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bowing of grand piano truck

  • 1.  bowing of grand piano truck

    Registered Piano Technician
    Posted 07-14-2015 07:01

    I recently visited a Steinway B that I sold to a concert venue back in '07. At that time I had installed the piano on a truck. Apparently over time the truck's central hub has bowed up, resulting in a lowering of the three arms and reduced height of the pedals and keyboard to the point that it's quite noticeable to pianists. I tried tightening the bolts at the hub, but they were already as tight as possible. The arms are at or near their minimum extension. Is this flexing over time a common problem, and more importantly, is it correctable?

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    Mark Dierauf
    Concord NH
    603-225-4652
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  • 2.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 07-14-2015 08:45

    Mark 

    The least likely scenario is that the steel itself is flexing.  Apart from not knowing the manufacture of this truck, the first thing, other than the tightness of the bolts, would be to look at the welds on the 'bolt' arm.  It's possible that. at some point, perhaps if bolts had been loose, one or more welds might have failed.    You said you tightened the bolts at the hub, but didn't mention the 'arm' bolts.  All are best tightened with the weight of the piano removed or at least relieved (blocks under feet). 

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    David Skolnik
    Hastings-on-Hudson NY
    914-231-7565
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    Original Message


  • 3.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 07-14-2015 09:34


    Hi Mark-

    We had this problem with almost all of the old trucks on larger pianos on campus here until they were replaced.  The Physical plant had cut 4'x4' studs to go between the center plates and the under beam to hold the plates down level.  It looked bad but solved the problem as far as they were concerned.  What brand of truck was used?  I don't think you will have this problem with the Colson trucks from Jansen.  

    good luck,

    Dennis. 
    ------------------------------
    Dennis Johnson, R.P.T.
    St. Olaf College
    Music Dept.
    Northfield, MN 55337
    sta2ned@stolaf.edu
    (507) 786-3587
    ------------------------------


    Original Message


  • 4.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 07-14-2015 14:18

    Mark,

    This is often the result of tightening the bolts while the truck is supporting the weight of the piano. It starts out slightly bowed and gets worse over time. I suggest jacking up the piano at each leg until you can put a block of wood underneath, lifting the truck wheels off the floor. What I like to do then is to take a Quick-Clamp and reverse the removable jaw so that it becomes a spreader rather than a clamp. I place it between the bottom of the piano, at a beam, and the center plate of the truck. Loosen the plate bolts slightly, use the clamp to create downward pressure on the plate until it is bowed very slightly downward rather than up. Then re-tighten the plate bolts. When you remove the blocks and the tires are back on the floor, the bow should be gone.



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    Craig Miller
    Marietta GA
    770-321-9390
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    Original Message


  • 5.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 07-16-2015 12:50

    This is what I used when I needed to replace the casters and adjust the length of the arms of the truck.  In this case bowing was being caused by the length of one arm being much longer than the other two. With the weight of the piano on the blocks and all of the casters off the ground you can loosen all the bolts, reset the arms lengths with the help of a rubber mallet, and replace the casters.

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    Robert Callaghan
    Reno NV
    775-287-2140
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    Original Message


  • 6.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 07-15-2015 23:40
    Not uncommon, but there are some more steps you might take.  I'm sure someone will have good reasons not to do any of this, but here are a couple ideas.

    First I would put something (like hardwood blocks) under each arm at the leg lifting each with a jack-in-the box or some other means by a slight amount (just less than lifting the wheels off the floor) then loosen the bolts.  See if the bow remains.  If it drops shift the hub enough to grab some new spots in the arms then retighten.  See if that does it.  

    If the bow doesn't drop after loosening all the screws there may be permanent bend in the arms.  Check them with a straightedge.  In that case, if there's not a humidity system installed, you could consider putting a hardwood block across the posts and a 4x4 or pipe down to the hub so the weight of the piano is pushing down on the hub. 

    Beyond that, I have a good spider dolly I can sell you that we don't need. :-)

    ------------------------------
    Gary Bruce, RPT
    Bruce Piano Service
    Edmond, OK
    405-413-TUNE
    www.brucepiano.com
    Gary Bruce
    Registered Piano Technician
    405-285-8324
    BruceMusicStore.com

    We would love for you to connect with us!



