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Letoff/Drop regulation

  • 1.  Letoff/Drop regulation

    Member
    Posted 11-18-2021 20:04
    I have seen different people say that they regulate a grand action so that the toe of the jack touches the regulating button at the same time that the drop screw contacts the repetition lever (or balancer).

    Two questions:

    1. How does one test to know that this is happening while regulating?
    2. What is the change in feel to the action if this does or does not happen?

    ------------------------------
    Rex Roseman
    Akron OH
    330-289-2948
    ------------------------------


  • 2.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-18-2021 20:12
    We do that by the amount of drop. The acceptable distance is 1/16" below let off. 

    We call it the drop screw, but technically it should be called: "the screw that starts pushing down the balancier at the exact moment the jack touches the let off button".

    ------------------------------
    Willem "Wim" Blees, RPT
    St. Augustine, FL 32095
    Tnrwim@aol.com
    ------------------------------



  • 3.  RE: Letoff/Drop regulation

    Member
    Posted 11-18-2021 20:22
    Wim

    Thank you. That is what I have been doing. I just didn't realize what was happening in those terms. Thank you for the clarification.

    ------------------------------
    Rex Roseman
    Akron OH
    330-289-2948
    ------------------------------



  • 4.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-18-2021 23:00
    Well, Wim's nomenclature really only describes its own motion, disconnected from the motion it transfers to other parts. It is connected, The drop screw is what serves as the resting point the hammer will descend to during aftertouch. That point is fixed at the drop screw by the rep spring underneath it and the only other way the knuckle-balancier contact can change is if the capstan changes its lift under the wippen body.

    So , it's the "drop screw" because it determines the maximum drop the hammer is allowed. The hammer has to drop below LO, but the "fatter" drop is, the worse deep-repetition gets.

    ------------------------------
    William Ballard RPT
    WBPS
    Saxtons River VT
    802-869-9107

    "Our lives contain a thousand springs
    and dies if one be gone
    Strange that a harp of a thousand strings
    should keep in tune so long."
    ...........Dr. Watts, "The Continental Harmony,1774
    +++++++++++++++++++++
    ------------------------------



  • 5.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-18-2021 20:19
    1.) It's best seen on the bench. Keep your eye simultaneously on the top of the jack and the back of the rep lever. Each of these will signal their respective motion, when they contact their adjusting button.

    2.) Both the jack and the rep lever will be pushing against the butterfly spring (the jack at the LO button, and the latter, the drip screw). If they hit at the same time, this make the escapement crisper. If they don't, the escapement will seem softer or out-of-focus, depending on how the pianist likes escapement to feel.

    This simultaneity isn't always possible, even on a piano whose designers intended it, kind of like jack-knuckle alignment in which the knuckle mouldng and the back of the jack is supposed to form a straight line, but many times doesn't.

    ------------------------------
    William Ballard RPT
    WBPS
    Saxtons River VT
    802-869-9107

    "Our lives contain a thousand springs
    and dies if one be gone
    Strange that a harp of a thousand strings
    should keep in tune so long."
    ...........Dr. Watts, "The Continental Harmony,1774
    +++++++++++++++++++++
    ------------------------------



  • 6.  RE: Letoff/Drop regulation

    Posted 11-18-2021 22:02
    Like William Ballard said.  Lift the hammers up out of the road to see what is going on.  As you lift the back of the key, or push on the back check, the top of the jack should not begin to move horizontally before the repetition lever surface contacts the drop screw.  On the other hand, horizontal movement of the jack should be immediate, and not delayed, in relation to repetition surface/drop screw contact.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 7.  RE: Letoff/Drop regulation
    Best Answer

    Posted 11-19-2021 00:48
    Look up the video "You Don't Know Jack" by Nathan Mills on FB or Youtube. Regulate let-off, then put the action on a table or workbench, stand on the backcheck side, lift all the hammers forward away from the stack, individually lift 1 key and look at jack, if the jack tender rises then moves forward then the drop screw is too low (too much drop), turn it counterclockwise to raise it up.

    If jack tender moves forward then starts rising up then the drop screw is too high (not enough drop which would have made it difficult or impossible to adjust let-off beforehand), turn it clockwise to raise it up.

    You want to see 1 motion from the jack tender, not two (not up and forward, or not forward and up).

    Of course if you are having a hard time seeing this asjust drop way low on one note and then you'll see jack tenser rise high up before moving forward when you test it.

    I'm not sure how it feels, maybe try this test so you can see for yourself: adjust 10 consecutive notes' drop a tad lower than usual (maybe ¼" hammer drop), adjust 10 so that toe and rep lever hit button and screw simultaneously, and adjust 10 so that drop is a tad higher than usual (make it the same distance away from string as let-off...so, no hammer drop at all). Then play each group of 10 and see for yourself how it feels.

    ------------------------------
    Cobrun Sells
    cobrun94@yahoo.com
    ------------------------------



  • 8.  RE: Letoff/Drop regulation

    Posted 11-19-2021 10:50
    As with all regulation there is a circle of refinement. to really set the height of the Repetition Lever Upstop Screw, the action needs to be fully 'regulated'. To set an even height, the key dip/after touch needs to be set. After the Let Off has been adjusted, you can time the Upstop Screw by lifting the end of the jack to touch the button.
    Adjust the Upstop Screw to contact the Repetition Lever when the jack toe touches the button. Confirm by lifting the rep lever to touch the screw and see if you can move the jack higher. Another method is to lift the jack to the button and you'll notice slight motion (or not) at the back end of the rep lever. Then notice the distance the hammer resides from your Let Off Guide at full key dip. Set an equal space below the L/O line for the section.  The TLRG (Pianotek pg. D-13) is a great tool, I use it exclusively :-)

    Having the two contact simultaneously develops a cleaner, crisper after touch with their respective springs engaging same-ole-timeously.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 9.  RE: Letoff/Drop regulation

    Posted 11-22-2021 16:16
    I'm sitting here with my head in a piano asking myself if the ideal is always possible.

    The piano is a 1988 Young Chang G-157.  Knuckles are newer than everything else in the action, replaced maybe 6 years ago, not badly worn.  Let-off is close enough that I can play off of the jacks, but not so close that the hammer interferes with the motion of the string when sounding loudly. Drop is minimal.  I'm looking in particular right now at the top note of the overstrung section.

