If you go into the Model Workspace for smdoc_planetary_gear_e, you will see the MATLAB code that makes the carrier geometry with four "wings" for the planetary gears. If you look at that code, you will see the extrusion is modeled by simply drawing the arc between each pair of wings. Take a look at that, determine which values should be parameters, and modify it to suit your needs.
Code from Model Workspace is copy/pasted below.
--Steve
% Common Parameters
Rho = 2700;
T = 3;
A = 0.8;
% Sun Gear Parameters
Sun.RGB = [0.75 0.75 0.75];
Sun.R = 15;
Sun.N = 40;
% Planet Gear Parameters
Planet.RGB = [0.65 0.65 0.65];
Planet.R = 7.5;
Planet.N = Planet.R/Sun.R*Sun.N;
% Ring Gear Parameters
Ring.RGB = [0.85 0.45 0];
Ring.R = Sun.R + 2*Planet.R;
Ring.N = Ring.R/Planet.R*Planet.N;
Ring.Theta = linspace(-pi/Ring.N,2*pi-pi/Ring.N,100)';
Ring.RO = 1.1*Ring.R;
Ring.CSO = [Ring.RO*cos(Ring.Theta) Ring.RO*sin(Ring.Theta)];
Ring.CSI = simmechanics.demohelpers.gear_profile(2*Ring.R,Ring.N,A);
Ring.CSI = [Ring.CSI; Ring.CSI(1,:)];
Ring.CS = [Ring.CSO; flipud(Ring.CSI)];
% Gear Carrier Parameters
Carrier.RGB = [0.25 0.4 0.7];
Carrier.R = Sun.R + Planet.R;
Carrier.Theta = (180:-1:90)'*pi/180;
Carrier.Beta = (270:-1:180)'*pi/180;
Carrier.CS1 = Carrier.R*[1.08+cos(Carrier.Theta), -1.08+sin(Carrier.Theta)];
Carrier.CS2 = Carrier.R*[1.08+cos(Carrier.Beta), 1.08+sin(Carrier.Beta)];
Carrier.CS3 = -Carrier.CS1;
Carrier.CS4 = -Carrier.CS2;
Carrier.CS = [Carrier.CS1; Carrier.CS2; Carrier.CS3; Carrier.CS4];
% Joint Parameters:
b = 5e-4;
figure(99)
plot(Carrier.CS(:,1),Carrier.CS(:,2))
axis equal
