>> The player is mounted on castors which work very well and the
>> adjustment to put the actuators to the key height is quite obvious.
>> But what stops the instrument moving about on its castors when in
>> position?  Obviously something is missing.  Can anyone please supply
>> details of what this is?


While I'm not sure how it was meant to be done on your push-up player,
our Phonola push-up player has a little foot (looks like a whirligig
"top"), mounted on a long machine-screw bolt, that can be turned and
thus either moves the player up under the bottom board to give ground
clearance or down to somewhat affix the instrument in position.

Now, that is a nice idea; however, it turns out that on most flat
surfaces, such as hardwood (or worse: laminated flooring), even _then_
it will still move around.

A trick that we are using now, whenever we take the push-up player for
concerts, are four cups that we place under the coasters by lifting the
player on top of them.  These cups are basically discs with elevated
outside borders -- imagine a street circle surrounded by a curb.  These
discs have felt or other material glued on the underside so that there
is lots of friction, even on a flat surface.  The coasters thus sit
locked in the cups and the cups don't move.

Depending on your player, you will notice that you can adjust the
height of the player by turning the coasters in a same manner as
aforementioned foot.  Hope this helps.

Musically,
greetings by(e) InK - Ingmar Krause
Victoria, BC, Canada
Erlangen, BY, Germany