Ratio was 5.75 using the measured hammer rise vs measured key dip technique.
I changed bass to from 5.75 to 5.25 (3mm capstan move), up through the tenor. Graduated the capstan move from 3mm to 2mm within alto capo section. I left the top section at 5.75. This shift in ratio is common in older instruments, at least as best I can tell from vintage actions that have come into the shop. .
Dip stays at .390, aftertouch prioritized at .040, blow takes up the difference as necessary. Before the change, blow was 1-7/8 in the 5.25 sections, instead of the current 1-3/4, and aftertouch was a little strong of my target .040.
I'm doing the graduated leverages on this action, because I like how the high treble feels as it is. I can avoid too much back leading to reach my elevated treble DW's, if the ratio is slightly elevated. Down further in the compass, the elevated DW's I target don't work as well if there is too much lead in the keys, so I wanted to lose some lead. All of it is in the back half of the front lever, in the bass and tenor, but still too much to work with elevated DW's.
I don't do the 38g BW weight metric thing, and actually dislike the feel altogether, so I approach the whole thing differently. My approach is similar to what Ed McMorrow does, but not exactly the same.
I am looking for this combination of parameters in my actions:
1-Lighter hammers - HW 9-10g at note 1, with a simple linear slope to low 3g HW at 88...this graduation changes depending on what the manufactured hammer set will give me. Concert instruments note 1 elevated to 11-ish, but 88 still stays as light as I can get it.
2- As little lead in the key as is practicable. I want the finger to have un-encumbered connection to the movement of the hammer, and really dislike the lead imposing its opinion on the whole experience. There is lead, to be sure, but I said, as little as practicable. This will mean, no lead past the half-way point of the front key lever. This mostly means, during weigh-off, FW changes of 10-12ish g for the naturals, and usually a little more for the sharps( say 1-2 max 1/2" leads well in towards the balance rail.
3- Elevated DWs. Depending on the overall key length, (ie less for short key baby grands and more for longer key instruments), note 1 has about 60g for short key pianos, and 65-ish for longer key pianos. Graduating to about 50-53-ish g at 88 for all pianos. This higher DW, when a system is low inertia, provides the necessary resistance one needs to remain in contact and in control of the hammer, and does not at all "run away" from the fingers as is cautioned will happen. The experience is about the way the acceleration of the hammer per finger movement feels, as opposed to the way a static 38BW touchwieght feels, which to me is defined by how much I have to argue with the lead's inertia and momentum. It is different than a 38BW setup, since you are mostly accelerating the hammer, and not accelerating lead. BW's FYI are in the mid to high 40's, and is just not that meaningful in this kind of set up.
I say I don't use the standard BW metrics, because they assume as a design value, ie the value of lead in the key, which I don't subscribe to. Obviously the BW metrics work and make pianists happy, but so does this approach...so its a "many design scenarios can work" thing, as long the design scenario is internally consistent..ie, there is no one correct answer on how to proceed.
4- In designs, I standardize regulation parameters dip .390", aftertouch .040", blow 1.75", letoff varies between 1.5-2mm depending on the venue of the piano, and impose them, if the action is not set up to provide them. These standardized regulation parameters allow me to know that actions will be consistent and predictable piano to piano, and greatly simplifies the design process. If the regulation parameters are as targeted, and hammer weights as targeted, and the lead patterns as mentioned, all within a reasonable bandwidth, the actions will all have a reasonably consistent feel action to action. The standardization of all the above parameters takes the guesswork out of picture, in a similar way that the weight metrics seek to take guesswork out of the picture.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
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Original Message:
Sent: 01-12-2020 08:14
From: David Skolnik
Subject: Half Balance Rail Punchings for Leverage Adjustment
Jim -
So, to review (as in: please correct or clarify):
- in your above response you use the word 'capstan' in the singular, but is it correct to assume that you were dealing with the entire keyboard? If so, that would appear to be an equivalent amount of extra work.
- while you didn't specify, it would appear that the ratio was too high. What were the symptoms?
- what was key-stick ratio? length of front arm? rear (to capstan)?
- down and up weights (range)?
- to retain your dip and aftertouch, you had to modify your blow. What was it before and after?
- while you say that you don't observe Stanwoodian protocols (as per your post to the Key bushing Caul size thread as copied below), could you make any correlations to the parameters you expressed there?
I don't do weight balancing metrics aka Stanwood, or even use the data they generate. Rather, the system is low inertia at the hammer, slightly elevated system leverage, minimal lead, usually none starting mid notes of the 30's, all lead in back of the mid point of the front lever, with elevated DW, in the low to mid 60's in the bass graduating to mid 50's in the treble. (January 10 2020, JI)
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David Skolnik [RPT]
Hastings-on-Hudson NY
917-589-2625
Original Message:
Sent: 01-11-2020 20:28
From: Jim Ialeggio
Subject: Half Balance Rail Punchings for Leverage Adjustment
Hi Nick...I bagged it and moved the capstan 3mm. Turned out this also lined up better with the heel center, so it was a win-win. As you mentioned,and as I have seen when experimenting with this balance punching thing, ratio adjustment from this move is really pretty "meh", technically speaking.
Moving the capstan, actually all I have to re-regulate is the blow/hammer line to meet my already set dip/aftertouch. This leaves all the foundation conditions intact as well.
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Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
Original Message:
Sent: 01-11-2020 17:07
From: Nicholas Gravagne
Subject: Half Balance Rail Punchings for Leverage Adjustment
Doesn't it [the half punching] just sustain the initial ratio through completion of the keystroke?
Yes it does, even better than the original setup. However, it is better to think of this modification as optimizing the key ratio, not changing it. The typical key sitting on flat, flexible washers of paper, cardboard and felt does not pivot cleanly at a single point, but rather rolls over what amounts to a number of points. Keys pivoting on the Steinway accelerated action bearings do better in this regard.
The half-punching defines a definite ledge precisely at the key's pivot point resulting in a crisp and uncompromised rotation as compared to the rather inexact rolling action it otherwise undergoes. The key, if you will, is happy to "fall off the ledge" at the slightest provocation of the pianist.
It is even possible to locate the cut (or half-moon) punchings behind the balance pin. This, then, will change the key ratio and noticeably increase the mechanical advantage of the key. The motion taking place at the key pin and balance hole, however, involves some sliding. See Mario's book, page 313 for more info on this.
Friction may also be lowered a bit, but I have not quantified this.
Worth a try, Jim. Don't know how much of a mechanical advantage you hope to gain.
Good luck. -- Nick G
Original Message------
Jim,
I'm on my phone so won't get into extended discussion about the leverage aspect now. Regarding key level, since I don't have a Chris Brown bench and don't trust my ability to duplicate the keyed will enough, I set samples (C's and maybe G's) using split punchings and the fill in on bench using a light 1/2 octave stick. You could retain (as in: don't modify) samples until you've completed the rest, then do the samples. That would be a little harder using Karl's veneer method but you could figure it out.
Doesn't it just sustain the initial ratio through completion of the keystroke?
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David Skolnik [RPT]
Hastings-on-Hudson NY
917-589-2625
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