Caster cups

[Jim_Harvey@yca.ccmail.compuserve.com]

     Hi Keith,

     If it's the truth you seek concerning caster cups, then consider
     yourself set free!

     (A) Caster cups have fallen in and out of favor for many years. During
     a period in the '70s when they were being re-discovered, they were
     very difficult to find.

     (B) Caster cups are something that come free with many pianos. Since
     their inclusion is rarely mentioned at the time of sale, ahem...

     (C) Caster cups are often sold to new piano owners by piano movers as
     a custom accessory; i.e., the customer gets to buy them twice, thus
     encouraging continuing support of the free enterprise black market.

     (D) Excluding cosmetics(?), caster cups serve two basic purposes,
     regardless of the surface they rest on.
       1. They help prevent the piano from rolling during playing/tuning. I
     remember my first experience in tuning an SD on a hardwood floor,
     and... well, that's another story.
       2. They spread out the surface area normally occupied by the
     caster's moment of contact.

     I believe #1 to be self-explanatory, so will press on to #2.

     For the following, you may think of a car tire. At any one moment,
     there's a very small "footprint" supporting all that weight, and for
     that matter, the vehicle and occupants from disaster.

     If we consider that a grand piano represents a potential of, say, 300
     pounds per leg on whatever surface it rests on, all that potential is
     being concentrated into approximately one square inch at the bottom of
     the caster. Subsequently, that same weight is pressing _into_ whatever
     surface is below it.

     Pianos don't tend to 'free wheel' too much on carpeting. Likewise,
     modern carpets are very resilient -- they tend to bounce back from
     whatever impressions have been placed in/on them. However, in the case
     of high-pile carpeting, caster cups are often used to prevent the
     casters from disappearing from view in the carpet. Similarly, in some
     cases, the cups help offset problems relating to inadequate pedal
     travel _due_ to the carpeting.


     Other floor covering materials, such as asphalt or vinyl are not as
     resilient, or as forgiving. Over time, the divots left by the piano's
     casters become permanent reminders of where the piano used to be
     located.

     Under certain conditions, caster cups become a catch basin. If the
     customer has a pet that relieves itself on the piano leg, the
     resulting contamination _will_ effect the caster, axle, and/or socket.
     The caster cup helps prevent the resulting rust, verdigris, or what
     have you from transferring to the carpet.

     Other than this, it becomes a matter of customer choice. Some folks
     think that (just) because they have something, they must put it to
     use.

     Regards,

     Jim Harvey

     PS: Unrelated. You seem to be our unofficial keeper of the protocol on
     this list, i.e., helping folks who are having problems with listserv,
     AOL, whatever. I for one appreciate this. However, if Jim DeRoacher is
     not connected to the list, I doubt he'll ever see your message about
     how to connect to same.

___________ Reply Separator _________________
To use caster cups on a carpeted surface or not, that is the question.

'Tis the truest purpose for the invention of caster cups and their use, that
is which I seeketh.  Thereby being able to correctly counsel those customers
that ask.

In summary: In what situations should one use caster cups and when is it not
necessary?

Any input will be greatly welcomed by me to help resolve this matter for all
time.