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Steinway Damper Guide Rail - when to rebush?

  • 1.  Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 10 days ago
    Hello Pianotech friends,

    In the past, I have been fairly tolerant of damper guide rail bushings if I'm replacing damper felt. On the few jobs I've done, the guide rail felts have looked pretty good. My understanding is that Steinway guide rail bushings are purposefully a little loose with the concept being that the wire will gently ride along one side of the bushing for stability.

    "To rebush or NOT rebush. THAT is the question".

    For those of you with more experience with grand damper replacement, how do you decide when to replace the felt?

    My concern is that rebushing will not only cost the client a few more hundred dollars for the  job, but also create a lot more wire bending for me when reinstalling the dampers. If the whole damper system is being replaced it makes sense to rebush the rail, but what about just a basic damper felt replacement?

    Thanks, as always!

    ------------------------------
    Ryan Sowers - Puget Sound Chapter #985
    Olympia WA
    360-705-4160
    ------------------------------


  • 2.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 10 days ago

    Rebush. Drill out the originals (3/16" bit, I believe, but check first) and lightly chamfer the empty holes top & bottom. Cut (or rather, tear) a dozen or so short pies of bushing cloth of the correct width. Clamp the rail to the bench and run all the strips through and cut them all at once. This goes pretty quickly. Do NOT use any glue – the chamfering will hold the cloth in place quite securely. After all the holes are bushed insert #7 bridge pins and size overnight with your favorite sizing agent (I use isopropyl alcohol, but profelt also works fine). This typically leaves the bushing ready to go, with no further easing required.

     

     






  • 3.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 10 days ago
    Only relatively recently did I realize how really efficient damping completely redefines the experience of playing a piano. My damping was okay previously, but really efficient damping, timed really well, is such a game changer, from the pianist's point of view, that with my greatly improved damping work, I went back and redid my own piano to the same level of efficiency. The slop I was fixing was not in the damper guide rail bushings , but in other aspects of the felt seating. but loose damper guide rails (edit) would not have allowed the other felt fitting work.

    So, dampers that are not adequately restrained in the damper guide rail, will challenge damping efficiency from the word go. I would rebush if they are loose, as per David Hughes' recommendations, and it sounds like Mark's above.

    On the other hand, if they just play christmas carols once a year,,,maybe not bother. It depends on your customer. If they are a decent pianist, and you manage to give them real efficient damper fitting and timing, they will be surprised and very appreciative, even if, previously, they did not know what they were missing.  So, while my answer is yes, it also depends on the customer.

    (edited as per Karl's post below)

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



  • 4.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 9 days ago
    How do you orient the seams, Mark?

    Bob Anderson
    Tucson, AZ




  • 5.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 10 days ago
    Mr. Ialeggio,
    Are you saying that the damper block bushing (where the damper block attaches to the underlever) is more important than the guide rail for efficient damping? My experience is that the block/underlever bushing being too tight is a frequent cause of damper failure. A guide rail bushing that is loose enough to allow the wire to rattle will definitely make good damping harder.

    ------------------------------
    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 6.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 9 days ago
    Thanks for this Jim - I totally agree.

    I went to a state music teacher conference a few years ago and the key note speaker, a concert pianist, talked about how half his practice time was spent focused on pedaling. Hearing that really changed not only my own playing, but my technical work as well.

    It's always hard to know where to try the line with client's pianos. Each situation has a unique cost/benefit ratio. My own model O is from 1912 and still has all its original parts, and while I've been meaning to get around to rebuilding the action, honestly it still plays very nice and it's easy to put it off.

    My general hesitation to rebushing the guide rail was wondering if changing the felt would actually make more work when it came to reinstalling the dampers. If the dampers are nicely aligned before rebushing the rail, do you find rebushing the rail results in more wire bending? Damper wire bending can be so subtle and nuanced that a .5 mm of adjustment seems significant.

    Since the general concept of Steinway is that the wire is only touching the bushing on one side of the hole, I wonder what improvement, if any, would replacing the felt provide if it appears to be in good condition.

    What I'm thinking is an experiment with my own piano: replace the felt with original guide rail bushings and see how it performs, and then rebush the rail and see what difference it actually makes. I wouldn't want to do this on a client's piano, but it would be an interesting experience to try it on my own and report back.

    ------------------------------
    Ryan Sowers
    Olympia WA
    360-705-4160
    ------------------------------



  • 7.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 10 days ago
    OOPs...wrong term. You are correct, I meant to say damper guide rail bushing...thanks for the correction...I will edit my post..

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



  • 8.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 9 days ago
    If you tear the cloth accurately, there are no seams <g>

    Seriously though, Steinway recommends that bass damper wires bear "slightly" towards the treble and treble wires "slightly" to the bass, so I put the seams fore & aft.