    The surface of the repetition lever touches the drop screw, and the repetition spring begins to compress.  The jack does not immediately deflect horizontally--it rises slightly first.  I see three options.  I can raise the drop screw, but drop is already minimal.  I would need to eliminate it altogether.  I can lower the regulating button, but I kind of like being able to play off of the jack.  I can allow the jack to be at rest further under the knuckle, but it is already aligned appropriately with the core, and I don't want to increase the friction of the jack scrubbing on the bottom of the knuckle.  There's enough of that already.  Yes, I know I can teflon the knuckle, but not everybody is willing to do that.

    If the ideal is not possible in this situation, then I have a question I'm trying to figure out:  What exactly is it in the design of an action that either enables or prevents this degree of precision in the timing of the regulation?

    Or am I missing something obvious?

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 10.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-22-2021 16:31
    Floyd

    This is what I learned from Eric Schandall at Steinway. With all the other adjustments made, stand at the back of the action, (or turn the action around), and lift the hammer out of the way. Slowly push down on the key. The top of the jack should move towards you, (away from the front of the piano) at the same time it rises. If it rises first, before moving forward, lower the drop screw. It should take less than half a turn to get the jack to move forward and up at the same time.  I'm not a player by a long shot, but when I did that to an action, and played the piano, it felt more "solid".

    ------------------------------
    Willem "Wim" Blees, RPT
    St. Augustine, FL 32095
    Tnrwim@aol.com
    ------------------------------



  • 11.  RE: Letoff/Drop regulation

    Posted 11-22-2021 17:02
    Wim, if it rises first, lowering the drop screw will exacerbate the problem, not resolve it.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 12.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-22-2021 17:17
    I'm sorry, it's been a while since I've regulated a grand action, and I'm trying to visualize what I'm supposed to do sitting in my Lazy Boy.
    Obviously, I got it wrong, so do the opposite.

    ------------------------------
    Willem "Wim" Blees, RPT
    St. Augustine, FL 32095
    Tnrwim@aol.com
    ------------------------------



  • 13.  RE: Letoff/Drop regulation

    Posted 11-22-2021 16:32
    I'm gonna have to join Floyd on this question. Anyone? How is an action designed so that one could or could not get simultaneous contact of the drop screw and jack toe?

    Also, how close can we/should we get drop to let-off? I know we don't want a hammer bobbling on the string if it pops out of check and the repetition springs pushes the repetition lever/hammer back up to the string. But if simultaneous escapement (rep lever and drop screw/jack toe and let-off button) happens and let-off and drop are the same distance from the string but there is no bobbling from the drop being too high then is that a bad thing to leave drop that high?






  • 14.  RE: Letoff/Drop regulation

    Posted 11-23-2021 06:42
    I suppose maybe it boils down to parts wear.  The hammers in the action I am looking at have been filed, such that the bore distance is now less that what was original.  I noted above that increasing let-off would resolve my problem, but that I was unwilling to sacrifice the ability to play off of the jack (a phenomenon referred to in another thread as ghosting the tone.)  If my bore distance was longer, the "compromised" let-off distance would not be compromised at all.

    I usually find that the issue in trying to coordinate the bump is in the direction I have described above -- the jack rises before it begins to move horizontally.  So I propose that a key element of design that enables or prevents coordination of the bumps is bore distance, and that most of the problems I run into are not, in fact, design problems, but rather a consequence of hammer wear.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 15.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-23-2021 08:00
    Floyd Gadd went: "the jack rises before it begins to move horizontally."

    We probably need to be clear about what's happening. The jack isn't rising; it's the rep lever which begins to lower as soon as it contacts the drop screw. (Kind of like, does the spring-driven rep lever throw the hammer upwards during actual play (the way we see it while setting rep spring strength)? No, quite the opposite, it throws the rep body and the key downwards.)

    To recap, 1.) when the jack  tender hits the LO button, it moves forward (towards the keyboard) and 2.) when the rep lever hits the drop screw, it moves downwards



    ------------------------------
    William Ballard RPT
    WBPS
    Saxtons River VT
    802-869-9107

    "Our lives contain a thousand springs
    and dies if one be gone
    Strange that a harp of a thousand strings
    should keep in tune so long."
    ...........Dr. Watts, "The Continental Harmony,1774
    +++++++++++++++++++++
    ------------------------------



  • 16.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-23-2021 06:44

     

    Can you reduce keydip/aftertouch at all? That would allow you to raise the drop screw.






  • 17.  RE: Letoff/Drop regulation

    Posted 11-23-2021 07:13
    The issue here is that drop is already so minimal, that raising the drop screw would eliminate it altogether. Cobrun has raised the question as to whether this is in fact an option.  I think your point, Mark, is pertinent to his question, but otherwise, keydip and aftertouch operate independently from this coordination of the bump.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 18.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-23-2021 07:56
    With less dip, the hammer will "drop" more after escapement, which will allow you to raise the drop screw.

    I like to have the hammer drop slightly but positively below let-off. I've also backed off setting let-off as close, but not so much that I can't still play off the jacks.

    ------------------------------
    Mark Dierauf
    Concord NH
    603-225-4652
    ------------------------------



  • 19.  RE: Letoff/Drop regulation

    Posted 11-23-2021 09:20
    The jack does protrude above the rep lever thru escapement. That's the way it works. I have never seen it not do that.

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 20.  RE: Letoff/Drop regulation

    Posted 11-23-2021 09:27
    Re simultaneous escapement, this is an adjustment where, an action, even if it designed perfectly, will still feel awful, mushy and hard to predict , until the two are timed to a single crisp bump.

    The problem often comes, as is being mentioned, what do you do, when simultaneous escapement is just right, but it leaves drop too high. Drop too high meaning, either, there is no feeling of letoff anymore, or when pressing the key into the front punching, it blocks the string (will result in a double strike)?

    Many actions because of the parts design and relationships, will not allow a super high letoff, ie the kind of high letoff folks teach concert regulation requires.  In this case, you must lower letoff a tad. The geometry will not allow letoff to be that high and still achieve simultaneous escapement. One proves simultaneuos escapement and letoff height on a sample key or keys, before setting letoff.

