[pianotech] Fixing flexy stage dolly

[Mark Schecter]

Hi, Susan.

Thanks for describing this solution. It sounds very crafty, and like it 
would work well, if somebody knew how. I'm trying to work around their 
not knowing how, as I mentioned in a different branch of this thread. We 
can't even get people to water the Damppchasers. I guess their minds are 
elsewhere, wherever that is. As Norman mentions just after your post, 
turning the wheels across each other solves the brakeless issue, and the 
jack-post seems to solve the jiggles, so maybe that combination will do 
the trick. I'll report back when it's in. Thanks again.

~Mark

On 1/28/13 6:27 PM, Susan Kline wrote:
> 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
>>