% Program: Involute Gear Profile Generator 
% Robert Jackson, Auburn University, 2008

d=2.814; %Base Diameter of Gear
r=d/2;
dp=3; % Pitch Diameter
do=3.25; %Outer Diameter
size=50;
NT=80;  % Number of gear teeth
t2=2*pi/NT

for n=1:size
t=(n-1)/size/2.5;
ang = t * pi/2;
s = ( pi * r / 2 ) * t;
yc = r * cos(ang);
xc = r * sin(ang);
y(n) = yc + ( s * sin(ang));
x(n) = xc-( s * cos(ang));
RAD=sqrt(y(n)^2+x(n)^2);
theta=atan(x(n)/y(n));
y(n)=RAD*cos(theta-t2);  %+pi/10%
x(n)=RAD*sin(theta-t2);
y(n+size)=y(n);
x(n+size)=-x(n);
yc = r * cos(pi/10*t);
xc = r * sin(pi/10*t);
y(n+2*size)=yc;
x(n+2*size)=xc;
y(n+3*size)=yc;
x(n+3*size)=-xc;
y(n+4*size)=yc*do/d;
x(n+4*size)=xc*do/d;
y(n+5*size)=yc*do/d;
x(n+5*size)=-xc*do/d;
end

figure(1);
plot(0,0);
axis([-.25 .25 1.25 1.75])
hold;
for n=1:size*6
plot(x(n),y(n));
end
% list x and y coordinates to be cut and paste for use outside of Matlab
x'
y'