    The double escapement is so important,  it takes precedence over super high letoff. Like Mark, I have backed off my letoff height, both in response to most actions asking me to lower letoff a tad as described above, and also, because very, very, very few actions receive concert level attention to regulation changes...lets be real...

    The other thing is, that with hammer weights that are not off the deep end, super close letoff is not necessary. This means super high letoff becomes  superfluously problematic. My letoff is 2mm these days, maybe 1.5mm if I know the action will be looked after regularly, like a good recording studio. 

    The other problem with super high drop, is it will kill checking dead. Checking depends on getting the rep lever and its nasty little spring, out of the checking picture in time for checking to occur. PPP checking can be difficult, because the stroke happens so slowly, relative to a mf or f blow, that hammer rebound happens, before the rep spring has been compressed, thus failing to get the rep lever out of checking's way.


    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 21.  RE: Letoff/Drop regulation

    Posted 11-23-2021 11:08
    Thanks Jim.  You're helping me evaluate my priorities.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 22.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-24-2021 02:24
    I might be bending this thread away from its original question, but...
    In staring at my action model I see the knuckle rotating quite a bit during hammer/shank motion.  The set-in-stone rule of jack lined up with the back of the knuckle core seems to make sense with the hammer in its lower, rest position, where the jack is centered in line with the apparent direction of force, but as soon as the hammer begins to move the knuckle rotates and the center of force of the jack is not necessarily in line with the center of the jack.
    There are admonitions to properly position the jack to prevent excessive wear or to prevent too easy or too hard escapement and excess wear.
    Who has experimented with deeper jack positioning (1/2 mm or less)?
    How do you sense the changes in playing and feel?  How  do you think it affects the issue of drop regulation and drop screw vs let-off button contact?

    ------------------------------
    Blaine Hebert
    Duarte CA
    626-795-5170
    ------------------------------



  • 23.  RE: Letoff/Drop regulation

    Posted 11-28-2021 04:15
    Blaine, I just thought about this too. And although the knuckle is sliding back further towards the inside of the piano I would venture to say that the force from the jack is still angled at near the center of the knuckle (although not in direct alignment with where the knuckle attaches to the shank by the stem). I think I saw somewhere in Igrec's Pianos Inside Out that there are 2 types of frictions going on at the contact between the jack/rep lever and knuckle. There is the physical contact and friction between the jack/knuckle and the contact and friction between the rep lever/knuckle. But then there is also the friction of motion in that wippen is rotating on its flange and the hammer is rotating on its flange. At key rest both angles of the wippen and hammer are slightly off in that when they start traveling at the beginning of a keystroke they are not moving parallel to each other at the jack/rep lever/knuckle contact point.

    But, as the hammer nears the string the jack/rep lever/knuckle are at their closest to traveling parallel to each other allowing for greatest transfer of force from jack to knuckle with less force being lost due to non parallel travel and less motion friction.

    But also, Mike Reiter in his Relentless Repetition class mentions that during a hard blow the jack will actually follow the knuckle backwards a little bit towards the inside of the piano (towards the hammer) before the static friction between the top of the jack and knuckle release and the knuckle continues sliding backwards as the jack repositions itself before being tripped by the let-off button.

    So, as far setting the jack deeper? I don't think it would be useful.

    ------------------------------
    Cobrun Sells
    cobrun94@yahoo.com
    ------------------------------



  • 24.  RE: Letoff/Drop regulation

    Posted 11-23-2021 11:05
    Mark, when I am setting/measuring drop, I am not pressing the key to full dip.  I am only moving it far enough that the drop of the hammer can be observed.  I do recognize that the amount of dip/aftertouch will determine how much closer the hammer moves toward the string with the key fully depressed, and that that is an important consideration in terms of performance, but in the terms of reference I am using, drop is not defined at end of key stroke.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 25.  RE: Letoff/Drop regulation

    Posted 11-24-2021 09:18
    Its interesting that folks look for secondary evidence of where drop is adjusted, always after letoff or at the end of the stroke.

    I don't do this. I only take the key to the point where the synchronicity is felt, ie, just to the point where the  jack tender touches the letoff button, and where the re lever touches the drop screw. Since this is what the pianist will experience, I work to the feeling of synchronicity at the pianist's end of the key.I work the key, from the pianist's position, approaching that point, with wrist resting on non-played keys, played with a finger, bringing the action to that point repeatedly at about mf speed.  I don't go through letoff, but just to the point where the finger feels synchronicity. 

    In this way, drop/synchronicity, can be tested and adjusted, outside of the piano, regardless of whether dip has been duplicated or not. In the rise of the hammer technique, on the other hand, the hammer rise represents secondary evidence, and requires that dip has been accurately reproduced, which is a pain, without the right setup.

    In my own case, since I have a dip duplicating table with string height gantry, the action is on the dip table, dip is already duplicated, and I have the string height gantry in place. So I know where string is. After I find the synchronous point, before letoff, which does not depend on dip, I check, at full dip, with punching compressed, that the hammer is safe from blocking the string. I do both the synchronicity test and the final hammer-not-blocking-the-string test on each note, as I progress. In this way, I can see, after one or two notes, ie, before I've gotten through 75 notes, whether I have gotten letoff right for this action, and can safely proceed to set drop as high as geometrically practicable.

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 26.  RE: Letoff/Drop regulation

    Posted 11-24-2021 12:56
    How are letoff and drop felt by the pianist?  Is the feeling of drop anything other than synchronicity, the absence of gross movement of the hammer after letoff, and the presence of checking due to the clearance created?  Is the feeling of correct letoff anything more than absence of interference between hammer and string, consistent key dip and aftertouch, and thus a consistent length of power stroke as experienced at the front of the key?  How much does the ability to play a consistent pianissimo depend on some particular proximity of letoff to the string?  If you achieve everything else, but have a variability of even a couple of millimeters in letoff across the scale, what has been lost?

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 27.  RE: Letoff/Drop regulation

    Posted 11-24-2021 13:59
    I guess another dimension of the feeling of letoff for the pianist is the tactile sensation of the surface of the jack dragging across the knuckle.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 28.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-24-2021 17:53
    The bump of LO tell the pianist that any further pressing on the key is wasted, and their fingers should be thinking about the next notes to be played.

