Steinway casters orientation

[JIMRPT@aol.com]

In a message dated 16/01/04 10:00:48 AM, 741662027@charter.net writes:

<< What is the mechanical reason that the caster orientation has an effect on

keyframe bedding?  Is it simply that different orientations cause the leg to

be slightly longer or shorter?


--Cy Shuster-- >>

Cy...as Ron said..."everything is the casters fault" :-)
 My opinion is that the forces acting on the keybed will 'slightly' change 
the flatness of the keybed. "change" is relative to the dimensions involved of 
course. With the casters turned sideways..rolling toward the side of the 
piano... I 'think' there is an induced curvature to the board from the weight of the 
piano causing the legs to try to go in opposite directions....mostly I 
'think' the legs try to go away from each other.

 In any event there is a simple and direct test for this type 
thingee.........Do a good regulation of a grand with the caster knuckles oriented toward the 
keys and when you are satisfied with the regulation orient the caster knuckles 
toward the sides and observe the effect on your regulation......you might 
need to let the piano set for a couple of hours to observe the difference but it 
will show up....this thingee is particuarly noticeable on S&S but is apparent 
on all makes in my opinion.
Jim Bryant (FL)