Revolution of 2D geometry to create a torus-like shape (I'm getting distortion?)

I am trying to revolve a somewhat complex shape around a circle with radius R. The same idea as a taurus, but with arbitrary cross sectional geometry. However, I am getting distortion in multiple axis. I've included a code showing the problem and a picture of what is wrong.

 %%Problem script
  R = 1;
  N_phi = 80;

% Grab arbitrary disk coords in cartesian (example is a circle)
th = 0:pi/50:2*pi;
shape(:,1) = .25 * cos(th);
shape(:,2) = .25 * sin(th);
shape(:,3) = 0;

% Shift disk coords over by R
shape(:,1) = shape(:,1)+R;

% Convert back to spherical coords
[THdisk,PHIdisk,Rdisk] = cart2sph(shape(:,1),shape(:,2),shape(:,3));

% Make ring from individual disks
d_phi = 2*pi/N_phi;
THdisk2 = THdisk;
Rdisk2 = Rdisk;

for i = 1:N_phi
    PHIdisk2 = PHIdisk + d_phi*i-d_phi;

      % Convert back to cartesian coordinates.
      [ring(:,1,i),ring(:,2,i),ring(:,3,i)] = sph2cart(THdisk2,PHIdisk2,Rdisk2);
  end

hold on
for i = 1:N_phi
    plot3(ring(:,1,i),ring(:,2,i),ring(:,3,i),'ro')
end

grid on
axis equal
xlabel('x')
ylabel('y')
zlabel('z')