    Ryan -

    I'd think that just replacing the damper felts would entail some remedial wire bending, and I'd rather have polished wires rubbing against clean, well sized cloth. It's the little things like this that add up to a better experience for the pianist. Removal, de-bushing, cleaning, rebushing and reinstalling typically only take an hour or so, once the dampers are out.

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



  • 9.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 8 days ago
    I don't lean the wire against the side of the bushing. Why induce friction? The new felt is glued on (hot hide) and allowed the dry prior to fitting the set.

    I hold a small square against the guide rail and wire to have the wire perpendicular thru the hole. Then I center the head over the unison.
    With the wire still secured to the square, I have the wire entering the top flange such that there is not twisting to the underlever.
    The dampers travel straight up and down.  Ed Foote's Wire Wizard makes bending a cinch, thanks Ed !

    To make wire insertion into the top flange easier, ream the hole around 5 thousandths larger than the diameter of the wire.
    Cloth that is properly sized will not leave a seam as such. But I do place the 'break' at either the front or back since the damper head will be
    weighing on the wire towards the offset. On double-bushings I place the breaks opposite each other.

    PS:  Always rebush the guide rail. It will be quieter and support the wire better.
    ------------------------------
    Regards,

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



  • 10.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 8 days ago
    Thanks for all the helpful feedback folks! Much appreciated.

    I'm fascinated by Ed Foot's "Wire Wizard"! I searched the archives and found a video link. Holy cow, what a creation! I'm emailing him today to see if he will make me one.

    Cheers!

    ------------------------------
    Ryan Sowers
    Olympia WA
    360-705-4160
    ------------------------------



  • 11.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 8 days ago
    The idea is to just have it *barely* leaning against the bushing. This creates stability of the damper head and helps keep the wire from vibrating. Here's a clip from Mario Igrec's "Pianos Inside Out": http://www.pianosinsideout.com/regbig.pdf

    To Center the Wire in the Bushing or Not?

    If the damper wire bears against the bushing with significant force,
    the bushing will wear out prematurely. The logical conclusion is to
    adjust the wire to be centered perfectly in the bushing. However,
    the damper is actually more effective if the wire is slightly off center.

    Here's why.

    Let's look at a single bass string. Although the hammer excites
    the string to vibrate in a vertical plane, the vibrations change direction, and soon the string is vibrating in all directions. When the
    damper falls on the string, it pushes the string down, causing the
    vertical vibrations to quickly subside. Vibrations around the horizontal plane, however, cause the damper head to move left-right.
    You can observe this when loudly playing low-bass notes-the
    damper head flutters horizontally (side to side) when it touches the
    string. By itself, the damper can't stop horizontal vibrations-that's
    the job of the damper bushing.

    The bushing damps horizontal excursions of the string by limiting side-to-side travel of the damper head. The tighter the bushing,
    the more effective it is. However, the adjustment of the damper
    wire can make the bushing even more effective. Suppose that the
    string is deflected from its rest position by 1 mm to the left and
    1 mm to the right.

    Also suppose that the damper wire is 1 mm
    thick and the opening in the bushing has a diameter of 3 mm, leaving 1 mm of room on each side of the wire. If the damper wire is in
    the middle of the bushing, the string will move it equally in both
    directions, for a total motion of 2 mm. But if the wire leans against,
    say, the right side of the bushing, the excursion to the right will
    cause almost no damper movement, whereas the excursion to the
    left will bring the wire to only the middle of the hole. The total
    motion will be only 1 mm, half of what it would be with the wire
    centered. The degree of the lean must be very gentle or the added
    friction will offset the benefits of this technique by making the
    damper less effective in the vertical plane.

    The lean also makes damper movement, when lifted with the
    pedal, appear more precise because there is no fore/aft movement
    of the damper heads

    ------------------------------
    Ryan Sowers
    Olympia WA
    360-705-4160
    ------------------------------



  • 12.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 8 days ago
    Enjoying this thread.

    Ryan, can you post a link to that video with Ed Foote's wire wizard?

    Thanks!
    Daniel

    ------------------------------
    Daniel Achten
    Chattanooga TN
    423-760-2458
    ------------------------------



  • 13.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 8 days ago
    Good idea Daniel,
    Here the video of "Ed Foote's Wire Wizard"
    Private Video on Vimeo
    Password: Foote

    ------------------------------
    Ryan Sowers
    Olympia WA
    360-705-4160
    ------------------------------



  • 14.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 8 days ago
    I'm not sure if Ed has a production setup. Until that happens, I doubt that they are available.

