Ted,  Piano tilters can be quite dangerous if not handled correctly.
The usual scenario is the technician successfully tips the piano on
its back and services or replaces the casters.  He is in the process
of righting the piano with the tilter when the base of the piano slips
off and rolls away from the tilter, and the back of the piano comes
smashing down -- onto the tilter and the surprised technician.  This
occurs when the casters touch down on the floor before the piano is in
an upright & stable position.  The tilter is now no longer in control.

There are two solutions:

1)  Clamp or strap the piano to the tilter so the two cannot separate
until the piano is upright and stable.

2)  While righting the piano, manipulate the tilter to keep its two
prongs in firm contact with the piano bottom _while also keeping_
the tilter's 1/4-arc steel surfaces in firm contact with the floor.
(This is easy to demonstrate, more difficult to execute, and even
harder to describe!)

As an alternative, consider tipping the piano onto its side:  Place
a thick pad (folded mover's blanket) under the bottom/side corner
of the piano to protect the wood and prevent the pivot point from
slipping.  Then tip the piano onto a second blanket.  Two people makes
this easier and safer, though one experienced mover can do it alone.

Keep in mind that the piano's center of mass is quite close to the
_back_ of the piano, usually at the plane of the harp.  This makes the
piano much easier to tip backwards than forwards, and explains why
uprights almost always wind up on their backs in moving accidents.

John D. Rhodes - RPT
Vancouver, Washington