    ------------------------------
    William Ballard RPT
    WBPS
    Saxtons River VT
    802-869-9107

    "Our lives contain a thousand springs
    and dies if one be gone
    Strange that a harp of a thousand strings
    should keep in tune so long."
    ...........Dr. Watts, "The Continental Harmony,1774
    +++++++++++++++++++++
    ------------------------------



  • 29.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-24-2021 23:50
    There might be more to this than just good lubrication.

    At a recent NAMM show Steinway has a  "special" B on display.  Aside from having an unusual piant job when I played it I was startled at the touch; they had lubricated it to the point that it felt like an electric keyboard (interesting that no one else I talked to noticed)!

    I have not experimented with using a toothbrush or wire brush to rough up the knuckles but creating a controlled surface for the jack to move on shounds intriguing.

    Perhaps there is more to the feel of a new piano than we admit.

    ------------------------------
    Blaine Hebert
    Duarte CA
    626-795-5170
    ------------------------------



  • 30.  RE: Letoff/Drop regulation

    Posted 11-24-2021 19:59
    whoowee...down boy...them is a lot of questions...

    For me, the feel of letoff, defines the action. The feel means, you want a clear sense that letoff is happening, but you do not want it to be a wall of friction, and do not want it to be an event of long duration. High drop reduces letoff friction. Really high drop makes the sensation of letoff go away entirely. So, as you gradually raise drop, you also gradually reduce letoff friction.

    Heavy hammers, accentuate the friction in letoff, and extend the letoff event (not beneficial in my view). The heavier the hammers get, the higher letoff has to go, in order to get drop as high as possible, so letoff is not a wall of friction. Its all connected, hammer weight, leverage, letoff distance from the string, drop, letoff friction. 

    My take is that drop is more than synchronicity. As I just described above, it is also about letoff friction. Synchronicity creates a very clear initiation of the letoff event, and the shortest letoff event that action is capable of...they both are about the sensation of letoff, one about friction the other about clarity and duration of the event. The two define the feel of letoff, which defines the feel of the action to a great extent.

    Ability to play consistent pianissimo is relative to the leverage of the action and weight of the hammers. The heavier they get, the closer to the strings letoff needs to be, and the higher drop needs to be, to control letoff friction. These actions push the limits of the system to the max, and are high maintenance. Reasonably weight hammers, and slightly elevated leverage, allow letoff to be lower, drop to be lower, and maintenance to be lower. They both help ppp playing, but the systems behave differently. So, there is, in my view, no single answer to the ppp part of your question. Just to be aware of the weight/leverage aspect of the action you are working on, and work to that action's requirements.

    Consistency across the keyboard is felt as an intuitive connection to the action. A couple of millimeters in letoff, is miles. Keeping in mind when letoff is that inconsistent, the letoff friction will vary, etc etc etc. When the action lacks consistency, the player's mind has to process insane amounts of data for each and every key. When there is consistency the brain has much less data to decode regarding the machinery of the action. Consistency means that there is more brain space available to the player to musically navigate the music instead of spending all its resources trying to out guess the action's recalcitrant machinery.

     




    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 31.  RE: Letoff/Drop regulation

    Posted 11-24-2021 20:19
    I was baiting you, Jim :-)

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 32.  RE: Letoff/Drop regulation

    Posted 11-24-2021 20:24
    Thank you for taking the time to craft this answer. I'm going to need to study it for a while.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 33.  RE: Letoff/Drop regulation

    Posted 11-25-2021 00:51
    I've found synchronistic contact of drop and let off most important.
    One method is to use a gram weight slightly above down wt.
    Say DW is 50g, use a 55g weight, with dampers up or action on the bench, let off set, drop too low.
    The 55 will raise the wip to the drop screw at which point the wip will stop rising, then raise the drop screw and watch the hammer rise,
    as soon as the jack tender makes contact, the hammer will stop rising, pinpointing simultaneous contact.
    This assumes friction with in bounds, say less that 15. I am able to very quickly set drop using this method.

    ------------------------------
    Fenton Murray, RPT

    Fenton
    ------------------------------



  • 34.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-26-2021 07:02
    Brilliant! Thanks for posting this tip, Fenton.

    ------------------------------
    Mark Dierauf
    Concord NH
    603-225-4652
    ------------------------------



  • 35.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-25-2021 06:55
    Jim said: I only take the key to the point where the synchronicity is felt, ie, just to the point where the  jack tender touches the letoff button, and where the re lever touches the drop screw.

    Exactly. But then having done this one can adjust the final position of the "dropped" hammer relative to the string with FR punchings rather than by further adjustment of the drop screw.



    ------------------------------
    Mark Dierauf
    Concord NH
    603-225-4652
    ------------------------------



  • 36.  RE: Letoff/Drop regulation

    Member
    Posted 11-26-2021 09:17
    Mark, could you describe how you adjust the final position of the dropped hammer with FR punchings, please? I'm not seeing this because if you take a punching out, you'll be pushing the hammer closer to the string after let-off/drop, and if you add a punching, you're impinging on aftertouch.

    Another general question with let-off/drop being simultaneous and close to the string: doesn't this then depend on repetition lever strength and checking height to prevent bobbling on soft notes?


    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 37.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-26-2021 17:59

     

    Yes, of course it impinges on aftertouch, but if the hammer is rising after (simultaneous) escapement than there is excess aftertouch.






  • 38.  RE: Letoff/Drop regulation

    Member
    Posted 11-26-2021 18:35
    Well this brings us back to lack of clear standards: I was taught that there should be slight hammer rise after escapement (when a key is played slowly so as not to check) as a sign of adequate aftertouch. If there's no hammer rise, then is there aftertouch? I'm just stating the logic of what I was taught.

    I was also taught that drop should be 1/16 below let-off; yet again I was shown by a very experienced tech that drop should be more than this (about double-- that really threw me off but of course I had to assume that that was correct information.) Simultaneous escapement makes sense. And granted, there may be a distinction between standards for the casual player and for the concert pianist.

    Not to criticize: I think this is a great discussion and the point is to clarify what's going on and what we should be shooting for. I'm here to learn.

    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 39.  RE: Letoff/Drop regulation

    Posted 11-26-2021 19:41
    <I think this is a great discussion and the point is to clarify what's going on and what we should be shooting for.

    The point of the discussion, in my mind, is to clarify what the adjustments are actually doing, not to formulate a one size fits all recipe. 

