Kawai piano. Once a critical comment is written,
> whether it is accurate of not, whether opinion or fact, it becomes a
> permanently archived nasty tool which can be used against the target
> of the criticism. I am sure that negative posts like Ron's are very
> rarely done with intentional malice in mind - but they are still used
> in very malicious ways, being posted as "a fact from the PTG piano
> technician's list." I have no doubt that Ron's post will be returned
> to us at Kawai many times by Kawai dealers who get a copy from a
> customer, who was given it by a competitor talking down Kawai. It
> happens every time a post like that is written. This is why
> manufacturers cringe at these kinds of public posts - no matter how
> they were intended, they are almost always misused later, and it
> really is quite painful.
Personally, I believe Kawai, in the Shingeru particularly, and the RX
line to a lesser degree, builds a very high quality instrument and has a
commendable forward looking attitude, - the ABS parts, which I think are
progess for the industry, for example, demonstrate this. To my ear, the
Shigeru is the greatest piano ever built in Asia and, truly, an artistic
instrument of the first order. Nevertheless, as I see it, where they
use the method described above to fit their blocks, a better approach
could easily be had, and would, of course, be much more desirable from
my perspective even though I have made some good money repairing such
problems.
Regards, Robin Hufford RPT
>
> Don Mannino RPT
> Kawai America Thought Police :-)
>
>
>
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