Re: TDC projector selectron carrier

[P3D John W Roberts <roberts@xxxxxxxxxxxxxxxxx>]

>Date: Sat, 11 Oct 1997 17:13:01 -0500
>From: P3D Linda Nygren  <lnygren@xxxxxxx>
>Subject: TDC projector selectron carrier

>I have two different selectron carrier units, and each seems a little
>stiff when the slide carrier is pushed in and pulled out. When  actually
>installed in the projector, there is so much resistance that it is
>almost impossible to push it in. I'm not sure why tightening the
>thumbscrew would make that much difference....

I don't know about selectron carrier units, but there are many cases where
even a very small increase in lateral pressure results in an enormous increase
in friction force. A capstan is a classic case of a machine which makes
use of this effect.

John R


------------------------------