    Reading back though the various posts, folks are responding with the "Why?" of what this adjustment is about. If you know the "why?" you can, with thought and experimentation, figure out the "what". The "what" changes with each action, with hammer mass, with leverage, with knuckle condition, and with what the client has chosen to afford. 

     


    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 40.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-25-2021 09:13
    Jim,

    Would you be able to  describe the  "dip duplicating table" you mentioned?  Thanks

    David

    David Weiss
    Registered Piano Technician
    (434) 823-9733
    davidweisspiano@gmail.com
    www.davidweisspiano.com

    ------------------------------
    David Weiss
    Charlottesville VA
    434-823-9733
    davidweisspiano@gmail.com
    ------------------------------



  • 41.  RE: Letoff/Drop regulation

    Posted 11-25-2021 12:28
    Here's a video from Jim:   https://youtu.be/hiVWoRWprlE

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 42.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 11-25-2021 18:28
    Has anyone used a tool like La Roy Edwards grand let off tool?
    https://www.youtube.com/watch?v=4EYb904oDpk

    ------------------------------
    Steven Rosenthal
    Honolulu HI
    808-521-7129
    ------------------------------



  • 43.  RE: Letoff/Drop regulation

    Member
    Posted 11-26-2021 08:59

    Edward's grand let off tool is very similar to "the stick" I learned from Jim Busby. A simple wooden stick about 3/4 square, approximately 14" long with sandpaper on one side for friction. You have to set let-off first on two end hammers on each side of a section to be adjusted (four hammers total.) All hammers in a section are then raised except one on each end (whose let off has been set) and the stick is placed on these end-most hammers. Hammers are then lowered onto the stick and the stick is adjusted back-forth so that the other two end hammers (whose let-off has also been set and which also sit on the stick) just wink when the keys are depressed. Set other hammers to wink. Easier than it sounds. Fast and very accurate for a first pass.



    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 44.  RE: Letoff/Drop regulation

    Posted 11-26-2021 13:15
    It should be mentioned, using a straight edge with end samples for let off requires bore distance to be consistent.

    ------------------------------
    Fenton Murray, RPT

    Fenton
    ------------------------------



  • 45.  RE: Letoff/Drop regulation

    Posted 11-26-2021 13:26
    Gee, this thread has gone on long enoigh so I might as well add more fuel:

    I know there are many ways to get let-off, La Roy/Spurlock jig (outside-of-piano hammer-winking method), Tautline tool/let-off jig (outside-of-piano rack-like tools), distance gauge like Yellow plastic one from Pianotek or 26 gauge wire or magnetic strip (inside-piano distance tools), ghosting/tactile method (hold damper up pound note and quickly bring hammer back up to the point of let-off to see if string buzzes)(inside-piano by-feel method).

    My question is what do you all use? Which way is quick despite not being accruate? Which way is accurate despite not being quick? Which way is both quick and accurate? Does doing the ghosting method leave let-off too close? Too far? Too inconsistent?






  • 46.  RE: Letoff/Drop regulation

    Posted 11-26-2021 13:43
    TautLine (TLRG), quick and accurate. Of course :-)

    ------------------------------
    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
    ------------------------------



  • 47.  RE: Letoff/Drop regulation

    Posted 11-26-2021 22:03
    Jim, your statement that higher le toff and drop mean lower friction made me think.  I stared at an action for quite a while before it occurred to me that the higher these are set, the farther back the knuckle is in relation to the jack when the repetition surface stops bearing the load of the hammer assembly.  That had never occurred to me before.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 48.  RE: Letoff/Drop regulation

    Posted 11-26-2021 23:32
    I did a video synchronizing the jack with the rep lever. I filmed it up close so you can clearly see the movements involved when the drop screw is either too high or too low, and when its correct.
    https://www.youtube.com/watch?v=P28hinc7Cro

    -chris

    ------------------------------
    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
    ------------------------------



  • 49.  RE: Letoff/Drop regulation

    Posted 11-27-2021 12:18
    One peek is worth a thousand words.

    Virus-free. www.avg.com





  • 50.  RE: Letoff/Drop regulation

    Posted 11-27-2021 08:43
    <the higher these are set, the farther back the knuckle is in relation to the jack when the repetition surface stops bearing the load of the hammer assembly. 

    That's right. But friction of letoff  is also determined by how much of the letoff event has the jack entirely supporting the knuckle, with no help from the rep lever (high friction), as opposed to how much of the letoff event, the rep lever and jack are both sharing support of the knuckle.

    The high friction scenario is the condition that occurs when drop is low. Low drop takes the rep lever completely out of the equation, for more of letoff, leaving the jack, and eventually the just the back edge of the jack, (high point load), to carry the entire compressive and scraping load. And, remember, in low or relatively low drop, that compressive and scraping load occurs while the high leverage shank/knuckle system is under considerable acceleration. This acceleration really accentuates the compressive and friction forces, especially if the jack is the sole support of the knuckle.

    When drop is higher, the knuckle is supported both by the low friction rep lever, and the higher friction jack, cutting friction in half (or something like half). Also, the rep lever/jack supported knuckle,has single point load contact of the jack (high friction), only, when the jack is way back on the knuckle, as you observed. Not only that, when the jack is that far back on the knuckle, it is contacting the knuckle, at a glancing tangent angle relative to the radius of the knuckle. So this tangent, relation of the jack to knuckle, is also lower friction, than the friction created, when jack is pushing closer to directly into the center of the knuckle. One is a glancing scraping event (tangent and lower friction), while the other, is mainly compressive, scraping for more of the event, and thus higher friction.

    This is why high hammer weights will be higher letoff friction, and require high letoff and very high drop.. All the forces I just mentioned, especially the low drop compressive forces of jack/knuckle, are greatly emphasized by the amount of weight on the end of a shank which has, in any shank setup, even a 17mm knuckle distance, a super high leverage. The high leverage of the length of shank, relative to the knuckle distance from the shank center, multiplies compressive and friction forces, by an order of magnitude. Small differences in hammer weight at the end of that lever are greatly magnified, as felt by friction at the jack, when the jack does not have the assistance of the rep lever through most of the letoff event (high drop).

