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  • 1.  How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-22-2022 11:14
      |   view attached
    Greetings all,
    Occasionally I come to a piano that has letoff screws like the one pictured below (a 1929 Knabe concert grand). Many designs have clearance above the screws, or set them at an angle, but not here. None of my tools will fit from above--how do you deal with situations like this? So far, the only way I've found is to use a long, thin letoff tool, but turning the screws that way is painfully slow. And if they're at just the wrong angle (which they usually are), there's no way to get the tool in. Especially at the end of a section.

    Any ideas?

    thanks!
    Scott

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    Scott Cole, RPT
    rvpianotuner.com
    Talent, OR
    (541-601-9033
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  • 2.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-22-2022 11:36
    I have used a Hart spring tool, or a stiff wire bent at nearly 90 degrees about 3-4 mm from the end. I also have a couple home made capstan wrenches (nail in the end of a dowel of different diameters) that work fairly well for the purpose.

    If I need to do a lot of turning, and it is pretty consistent (a full turn up, for instance), I'll remove the rail, do that turning wholesale, then put it back and touch up.
    Regards,
    Fred Sturm
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda






  • 3.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-22-2022 11:40
    I have also used the end of a capstan tool, it the tip is thin enough to fit. The choice of straight and angled ends has always let me access the eye so that I can turn it no matter what position it starts in.

    Kathy




  • 4.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-22-2022 13:27
    There is a pair of pliers sold with jaws curved to be able to grasp a round let-off dowel. These can also be used to turn capstans. I have not tried those pliers on this kind of screw eye let-off arrangement, but if you happen to have a pair, it would be worth a shot.

    Alan

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    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
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  • 5.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-23-2022 10:52
    Hi Alan,
    Yes, got those pliers. Sometimes they fit, sometimes they don't…
    Scott

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    Scott Cole, RPT
    rvpianotuner.com
    Talent, OR
    (541-601-9033
    ------------------------------



  • 6.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-22-2022 16:20
      |   view attached
    These very sharp needle nose pliers are my go-to tool for eye type let off buttons. When the jaws are closed they slip right into the eye. When the angle is wrong for that you grasp the eye with the jaws. They are short enough to have enough range of motion.

    Your bigger problem seems to be that you need to raise that let off rail. It's not clear to me from the picture how you do that.

    Ted Kidwell, RPT, CTE
    Kidwell Piano Works
    916 200 8747





  • 7.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-23-2022 07:26
    As Ted noted, the rail itself needs to be raised so that you have room to adjust the let- off buttons, which are already about as high as they can go. I believe the mounting brackets for these actions are screwed into bottom of hammer rail. You may need to remove action from keyboard, remove the sections of let off buttons and screw the bracket into the hammer rail one full turn. The question in my mind is why a nearly 100 year old piano would need such an adjustment. It looks to me like the capstan screws are also really low. Seems like the action isn’t at the right height, which might lead to all sorts of action regulation issues.

    David Graham
    Graham Piano Service, Inc.
    512 S. Main St.
    Sycamore IL 60178
    815-353-5450
    grahampiano1@yahoo.com




  • 8.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-23-2022 11:22
    I don't see how raising the letoff rail would help anything. It is the space between the tops of the screws and the bottom of the hammer rail that is the problem. That space would remain the same wherever the letoff rail were placed vertically. It would be possible to machine (chisel/plane) material from the front bottom of the hammer rail to gain more access. 

    Bottom line, a very stupid design, unfortunately quite common with Knabes and Chickerings (perhaps others) of the era. One wonders what they were thinking. It must have been troublesome enough to do the original regulation in the factory.
    Regards,
    Fred Sturm
    "The cure for boredom is curiosity, and there is no cure for curiosity." Dorothy Parker






  • 9.  RE: How do you deal with these letoff screws?

    Posted 01-23-2022 09:18
    I have two horizontal letoff tools, but I’m not sure that even the thinnest would work on this action as they are turned all the way up.
    One I purchased from either Schaff or Pianotech and has a straight pin letoff tool on one end and a shallow cup of the other for this type
    of letoff screw. It is pretty thin, but… The other is a small ratchet handle from a mini socket kit, the kind with a few mini sockets and a screwdriver
    tip. Turns out it fits great on a Steinway letoff rail. The nice part is that once you get it on there you can turn it as much as you need to without
    removing the tool.

    Jeff Cutler
    University of Wisconsin
    Eau Claire




  • 10.  RE: How do you deal with these letoff screws?

    Registered Piano Technician
    Posted 01-23-2022 19:46
    Punchings are too thick, replaced I would guess. Hammers are worn-out?
    Replace punchings, move let-off rail out 1-2 mm , make sure eye screws are deep as possible in wood button.
    The pictures indicate multiple issues are possible.
    All the best!

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    Mark Adams
    Artist Piano
    Solana Beach CA
    858-583-3333
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