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Jim, how do rate the adjustment of this Steinway action?

http://www.youtube.com/watch?v=01DBtig_Fgw

There is a close up starting at 0.42.

I am not Jim, but the stack, or/and string height is generally wrong on those action models.

There is way more friction than usually at the capstan level.

shank is a little low at rest,
the jack could be located more front , afterouch is a tad too large...

"Not Jim",
Thank you. The aftertouch should be like image 5 rather than image 6 below?

Jim, All
Would you raise the drop screw a tad and, if so, at which image would you like it to make contact? I realise there is some leeway as Jim and Ed have described.

Image 1.

Image 2.

Image 3.

Image 4.

Image 5.

Image 6.

Ian,

I have trouble answering this, as there is a bandwith of acceptability, which depends on the level of play and frequency of service. Also, I find overall action ratios and hammer density/weight effect where on the bandwidth this action will feel best. Belly response also comes into play. As well, lighter softer hammers appropriately setup have way more leeway in the regulation than hard heavy hammers.

Though I design with a spreadsheet & autocad, once its in the piano, I go tactile, and listen to the sounds.

Having said that, viewed as just jack & knuckle,not knowing what the movement of the jack at the end of the keystroke works out to at the end of the key in this particular setup, it appears that the drop screw could be raised.

How do you like that for a qualitified answer?

Further qualifying this, visually discerning this synchronization is very difficult, because you can't tell visually when each of the felts will be sufficiently compressed to make the two felt contacts felt by the finger.

This is why, for me drop is adjusted by feel, and why though I look at position of the hammer at the end of the stroke, the tactile information I'm weighing happens at the point these pics are illustrating. With the arm and wrist leaning on the keyboard for support, I gently press the key up to the beginning of but not through letoff. This "up to the beginning of but not through letoff" if done slowly, with attention will either show a crisp clear wall of resistance, or a mushy event that feels ambiguous.

I'm looking for the non-ambiguous wall of resistance, as it tells the pianist's finger precicely at what instant to press through letoff. One must be quite attentive to that touch to discern wall of resistance.

At least that's my take. Spreadsheet guys also fly by the seat of their pants...its just the way of it...

Jim Ialeggio

I believe that the red felt compression can be discerned a little on the second pic. Way more with high speed camera indeed. Hopefully we do not need as much speed when regulating than when the piano is really played, but a too slow motion gives a false interpretation of the synchronism... I have told hat yet, nobody agrees, nobody say it is false

So when you look only at the jack you see it raising a bit when the drop screw touches the leather, in absence of the hammer weight and knuckle pressure that is pushing a bit more the jack at a farther position than the one evaluated when positionning it...

This action model could be tested for stack or key "frame" height, key position under the whippen (false) and letoff height. Too much aftertouch / key dip. Definitively wrong geometry.

Ok, a fair point, perhaps. So in your higher velocity scenario, in regulating how would you "prove" that you had them synchronized?

Jim Ialeggio

I agree with you, Jim, that mathematical models get you into the right ball park, then other factors kick in and you have to the best you can.

Isaac, eagle eyed as ever, spotted the compression of the red felt in image 2. By image 3 there's a small gap between the felt and the spoon as the jack goes into let off.

Quoting Ed Foote, I imagine image 3 would be about "early enough to keep the hammer out of the string's excursion zone" and that image 4 or before would be "as late as possible to offer the least interference to pianissimo playing".

To me your qualified answer looks to be spot on, Jim.

Thanks to you, JLG, for starting this thread and to one and all for your pointers.

by feel, as you do, (it is not so fast, just "fast enough") but it is no surprise then to see the jack having a hair of move up before moving front (hammer out of the way)

if the 2 contacts where synchonized we would expect to see the jack moving immediately front as soon the drop screw touches the leather, so for some time I did not understand where that motion came from.

of course wen the rest felt is old and hard less or no up move is seen (the only motion up remaining equates the play between jack top and lever) it makes an approximate regulation, but easy to do, also it is easy to notice wher the drop scew have been screwed too far

The thing is that when you regulate the jack on the knive line (for instance) at rest, chances are that in normal playing it will be located back the line a little

The more the jack is back, the more it will get pressure from the knuckle before moving

That is how Renner action can work with little letoff and very small drop

I'm trying to understand what you are seeing here.

So, I take the action out of the cavity, swing the hammer out of the way. The knuckle is now not sitting on the jack/repetition lever. Then I run the key through letoff. When the key is depressed slowly I see the jack rise first then move forward. When the key is depressed in a manner more approximating normal play, I don't see the rise. I can't tell whether I don't see the rise because the event is too fast, or because the jack is longer rising (or rather the rep lever is not being depressed before the jack moves.

However, we have artificially taken the hammer out of the picture for this excersise. Is that a fair way to view the event?? I ask this more as question rather than a challenging statement.

With the hammer in its normal rest position, with knuckle sitting on the jack/rep lever, the rep lever will be depressed more than the above artificial demonstration, thus delaying the rep lever/drop screw contact just a hair. Maybe eliminating the non-synchronicity you are mentioning. No?

Also, in different velocities and forces of play, the timing will have to migrate just a bit as well.

Jim Ialeggio

ps. yesterday was called to do a grand "voicing", nice piano. As usual I don't voice a nice instrument without doing a picky-ass regulation. Once again...it never ceases to suprise me...by the time I was done with the regulation, we decided it didn't need the hammers touched. The regulation voiced the instrument. This doesn't always happen, but darn, it sure happens way more often than one would intuitively expect.

Jim, I like your last sentence, it is useless to voice an action out of regulation, and it happen that voicing is hiding some hardness of tone due to regulation.

Control on the hammer/tone is all the pianist want (and hammer energy is fragile, even if plenty of reserve is availeable for some time) THe same happens after hammer shaping, the tone is bright and too bright, but it is generally not necessary to needle much as long as the tone is long and pianissimo controllable.

About what we see of the jcak with the shank up, We see first sometime a different rest position, because the pressure from the knuckle push (more or less depending of geometry and indeed the cushion resiliency) the jack on its cushion (at rest)

Just for that the move of the jack toward front is a little delayed

Then we also see the amount of play (a paper thickness) left between the lever and the jack.

Then, when the action is played normally at the beginning of the stroke, the rolling pressure coming from the knuckle push the jack on the cushion (again, depending of the lining, the pressure will be more or less strong)

But those components must be even from note to note, so it is a good tip for the ones that have not learned the specialized touch necessary to feel the clear bump of the jack. It also allow to detect inconsistencies (most often drop screw left too screwed)

If we leave the jack a little back, the letoff/drop regulation is easier to feel because we feel a "strong" wedging effect when the jack (under the pressure of the knuckle) is stopped by the letoff dowel . even when the jack line perfectly at rest this occur if the hammers are heavy enough.

I suspect that when the jack is left at the middle of the knuckle at rest, when the note is played it goes back enough to be nearer the edge of the core than we suspect (if not we would have more cheating jacks)

The action is faster then, as the jack go toward the keyboard easily, there is also less pressure on the cushion, as if the jack floated, but what makes the tone change is due to the half mm we gain on the 31-32 mm leverage from top of the jack to hammer center (my guess) The shank is accelerated faster, possibly (also) because there is less lost of motion in direction of the jack cushion.

This is really only for some actions, but can help a too "heavy-grounded" tone .

ABout jack lining, the result is different and more precise if the job is done from the back of the action, the paralleled vision is not comfortable nor easy to obtain when looking from the keyboard side (plus I like to have my arm resting on the hammer rail quietly for the drop regulation, tactile feedback is exacerbated, a mirror is necessary to look at the letoff and drop then.