    The last paragraph is also why, when you read descriptions on the journal, of regulation specs like drop, in a concert grand for a concert venue, they are calling for very close letoff and high drop. Hammer weights, and thus all of the compression/friction forces mentioned above, require those letoff and drop positions. A higher leverage but lower hammer weight scenario, as in the scenario we find in 95% of the actions we service,do not have those high hammer weight compressive/friction forces, and thus, will function quite well, with slightly lower letoff frictions at lower letoff and drop positions.

    edit...cleaned up syntax
    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 51.  RE: Letoff/Drop regulation

    Posted 11-27-2021 08:59
    edited and cleaned up my last post

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 52.  RE: Letoff/Drop regulation

    Posted 11-28-2021 04:55
    Okay, so this thought just occurred to me. Simultaneous contact can't be strictly observed with all hammers up out of the way and by solely looking at the top of the jack move in one motion (as described in Nathan Mills "You Don't Know Jack" video). I had mentioned up above, viewing action from the back and if jack "looks" like it moves up then towards player or towards player then "up" it means nonsimultaneous contact. I just realized that that isn't the case. In order to get true simultaneous contact, the hammer should be down on the wippen in its regular position so that it can put its proper weight onto the repetition lever (which in turn pushes the repetition lever down a smidgen).

    I tried Jim's way of finding simultaneous contact but I wasn't feeling it...I may not be accustomed to feeling that super light sense of touch yet. So I tried Fenton's way (using my finger as a surrogate "55g" weight) and by doing so I was able to get simultaneous contact. And when I looked at the drop distance it turned out to be roughly "by the books" 1/16". What a big change in measurement! A whopping 16th of an inch difference just by using two different methods of viewing something! Yikes.

    ------------------------------
    Cobrun Sells
    cobrun94@yahoo.com
    ------------------------------



  • 53.  RE: Letoff/Drop regulation

    Posted 11-28-2021 07:41
    Cobrun, if there is insufficient friction in the center pinning for the repetition levers, the repetition springs are going to need to be set too weak to prevent the rep levers from yielding to weight of the hammer assemblies at rest. This will result in the issue you are describing. With the hammer at rest, trip the jack manually. If the cushion on the adjustment screw for rep lever height visibly lifts from its bearing surface, the rep spring is set too weak.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 54.  RE: Letoff/Drop regulation

    Posted 11-28-2021 09:15
    Coburn,

    What was the condition of the knuckle when you were testing the various techniques. All of them, but especially the "feel" one I describe, becomes mushy to non-conclusive, if the knuckle is no longer a true radius, ie flattened out, even a little.

    So, the precision of touch, to a pianist, is dependent on the knuckle being a true radius. If its flattened, even just a little, all bets are off...Fine regulation cannot happen.

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 55.  RE: Letoff/Drop regulation

    Posted 11-28-2021 15:36
    Jim, this was on an action model with healthy new knuckles.

    ------------------------------
    Cobrun Sells
    cobrun94@yahoo.com
    ------------------------------



  • 56.  RE: Letoff/Drop regulation

    Posted 11-28-2021 15:48
    Floyd, this is on an action model. I adjusted the rep lever height so that the jack would slip out and in just barely/feel a little bit of scraping as I trip it out or in, I adjusted friction on rep lever center, checked spring slot, and adjusted tension for no feelable bump but still smart return during rep spring adjustment. I'd say that no matter how strong the rep spring is adjusted, the weight of the hammer will always affect it to some extent (maybe even to the most unnoticeable extent).

    I say this because during a hard blow the force of the wippen will fight against the weight of the hammer for a split second making it "seem" that the hammer weight instantly skyrocketed. In slow motion, during a hard blow, the rep lever will actually pop out of rest position ever so slightly and ever so quickly before resetting as the key continues to travel down.

    ------------------------------
    Cobrun Sells
    cobrun94@yahoo.com
    ------------------------------



  • 57.  RE: Letoff/Drop regulation

    Posted 11-29-2021 12:47
    Cobrun,

    It appears to me that you have the kind of grasp of the matters at hand that will allow you to move forward in the regulating work that lies ahead of you with intelligence and confidence.  One little detail worth thinking about.  In evaluating repetition lever height, take into account both your tactile awareness of the movement of the jack across the knuckle, and the winking of the hammer.  With the action at rest, trip the jack manually.  The hammer should just barely wink, demonstrating that the knuckle is indeed in contact with the jack, and the jack should return fully under the jack when it is released, confirming your sensation of that little bit of scraping as being . . .  uh . . . little enough.

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 58.  RE: Letoff/Drop regulation

    Posted 12-01-2021 15:07
    I'm thinking more about this, and wondering if I've got it right:

    The higher let-off is set, the less the jack needs to move to clear the knuckle, since the knuckle slides away from the top of the jack as the hammer shank is lifted.  If the jack needs to move only minimally, and the jack/button and rep lever/drop screw contact are synchronized, then the repetition lever spring will be only minimally compressed at the moment of let-off.  If the bore distance of the hammer is insufficient, either on account of original dimensions, or because the hammer has been filed excessively, setting let-off very close to the string can result in a scenario where the jack moves so little to accomplish let-off that the repetition spring is so minimally compressed  that drop is negligible.  Thus, the ability to achieve close let-off and still have measurable drop depends on a sufficient hammer bore distance.  Worn hammers limit how close let-off can be set.

    That was clumsy, but does it make sense?

    Would it also make sense that appropriate let-off and drop are functionally determined, such that a wide let-off dimension due to insufficient hammer bore length can still feel great to the player, because the mechanical components of the key, wippen and hammer shank assembly are in optimum relationship with each other?

    ------------------------------
    Floyd Gadd
    Regina SK
    306-502-9103
    ------------------------------



  • 59.  RE: Letoff/Drop regulation

    Posted 12-04-2021 16:50
    I just learned something yesterday, doing a full day regulation on one of my Bechstein rebuilds (B).

    Coburn tried to feel the synchronized bump of the letoff button touching the jack toe, and the rep lever just touching the drop screw. He said he couldn't feel it.  It is true, that sometimes the feeling of the clear "bump" when the two hit at the same instant, on some notes, can be ambiguous. While I was working on this Schwander action, which has that nice spring adjusting screw, and no bloody butterfly spring, I was getting a bunch of ambiguous bumps. Turns out, that if spring tension is too low, or too high, it makes the bump a non-bump. So, it was so easy to dial in the spring, while I was setting drop, each instance where the "bump" was ambiguous, became a clearly felt bump when spring tension was correct for that note.

