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Incorporated, a worldwide network of science museums and related institutions.
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I have had trouble with ALL trackballs that are mounted on a slant.  
Bottom line, obey gravity!
Beryl

Dave Watkins wrote:
> ISEN-ASTC-L is a service of the Association of Science-Technology Centers
> Incorporated, a worldwide network of science museums and related institutions.
> *****************************************************************************
>
> 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!
>
>   

-- 
Beryl Rosenthal, Ph.D.
Director
Tsongas Industrial History Center
Boott Cotton Mills
115 John Street
Lowell, MA 01854
(978) 970-5081 (t)
(978) 970-5085 (f)
[log in to unmask]
www.uml.edu/tsongas

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