[pianotech] Fixing flexy stage dolly

[Susan Kline]

I dealt with a similar problem in a much more shirtsleeves manner.

The big wheels on a Baldwin SD-10 truck, rendered non-round by too many
years of jamming across thresholds, had been replaced with whatever 
could be
found in the coastal town where it lives. They were balky, too big, and
squishy, the brakes didn't work, and the piano would "walk" during playing,
(as well as shimmying like my sister Kate) plus the piano was very hard
to roll around, totally having a mind of its own -- a very heavy mind.
Well, it still does. <sigh> Plus the lady teachers doing far too much of
the moving are getting old and some of them frail.

What I did was to put a piece of card next to each square cup holding a 
leg and scribe
a line to record the height and angle of the cup, which was not parallel 
to the
stage floor. Then I took scraps of pinblock material, cut them into 
wedges at
the appropriate heights and angles, and covered the two long sides with 
thick
shoe leather, glued on with a thick layer of carpneter's glue. Trimmed 
flush,
it looked neat enough. I made them long enough to have some length on 
both the low
and high sides of the cups in use, so they were easy to kick back out 
again.

I also scribed the name ("right", "left" and "tail") into the wood with
a dremel tool, then painted the wood flat black. I added
a small rubber mallet to the getup, and I put the hooked side of velcro
tape onto the truck struts near each cup, with the fluffy tapes on the 
wedges,
on the side without writing.

The players would position the piano (with a lot of effort), then kick
the wedges under the leg cups, maybe pounding with the rubber mallet.

They would also shred the leather by ignoring the placement of the screws
protruding through the cups, despite my beautiful ink drawing showing
them how to miss them, and they'd almost always trade the wedges
around, so that they got used on the legs where they didn't fit -- the
heights and angles were different for all three. Sometimes the wedges
would walk to strange places because they didn't notice the velcro waiting
for them. Just slap the wedge onto its velcro on the truck, ready for
the next use. It seemed simple enough to me ...

Year after year, I would trade them back, glue down the shredded leather,
find the missing mallet, etc.

Of course, I should just have bought them the right wheels, which I finally
did, only to have them ignored instead of installed.

I must say that the wedge idea works just fine to stabilize the piano, and
probably even improves the acoustics by putting something solid between
the floor and the legs. And they are easy enough to make.

It would have been easier if the screws into the bottom of the legs hadn't
been protruding beneath the cups. The wedges still had plenty of room to
do their job if inserted along the edges of the square cups, but people
wouldn't notice that.

Still, they more or less worked for many years, and they didn't look bad,
and they certainly were inexpensive. The piano was very stable with them
in, solid as a rock, and they were easy to kick back out again afterwards.

Susan Kline
(Newport Arts Center)

Mark Schecter wrote:
> Hi, all.
>
> I take care of a Steinway D at a local school which rides on a stage 
> dolly. Yesterday I tuned for a pianist who found the movement of the 
> piano under heavy playing to be disturbing. When he would play big 
> octaves in both hands, the piano shook in a way he could feel through 
> the keyboard. As Jurgen mentioned recently, the arms of the dolly are 
> like big leaf springs. I have an idea to improve this for which I'd 
> like to get your feedback.
>
> Because the piano legs rest on the ends of the dolly arms, outboard of 
> the wheel location, the wheels act as fulcrums, and the weight of the 
> piano lifts the central arm-connecting part of the dolly. If you press 
> down on the rim of the piano, the center of the dolly rises toward the 
> main rim braces. I am thinking if I put a vertical post between the 
> dolly and a main rim brace, it will greatly reduce the dolly's freedom 
> to move, thus less flexible. I would make it long enough to be in 
> compression, rising from the central arm connecting plates of the 
> dolly, upward toward the underside of the brace, and wedged between 
> the two.
>
> Has anybody tried this? What were the results or problems? Do you have 
> any suggestions for improvements to this idea? Thanks very much!
>
> ~Mark Schecter
>
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