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  • 7.  RE: bowing of grand piano truck

    Posted 08-01-2015 14:42
      |   view attached

    This thread brings up one more of the numerous problems and disadvantages of stage trucks. I am surprised they are still sold in such quantities.  In Europe these "spider dollies" are largely unknown, and recital spaces and institutions have their pianos on proper casters which work well, cause fewer problems while avoiding the "warehouse" look.

    http://www.pianofortesupply.com/parts/casters/grand-casters/grand-casters-2/


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    Jurgen Goering
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  • 8.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 08-01-2015 22:28

    Jurgen,

    If you worked in a “blue-collar” university setting, you wouldn’t be asking such a question. I have maybe ten grands (including concert grands) that are moved constantly, and the movers are whoever needs to move them (students, faculty, guests), as we have a skeleton staff that can’t be there all the time supervising and baby-sitting. I don’t have the budget, the time, the patience, nor the inclination to be repairing and replacing legs and lyres on a several-a-year basis. So that’s why there is such a market for spider dollies. (And for upright dollies as well - after you have had a couple uprights pushed over onto their backs, you begin to appreciate those also, not to mention liability concerns).
     
    Large casters are wonderful for concert venues, and places where the moving of a piano is forbidden to anyone but those authorized. That is certainly not the case at my university, and I am sure it is the same at a majority of others, so I bless the manufacturers and sellers of spider dollies. They make it possible for us to function.



    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------


    Original Message


  • 9.  RE: bowing of grand piano truck

    Posted 08-02-2015 01:24
    Hi, Jurgen, Fred,

    I'm definitely with Fred on this.

    Even in a couple of fairly well-funded places with which I'm familiar,
    no one seems to think much of just pushing a piano around, especially if
    it's "in the way". In many cases, the faculty are the worst offenders.

    While there's no question in my mind but that the use of spider dollies
    negatively affects the tone of the piano, just the liability issues
    alone, should a leg break and injure anyone, should be enough to err on
    the side of caution/prudence. (...come to think of it, "Prudence" isn't
    a bad name for a piano dolly...).

    Kind regards.

    Horace



    On 8/1/2015 7:27 PM, Fred Sturm via Piano Technicians Guild wrote:
    > Please do not forward this message due to Auto Login.
    >
    >
    > Jurgen,
    >
    > If you worked in a blue-collar university setting, you wouldnt be asking such a question. I have maybe ten grands (including concert grands) that are moved constantly, and the movers are whoever needs to move them (students, faculty, guests), as we have a skeleton staff that cant be there all the time supervising and baby-sitting. I dont have the budget, the time, the patience, nor the inclination to be repairing and replacing legs and lyres on a several-a-year basis. So thats why there is such a market for spider dollies. (And for upright dollies as well - after you have had a couple uprights pushed over onto their backs, you begin to appreciate those also, not to mention liability concerns).
    >
    > Large casters are wonderful for concert venues, and places where the moving of a piano is forbidden to anyone but those authorized. That is certainly not the case at my university, and I am sure it is the same at a majority of others, so I bless the manufacturers and sellers of spider dollies. They make it possible for us to function.
    >
    >
    >
    > ------------------------------
    > Fred Sturm
    > University of New Mexico
    > fssturm@unm.edu
    > http://fredsturm.net
    > http://www.artoftuning.com
    > "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    > ------------------------------
    >
    > -------------------------------------------
    > Original Message:
    > Sent: 08-01-2015 14:42
    > From: Jurgen Goering
    > Subject: bowing of grand piano truck
    >
    >
    >
    >
    > This thread brings up one more of the numerous problems and disadvantages of stage trucks. I am surprised they are still sold in such quantities. In Europe these "spider dollies" are largely unknown, and recital spaces and institutions have their pianos on proper casters which work well, cause fewer problems while avoiding the "warehouse" look.
    >
    >
    > http://www.pianofortesupply.com/parts/casters/grand-casters/grand-casters-2/
    >
    >
    >
    > ------------------------------
    > Jurgen Goering
    > ------------------------------
    >
    >
    > Reply to Sender : http://my.ptg.org/eGroups/PostReply/?GroupId=49&SenderKey=52e9bbfa-5661-48d1-ab4f-5ee362602d4c&MID=651279&MDATE=756%253a45%253d456&UserKey=3feecf45-4a69-4cff-bbb2-fd6c7eaf0569&sKey=KeyRemoved
    >
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    Original Message