    I really like this, because several adjustments self-check each other, and make clear when they are all correct for that particular collection of parts.

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 60.  RE: Letoff/Drop regulation

    Member
    Posted 03-28-2022 11:51
    I've experimented with simultaneous escapement on two pianos, one a Kawai KG-1A and the other my own piano, a Baldwin model M. I like the smoothness of touch with simultaneous escapement and the ability to play softly. I'll be working on a Steinway grand tomorrow adjusting drop on this for simultaneous escapement (I did conventional regulation with 1/16" drop earlier.)

    But I have a question about aftertouch as it seems to me that this has to be very minimal. My reasoning is that if let-off is 2mm and drop is simultaneous, one has very little room to maneuver AT. If, for example, AT measured at the key front is 1mm and if action leverage is approximately 6:1, then there's no way to get 6mm hammer travel after let-off. So AT has to be considerably less than 1 mm. Maybe I'm not understanding what's going on.

    The way I've been setting AT after setting simultaneous escapement is I've been pushing the key softly and watching for the hammer rise after escapement, such that the hammer doesn't hit the string or bobble, but does rise. This seems to require a delicate balance with repetition lever strength and, if necessary, slight differences in let-off. Eliminating bobble on soft playing seems to be the challenge with simultaneous escapement. It also seems that repetition lever height must ensure minimal friction on jack return, as in, the jack barely touches the knuckle.

    Does this make sense?





    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 61.  RE: Letoff/Drop regulation

    Posted 03-28-2022 12:32
    There are a couple things to keep in mind:

    1- this adjustment requires a round knuckle in good shape. Trying to pull this off on a well used action will cause all kinds of compromises. So, condition counts
    2- related to the above...a well used action simply cannot and should not be set to these really fine settings, because things like gummy rep lever grooves and worn checks, and probably miss-installed checks will rear their ugly heads.
    3- I measure  and prioritize After touch. The pianist feels this at the key, they do not feel it as much at the jack end of the setup. I measure with a .050 shim. How you measure is important, because the measurement technique influences the reading you get. I take a .040 plastic shim, cut a notch so it fits well around into the back area of the punching. Then, with blue tape, which . .005 thick, apply that tape to both sides of the shim, in a way that creates a tape handle. The tape handle needs to allow the shim to hinge between the handle and shim. Without this, AT will be more than I want, and inconsistent.
    4- increase dip to prioritize your AT, or  (edit)decrease blow. Neither of these will change your synchronized setting. The regulation dimensions, including dip and blow,  should be defined as what the action will allow, not what some regulation specs say the action should conform to.
    5- synchronized letoff, on many actions will bring drop high.  This means it will challenge check, which is the real 500 lb gorilla in the room on this fine adjustment. On a well used action, check will limit what you can pull off here. Its frustrating, but a fact. This is why, I said above condition counts. High drop, leaves the spring involved in check to a greater degree, and longer in the stroke, than low drop does...which is the reason really tired actions, with 1/2" drop check so well...really low drop, takes the spring entirely out of the equation.  Unfortunately, achieving decent (not great, but decent)check, will limit how precise you will be "allowed" to set synchronized letoff. Frustrating but true.

    This all works best on a new fresh action, so in talking about these adjustments, we really should differentiate between reality in the tired piano field, and new actions.

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 62.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 03-28-2022 14:53
    Jim,
    A good post and a reason I subscribe to these threads.
    On some of the new good German pianos I am servicing I see light spring tension, seemingly lighter than the factory's recommended speed of rise after check.  I have heard from others recommending light spring tension, though getting an accurate light tension is harder than getting it fast.
    I wish there was a simple and safe way to recondition worn hammer tails.  I have seen jigs that safely hold hammers in place to sand then without stressing the hammer flange but they are elaborate and more than I usually want to take into the field.  Spending time on backcheck angles and tail shapes is probably well worthwhile.  Figety worn backchecks require delicate tweaking.
    This subject of regulating worn actions (something that is much more common than regulalting new parts) is interesting and complex but important.  When a 1/8 turn of a letoff button changes letoff dramatically this is only due to the worn letoff felt and the regulation might not last (or it may go to disasterous blocking).

    ------------------------------
    Blaine Hebert
    Duarte CA
    626-795-5170
    ------------------------------



  • 63.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 03-28-2022 12:34
    Aftertouch can be measured directly, independently of how it may affect others things you want to infer it by. Decide the desided thickness of AT, get to cardboard front punchings and clip a slot in them so that they can be slid onto the FRP, on top of the felt punching. Save one note as a reference, and the other as the one to move around the other 87 notes. Press down on the its hammer is into drop (yes, you'll need enough drop to see this), and add/remove enough paper punchings so that the pressure required to hit drop is reasonable (YMMV). Remember that the depth and pressure is only that which will get the hammer clear of let-off. Greater pressure and you'll have an AT thinner than your reference punching (and inversely as well).

    Remember this pressure and duplicate it on the other 87 notes. And it does get hairy doing the sharps whose FRPs hiding 2.5" underneath the white keysticks. But given minute inconsistencies of leverage throughout the parts, even keydip will never equal even AT. And if a pair of adjacent white keys differ by 15mils, a pianist will always notice that 15mil difference in the AT and not the dip. 15mils is 33% of a 45mil AT, but 4% of 3/8" dip.

    I first heard of this from a Yamaha class by LaRoy Edwards 40 years ago, and not long after from the late Bill Garlick during his time at Stwy. I never went back to constant dip after that.

