Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!intran!tom
From: tom@intran.UUCP (Tom B.)
Newsgroups: comp.robotics
Subject: Re: Small Hovering Hobby Robots
Summary: postscript encoder disk
Message-ID: <369@intran.UUCP>
Date: 21 Jun 91 00:20:49 GMT
References: <00949D78.A594B600@vms.csd.mu.edu> <26776@ttidca.TTI.COM> <1991Jun19.164911.10552@areyes.com>
Organization: Xerox/Intran Corp, Mpls
Lines: 30


 lots of talk about encoders, here is one I used  written in postscript.


I wrote a simple postscript
program to create a 100 line disk. 

%Change to inches
72 72 scale
%setup a new line moving to center of page
newpath .03 setlinewidth 4.25 5.5 translate
%define number of lines
/lines 100 def
%Angle increment
/angleincr 360 lines div def
lines { 0 2 moveto 0 -2 lineto stroke
    angleincr rotate
} repeat
%draw white circle in center
newpath
.01 setlinewidth
0 0 .25 0 360 arc 1 setgray stroke
%eject page
showpage
%all done

I put this paper disk on a piece of 1/16" styrene.  The disk was glued
to the wheel using the silicone bathtub sealer.  Centering isn't
terribly critical, but I have a circle indicating where to cut the
hole for the axle.