  • 10.  RE: bowing of grand piano truck

    Posted 08-03-2015 16:02

    When a member of cleaning staff moved an upright at Sussex University some years ago it fell on top of her foot and she suffered a broken toe. The University maintained she was not supposed to be moving pianos and therefore had no claim for damages. Health & Safety.   Michael  UK

    ------------------------------
    Michael Gamble
    semi retired
    Brighton
    01273813612
    ------------------------------


    Original Message


  • 11.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 08-02-2015 09:17

    The problem with casters -- even the high-quality Euro casters --is that they do nothing to reduce the side forces on the legs.  When you have piano weight approaching a thousand pounds, even a slight irregularity in the floor can at least momentarily immobilize the wheel on that particular leg.  Application of adequate side-pressure to overcome that obstacle can result in broken legs.  Piano legs are built for vertical pressure -- not side pressure.  (Correct procedure is always to lift a leg that is blocked -- see how many stage crews do that).

    The ugly spider trolley causes side pressure to be shared through all three legs and never one leg.  Casters may be fine for venues with immaculately smooth floors, but never in average institutional settings like schools, churches, retirement homes and anywhere there is carpet.  

    The ideal answer is, of course, the transporter with a handle (or strap).  


    ------------------------------
    Keith Akins
    Akins Pianocraft
    Menominee MI
    906-863-7387
    ------------------------------


    Original Message


  • 12.  RE: bowing of grand piano truck

    Posted 08-02-2015 14:29

    Keith:

    Your point is well made.  Pianos in schools do get moved by unauthorized people, and bad things happen.  The brass castors that Jurgen showed roll well and look vastly better on a concert stage.  In addition the sound is better when the piano is connected directly to the floor rather than being isolated by the stage trucks.  I think there is a place for both types, and each should be used for the needs of the venue.  BUT... I have always wondered why some artistic person couldn't come up with a design that would handle the stresses common to stage trucks but look somewhat better than the lift used to raise your car to get the oil changed.  Does that structural strength have to come at such a visual cost?  

    dave

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    David Porritt
    Caddo Mills TX
    903-269-3570
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    Original Message


  • 13.  RE: bowing of grand piano truck

    Posted 08-02-2015 16:14
    All you need is a pneumatic sled system to set the piano on. Hook up the
    air and skate it where you like. Unfortunately, there are thresholds.
    Ron N


    Original Message


  • 14.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 08-02-2015 17:13

    Last time I checked a Grand Transporter was about $1300.  It will move a baby grand or a concert grand and the 8" wheels will almost float over thresholds. It folds up nicely for storage and while it's heavy, it doesn't weigh quite as much as the piano and moves pretty easily.  A grand truck (spider dolly) runs about $500 & up and will move the one grand it's fitted for and has all the negatives that have been previously mentioned plus moving it and storing it are a pain and it may weigh more than some pianos.  ;-)

    I don't get commissions on the Grand Transporter, but I'd sure recommend you get one if you're in a position to do so and have multiple grands to move regularly.  I can pick mine up and put it in my van to take to clients homes when a grand needs to roll across the floor.  The multiple wheel single leg dollies work well, but then you're lifting the piano (6 times) and they are a little tricky over thresholds.

    That's my 2¢.

    ------------------------------
    Gary Bruce, RPT
    Bruce Piano Service
    Edmond, OK
    405-413-TUNE
    www.brucepiano.com
    ------------------------------


    Original Message


  • 15.  RE: bowing of grand piano truck

    Registered Piano Technician
    Posted 08-03-2015 16:55


    ------------------------------
    Clarence Zeches
    Piano Service Enterprise School of Technology
    Toccoa GA
    706-886-4035
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    Original Message