Date:    Wed, 24 Jul 2002 08:27:22 -0700
From:    pensioner <al_knoll@PACBELL.NET>
Subject: Speedo Stuff

"IIRC a speedo works on a rotating magnet plate working against an iron
disk
spring loaded by a calibrated spring ......"

I think you will find that the plate or cup attached to the speedometer
needle is not iron, but aluminum.  Otherwise, great description of how
the traditional speedometer works.