Pianotech

  • 1.  Advice for wobbly Yamaha G1?

    Posted 4 days ago
    We have a Yamaha G1 (70's) that has been great but it's starting to move (mostly side-to-side, but with some front-to-back). On the rear leg, one of the washers can spin a bit and though the front legs don't have that issue, I assume that the fact that it's wobbling means the legs are loosening up and need to be tightened. I have two questions that I need help with, though.

    First, the bolts are square-headed, which seems to have been typical for Yamaha in that period:

    I don't have a square socket, so can't tighten them without gauging up the piano, which it appears some past owner did. Is my best bet to purchase a socket that will fit them and use the existing bolts or, given their age and apparent condition from the picture, see if I can loosen them off and then replace them with new bolts (likely with conventional heads)?

    Second, those bolts hold on the full leg assembly, but it appears that the assembly is made up of an upper portion that gets attached to the body of the piano and then another, longer leg part below that. I can see that the fit between those two parts is not as flush as it should be:

    I expect that this means that my problem may be in how the leg assembly is attached to the piano, or in how the upper and lower components of the leg assembly are attached to each other. If that's the case, is the best course of action just to remove each leg (with a support under that corner of the piano), tighten the mechanism that I assume must be accessible inside the leg once it's removed, and then replace the leg assembly?


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    Darryl Delamont
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  • 2.  RE: Advice for wobbly Yamaha G1?

    Member
    Posted 4 days ago

    When was the piano moved to its current location ? You can tighten up the bolts buy purchasing a large open end wrench or an adjustable "monkey wrench" used fot plumbing fixtures. The threads on the bolt are likely metric and will be hard to match . The rear leg may need a washer and so may the side leg. The best way to do this is purchase a scissor motorcycle jack and use some 4 x 4 pressure treated posts cut into 2 foot sections. You can then safely jack up the piano enough to get the caster clear of the floor. Chances are adding some thin washers will take up the gap space  You may not even need to remove the leg , Before doing anything try tightening the bolts with a proper wrench- that may be all you need to do. You can make a shield out of thin aluminum roof flashing to protect the finish



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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    (843) 325-4357
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  • 3.  RE: Advice for wobbly Yamaha G1?

    Registered Piano Technician
    Posted 4 days ago

    If you have loose washers, make sure the screw hasn't bottomed out, which would prevent it from tightening completely.  Make sure that the proper sized screws were in the proper holes.  Often the lyre screws and leg screws are different lengths, the nose leg screws too.  If the longer ones are in the wrong holes, lots of damage can occur, the action can become jammed, etc.  Loose washers are a red flag, because nobody is going to just leave them loose.
    Having said that, I have seen many legs where the upper plate and the leg are not joined very well, as you can see the gap in your photo.  I've tried filling the gap with epoxy or shims, etc., and not very successfully.  If the joint is loose, you'll need to disassemble it and reglue it, or somehow improve it.  Or just order new legs, which would be the best option.
    Good luck.



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    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
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  • 4.  RE: Advice for wobbly Yamaha G1?

    Registered Piano Technician
    Posted 4 days ago
    You can find a socket which fits the bolt. I think we used SAE not metric socket. Maybe 9/16" or 7/8" size.

    On most of these vintage 1970's pianos, often the rear legs were secured with lag screws, and the
    front legs used machine bolts. Also, the rear leg itself may be taller than the front legs. You'll know when you
    set the piano up and it's tilted. Don't ask me how I know... <g>.

    Beware, as a piano mover found out the hard way....do not use lag screw on front legs!
    It will go up into the cheek blocks and split them!!

    As to the leg separation, this is a failed glue joint. When you take the leg off, you'll see it's joined like the pillars on
    a pedal lyre. Likely a round dowel with a wedge driven into it to secure the lower tapered let with the 'head', or upper
    part of the leg. This will have to be taken apart and reglued.

    Both the bolts not being tight and the glue joint failure have attributed to the 'wobbly' piano.

    Michael





  • 5.  RE: Advice for wobbly Yamaha G1?

    Registered Piano Technician
    Posted 4 days ago
    Hi, Darryl,

    I always carry an adjustable wrench. I never know when I’ll encounter a square nut or bolt. The top plate of the leg assembly is glued to the leg itself. If you remove the leg assembly you’ll see how that works.

    Bob Anderson, RPT
    Tucson, AZ




  • 6.  RE: Advice for wobbly Yamaha G1?

    Posted 3 days ago

    A 12 point socket will fit a square headed bolt. I'm not sure what size socket it is, you'll have to try a socket to find out. 



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    Les Koltvedt
    Marietta GA
    lkpianos@gmail.com
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  • 7.  RE: Advice for wobbly Yamaha G1?

    Member
    Posted 2 days ago
    Sometimes you can turn a socket extension around. Then you have a 3/8 and 1/2 inch square socket
    Use whatever you have to grab the end.