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Date: | Wed, 5 Dec 2007 10:31:54 -0500 |
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ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
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Allan,
There are challenges when Happ Trackballs are mounted less (or more) than
horizontal. As you probably know, they operate on two 90 degree internal
contacts.
You are correct; it is that old gravity thing. When a trackball is mounted
at an angle, more pressure is placed on one contact than the other. It may
not hang-up, but it is not as fluid.
We did a Visitor Center for one of the NASA Centers and changed the design
so the trackballs were all mounted horizontal.
That being said, Happ makes very reliable products.
Regards,
Dave Watkins
Impact Communications
216-861-1063
-----Original Message-----
From: Informal Science Education Network
[mailto:[log in to unmask]] On Behalf Of Allan Ayres
Sent: Tuesday, December 04, 2007 6:05 PM
To: [log in to unmask]
Subject: quick Happ trackball question
ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related
institutions.
****************************************************************************
*
Is anyone aware of any issues with mounting a Happ trackball in an
inclined panel (say, 30 degrees from the horizontal)? Does the ball
sag down with gravity over time and eventually lose contact with the
rollers inside the trackball assembly?
If anyone can share any experiences one way or the other, that would
be a big help. Many thanks!
--
~~
Allan Ayres
Exhibit Developer
Lawrence Hall of Science
University of California, Berkeley
Berkeley, CA 94720-5200
[log in to unmask]
510-642-1254
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