In Project Schematic, double click on Geometry to open the Design Modeler. When prompted, select Millimeter as the unit.
Click on the XY Plane and the z axis to begin sketching. Use the Line sketching tool to create a vertical line starting from the x axis . Hover the cursor around the axis until you see a symbol C to begin your sketch. The symbol C means the line is coincident with the x axis. Next, use the Arc by Center to create the dome of the shell. Hover the cursor near the y axis until you see the symbol C. Single click on the y axis and click again on the tip of the line you have just created. You should see a symbol P when you click on the vertex, which means coincident. Finally, click on the y axis again to finish the arc.
Use the General dimension tool to create dimensions for the line and the radius of the arc. The length of the line is 30 mm and the radius of the arc is 25 mm. Your sketch should look like this:
Click on Create from the top menu bar and select Revolve . The Revolve tool should automatically select your shell sketch for its geometry. If not, highlight the cell next to geometry and select Sketch1 under the XYPlane tree. Select the Y axis for Axis . This will allow the sketch to revolve around the y axis to create a shell. Change the Angle from 360 to 90 degrees. Highlight As Thin/Surface? and change the option from No to Yes . Keep the Inward Thickness at 1 mm. Click on Generate.
The 1/8 shell model