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

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



  • 15.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 8 days ago
    This is based on an earlier version used in the M&H factory (probably pre-WW2), which the late Paul Monachinno would show in his classes for the new H&H Co. in the early '90s. Paul started out at the M&H division in Rochester NY in the '50s, and got to know many of the old timers.There's enough in this video for a talented woodworker to make their own. (No, don't look at me <G>)

    ------------------------------
    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: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 7 days ago
    I just heard back from him - and he said he's willing to send me his to copy. I'm going to reach out to Mark Purney at Supply88 and see if he can 3D print them - it seems up his ally!

    ------------------------------
    Ryan Sowers
    Olympia WA
    360-705-4160
    ------------------------------



  • 17.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 8 days ago
    After Ed's video, watch Jason Kanter play Ravel's Pavane.

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

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



  • 18.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 3 days ago
    Ryan Sowers went:
    "I'm going to reach out to Mark Purney at Supply88 and see if he can 3D print them - it seems up his alley"!

    I'd love one, when they hit the market.


    ------------------------------
    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
    +++++++++++++++++++++
    ------------------------------



  • 19.  RE: Steinway Damper Guide Rail - when to rebush?

    Registered Piano Technician
    Posted 3 days ago
    I'd love one too.
    Daniel

    ------------------------------
    Daniel Achten
    Chattanooga TN
    423-760-2458
    ------------------------------



  • 20.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 3 days ago
    Maybe Dale can add it to his production line.

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

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



  • 21.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 2 days ago
    I made this last year, after seeing Ed's tool. As you can see, its quite different than his tool, and only tries to do the one part of the process. It addresses the top two bends, which I used to find the most difficult to adjust, when installing a full set of dampers. With this, and a number of other process changes, my damper work took a quantum leap.

    I find the top two bends, which I do first,  define the precision of the installation, speeds the lower two bends, and give one a linear process, which allows you to diagnose problems quickly. That is, if you prove top bends have centered the felt on the strings, and left the wire traveling vertically and parallel to the side of the head, and plumb, you know the top side is correct. Since you have now proved and eliminated those variables, you  can focus diagnostics on the lower two bends. it makes for efficient diagnosing, mostly, in my procedure, fingering incorrect lower bends.

    The problem I used to find, was that as I manipulated those top two bends, ie, as I manipulated them to center the felt on the strings, and have the wire traveling plumb through the guide rail, I had no gauge to tell me exactly how much I had actually moved the wire. Final moves can be quite small. However, without a gauge, I was not able to make the small moves with precision. And, I also was almost positive, that my bends were undoing each other, wasting huge amounts of time. So:

    1- I needed a gauge to tell me how far I actually moved the the bends. Bends can be mushy. You tweak the bend, but you really don't know how much you actually moved it. One needs an index, to compare before and after bend wire position. Also, the second bend often undoes the first bend, because the wire moves a tiny bit in the head, or some other mushy interface. I knew this mushyness was happening, but had no way to gauge the actual move I made in the wire...so a gauge was needed to compare before and after bend position of the wire.

    2- Side of the damper head needs to be vertical and parallel to the travel of the wire as it goes through the guide block, and all of them plumb. I needed a gauge to tell me the bends left the wire going through the guide rail dead nuts parallel to the side of the head...instead of guessing...and guessing wrong.

    So this tool is on a piece of plywood that sits on the keybed, quite securely...no clamps needed.

    The tool clamps the head repeat-ably parallel to the gauge lines, in a single, quick motion...of an eighth of a turn of the knurled screw. You massage both top bends with the damper clamped in the tool, until gauge lines and wire are parallel at the guide rail location of the wire, and have moved a given amount between the several gauge lines. SInce the damper clamp sits securely on the keybed, no hands are needed to stabilize the clamp, and two tools are used, one in each hand, to adjust the top bends in one move. Two tools reduces the mushy-ness of the adjustment. Gauge lines tell the whole top-two bends story, very quickly. Quickly remove the damper from the clamp, test in the piano, and return to the clamp for large or tiny adjustments...but the gauge lines, and the repeatable clamping accuracy, ie head parallel to the gauge lines, are the thing that makes this tool work for me.




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



  • 22.  RE: Steinway Damper Guide Rail - when to rebush?

    Member
    Posted 2 days ago
    My gage for adjusting the top two bends is the damper wire bending tool itself. I hold the shank tightly to the head and sight along on its length. I judge how much it should move by sighting along the 'shadow' on the curve or the shank.

    There are two score marks along the shank where I would index the wire bending pliers to make the bottom bends which are not used now that I have Ed's Wire Wizard.

    A small square held against the belly rail and damper guide rail insures the wire's perpendicular travel thru the bushing.

    It's really great how everyone develops their own style of performing the same task.

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

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