clear all
N = 10;
rout = 126e-3;
rin = rout/(4*N+1);
spacing = (rout-rin)/(4*N)
width = spacing
a = 2*width/pi
theta = [0:pi/1000:2*pi*N];
r1 = rin+a*theta;
x1 = r1.*cos(theta);
y1 = r1.*sin(theta);
r2 = 2*rin+ a*theta;
x2 = r2.*cos(theta);
y2 = r2.*sin(theta);
theta2 = theta + pi;
r3 = rin+a*theta;
x3 = r3.*cos(theta2);
y3 = r3.*sin(theta2);
r4 = 2*rin+ a*theta;
x4 = r4.*cos(theta2);
y4 = r4.*sin(theta2);
plot(x1, y1 ,'r', 'LineWidth', 4); grid on; hold on;
plot(x2, y2 ,'r', 'LineWidth', 4); grid on; hold on;
plot(x3, y3, 'LineWidth', 4); grid on; hold on;
plot(x4, y4 , 'LineWidth', 4); grid on; hold on;
axis ('equal')
rotate3d on
z = [x1,y1,x2,y2];
z = [x3,y3,x4,y4];