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Is there a place I can find out the differences between pre-1984 Steinway keys/action and post-1984? I believe it affects knuckle and/or capstan placement? Not asking for someone to explain it here, just hoping i might get pointed in the right direction to educate myself (if there is a place). Thanks

The "pre 1984" Hammer flange knuckle was 15.5 to 16 mm from the knuckle center. The "New York Improved" is 17mm. This 1mm to 1.5mm represents a slight reduction in the leverage ratio of the hammer shank assembly.

In the "New York Improved" version of the repetition, the repetition jack pin center was moved by the same amount towards the repetition flange in order to maintain the proper jack angle to the knuckle.

Larry, thank you very much. By any chance, is any of this stuff written up or compiled somewhere where I can look into it in more depth? I guess the type of hammers you use has an effect as well. Is there somewhere i can go to find out all this? Thanks again

This is an interesting subject.

Steinway decreased their leverage ratio by a few decimal points and increased their hammer mass. They are not a company to make fast or hasty changes to anything, being more concerned with keeping their name than risk a failed innovation attempt.

These decisions go against what many very intelligent and thoughtful rebuilders think to be ideal action design, but nevertheless Steinway must have had very good reason to make these changes.

I'm not too interested in history minutiae, but did Steinway begin suggesting a key depth of up to 0.420" around that time? If so, it would make sense. Here's my interpretation and guess as to the motivation of these changes..

Lowering the leverage ratio flattens out its sinusoidal curve, with the peak being reduced by the greatest amount. It seems Steinway was trying to smooth out this high downweight peak at the beginning of the keystroke (which makes actions more volatile/uncontrollable), and then increase hammer mass to keep KE to the string (tone power) relatively constant. Lowering hammer mass outright won't smooth the curve, only knock it down by a few percentage points.. translating rather than reshaping the curve.

So I read into this that they wanted the higher leverage and power from hammer blow at a dip of 0.420", but not the precipitous spike in downweight, so they smoothed the curve a little, in the Viennese style. That creates more of this even, smooth space in the keystroke where pianists have more control to create dynamic range.

Steinway must have determined there was a real demand from artists to do this.

There is, I'll have to dig it up ..

Larry

Same enlarging of the screw to center distance for the German Steinway, I think.

I have found the pdf I received from Steinway some years ago.

I can't post it here at the moment but I can email it to anyone interested.

Let me know.

Larry

I'd like to see it!
Ryan@pianova.net

Also, the Steinway standard key dip block is .400 not .420 as mentioned earlier in the thread. However there is a range of what is acceptable. I think .420 would be on the upper range.

me too, I did send you a PM with my mail

Thanks

I'd really appreciate it too.. thank you..

My e-mail: info@tunewerk.com

The original Steinway action specs produced actions with a comparatively higher leverage than most other pianos. It only works when the hammers are very light. Otherwise the inertia is so high that full dynamic control becomes an almost insurmountable regulation problem.

I prefer the higher leverage, but I go to great pains to adjust the mass of the hammer so as to avoid ruining the feel with gobs of key-leads.

Also the diameter of the knuckle has significant effect on leverage and pianissimo control. When the knuckles are large, the "bump" at escapement felt during soft playing makes smooth and even control almost impossible.

Yup..

I'm waiting for the day they start manufacturing knuckles under 8mm. Why hasn't there been more experimentation around this?

Massively important parameter.

Any idea why the flange screw to center (hammer shank) did enlarge, while at the same time the knuckle you center did.

II seem to appreciate 16mm and 10mm knuckle.lighr hammers but not extra light Then there must be an appreciation of the shank and key compliancy do to avoid having a too stiff part facing a supple one.

I find very supple shanks on a model just before 1930.
This have a large impact on tone with always warm and full basses for instance.

The knuckle friction is used to manage the energy accumulation and release. It gives a sort of guarantee to the pianist by sending back in the key the amount of energy stored while allowing to reduce or to amplify it yet a tiny bit, before the note speaks.

Small knuckle send less pre let off information.

I uploaded the pdf of the repetition drawings to the cloud for easier sharing:

https://drive.google.com/file/d/0B5aGBNgg4B5hUW90TUFxTkg5djA/view?usp=sharing

I'm not sure what you mean by the bolded text. My models show that the ratio is quite constant throughout the key stroke (until letoff, of course), increasing somewhat because of the jack hitting a slightly different part of the knuckle as the hammer rises, and also somewhat depending on the shape of the wippen heel where it contacts the capstan.

Greetings,
I have found a rising and falling ratio during the course of the stroke. On a typical Steinway, the ratio during the first .020" was 5.7, then over the next 040" of key travel, the ratio had risen to 5.9, topping out at 6.2, where it stayed for nearly .080" of dip, then over the next .100". began falling back to 6.0 by the last .030".

I think, ideally, the ratio would either stay the same throughout, or continue to rise from start to let-off, so that full advantage could be taken of momentum by having the highest ratio occur at the point of maximum hammer speed, while having the most favorable ratio to begin things moving.

I nudge actions in this direction by the use of heel height that allows the capstan contact to reach the "magic line" just at the point of let-off. Use of WNG capstans makes friction basically a non-issue.
Regards,

SO, ...

The diagram can be misleading. The obvious, should be the mm difference in the base, between the rep flange pin and the jack flange pin.

I recommend measuring this dimension on your sample parts.

Yes that is also my finding, not as large but better leverage at the begin is easier for playing. Reduced leverage during the stroke as shown (drmonstrated) in the Mario Igrec book sound weird to me and not what I am looking for.

About magic line placement. Do you ever check the one on Yamaha?
I was said they where first to begin to put to line late, but did not verify that with measurements myself.

Usually the magic line refer to mid blow and not half key dip, hence it's venue before half key dip. That can be misleading I think.

All types of setups have been used, optimal leverage at start, mid blow, end of the stroke.

I think we need to keep some acceleration at the begin of the stroke and not a lowering ratio. But I was said pianist seem to appreciate the less perceived stop points (letoff, damper rise)

Magic line attained just before letoff

How do you manage the sharps then? Do you use a smaller here on them?
On some keyboards I measured, I find the sharps sitting on the magic line at rest while the white keys pass them at 0.4mm

Hence less resistance on sharps, not perceived as their levers are shorter.
This could argue for a later passing of the magic line for white keys.

Certainly may depend of location of balance pins, moment where the key stick stick s horizontal during the stroke, that dort of parameters.

I wonder if those are included in the ANSI norm for keyboards (1992,I think).