    ------------------------------
    William Ballard RPT
    WBPS
    Saxtons River VT
    802-869-9107

    "Our lives contain a thousand springs
    and dies if one be gone
    Strange that a harp of a thousand strings
    should keep in tune so long."
    ...........Dr. Watts, "The Continental Harmony,1774
    +++++++++++++++++++++
    ------------------------------



  • 64.  RE: Letoff/Drop regulation

    Posted 03-28-2022 14:31
    All good thoughts, and yes a cautionary note in trying to achieve a super sensitive close to the string let off in a home piano with worn parts can very quickly lead to hammer blocking etc., for concert instruments or your own piano try the 'sound off' procedure ,  press sustain pedal, then play note gently multiple times and adjust let off  until you hear  hammer graze the string , for clearer definition temporarily lower the drop screw.
    www.snowpianos.com

    ------------------------------
    Martin Snow
    South Burlington VT
    617-543-1030
    ------------------------------



  • 65.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 03-28-2022 19:03
     >>for concert instruments or your own piano try the 'sound off' procedure ,  press sustain pedal, then play note gently multiple times and adjust let off  until you hear  hammer graze the string ,<<

    Greetings, 
       This approach is best in the top octaves of the piano, as the distance a bass string will travel is far greater than one in the top octave or two. Even so, a let-off that actually touches the string will often affect the voicing. Action compliance can let the hammer, on a hard blow, go beyond the let-off that occurs on very soft playing.   If let-off is set close enough to graze a lightly struck bass string, the hammer is going to collide with that string on a repeated hard note. The excursion zone on a long bass string  reaches below the point of let-off and the string can meet the hammer on its (still powered) way up. Results I have seen are repetition failure, complaints of impact sensations,  and/or broken strings.   

       I use the sostenuto to hold the damper out of the way, give the note two quick, staccato,  FF blows. Then, as quickly as possible, play the hammer just through escapement.  When the hammer  just lightly grazes the string doing it this way, I then back the button just enough so that it doesn't. This insures that the jack will be free of the knuckle any time the string and hammer are in contact.  This is the let-off setting I use before I set key-dip by aftertouch, and coupled with a consistent aftertouch, pianist always comment on control.... 

      Caveat: If considerable string leveling is done after this, the let-off needs to be reset or checked, as it is a sensitive consistency this approach creates. 
    Regards, 





  • 66.  RE: Letoff/Drop regulation

    Posted 03-29-2022 14:51
    Ed, greetings too, and yes as I was writing that post i was remembering the issues you mentioned in paragraph 1, and I also used the sound off  method  primarily in upper octaves hmmm maybe dear Bill Garlick  suggested this procedure either while at NBSS or later  when I spent the week with him at the Steinway factory …all best.  Martin.
    www.snowpianos.com

    ------------------------------
    Martin Snow
    South Burlington VT
    617-543-1030
    ------------------------------



  • 67.  RE: Letoff/Drop regulation

    Member
    Posted 03-28-2022 19:23

    If one checks for consistent amount of hammer rise after letoff, then that seems to me to be a good indication of consistent AT.

    Yes, I've noticed a problem with checking if drop is too high. On the Kawai (with S-E) I was able to achieve checking by quickly rough-sanding the hammer tails. The budget didn't allow huge attention to this.

    I will say this: I can certainly notice the difference in feel with simultaneous escapement. (My assumption is that this is done during regulation and isn't a stand-along procedure, and presupposes a well-lubricated action.) As I believe someone already mentioned, with simultaneous escapement the repetition lever is helping to hold the hammer up, so the jack isn't scraping against full friction, just by itself on the knuckle. Which gets me to thinking that the repetition lever might need to be set up just barely higher than "standard regulation" on hammers with somewhat worn knuckles.  And if it is, does that matter so much in terms of somewhat worn, imperfect actions? So long as the thing plays and fast repetition can be achieved?

    Anyhow, although not a great pianist,  I always play the thing after I regulate and if I don't find any problems and I want to keep playing, then I call it good. This is the acid test. I can play fast; not good, but fast. And I do like the feel of simultaneous escapement and my thought is to achieve this, and then workaround other problems with sub-optimal actions. Maybe not a great thought, but there it is.

    I've noticed, as many others have expressed, that regulation isn't hard-and-fast "37 steps," which are just a starting point for understanding what's going on.



    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 68.  RE: Letoff/Drop regulation

    Member
    Posted 03-29-2022 13:15
    Correction and observations:

    I just finished setting simultaneous escapement on a Steinway D, from F3--B4, as an experiment that the customer and I agreed to (no charge.)  I'd previously regulated this piano. The customer agreed this was an improvement to the touch and I'll be doing the rest of the keys. The change in touch is: a lighter touch due to mitigation of friction from jack escaping knuckle (repetition lever is helping to hold hammer up as jack escapes) and ability to play softer more easily. Also, of course there's no longer a bump when the hammer goes from let-off to drop.

    Checking has nothing to do with drop height regarding s-e; I must have confused problems with checking on another piano.

    Regarding AT and repetition lever strength, yes, AT has to be pretty minimal to prevent blocking of strings/bobbling. But it's also my observation that the repetition spring has to be set to "just barely doing its job" or else there will be bobbling.  So the repetition lever has to be able to push the hammer up (hammer-to-checking test) but it can't spring the hammer into the strings on soft blows.


    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 69.  RE: Letoff/Drop regulation

    Member
    Posted 04-12-2022 08:29
    More corrections:

    Jim said, "The other problem with super high drop, is it will kill checking dead." Of course this is right. But I wonder how much this matters since the hammer is being held up by the repetition lever? A new way of looking at repetition?

    This corrects what I said above: "Checking has nothing to do with drop height regarding s-e." Just me being confused as I had forgotten what'd been said about high drop and checking; I then re-read this thread.



    ------------------------------
    Don Dalton
    Chester VT
    ------------------------------



  • 70.  RE: Letoff/Drop regulation

    Registered Piano Technician
    Posted 04-12-2022 11:48
    >>Regarding AT and repetition lever strength, yes, AT has to be pretty minimal to prevent blocking of strings/bobbling. But it's also my observation that the repetition spring has to be set to "just barely doing its job" or else there will be bobbling.  So the repetition lever has to be able to push the hammer up (hammer-to-checking test) but it can't spring the hammer into the strings on soft blows.<<

    Greetings,
       The "job" of the repetition spring is to accelerate the key's return upon release from checking. It is not to lift the hammer. We set the spring by the speed of the hammer's lift, but if we observe the hammer during fast repetition, we see that the jack is allowed under the knuckle before the hammer rises from its checking position. 
       The speed of the key's rise varies little between a spring that will throw the hammer off the knuckle and a spring that will lift the hammer just fast enough to feel the slightest 'kick' in the key.  
    I have the best touch when I have drop set at the same distance as let-off and the spring just from enough to feel but not enough to propel the hammer into the strings. 
    Regards, 
    Ed Foote