This step by step tutorial will expose you to Basic Sheet Metal commands through creating basic sketches, face, flange, cut and patterning.
Step 1: Create the First 2D Sketch
Create a new sketch on the XY plane. Use the dimensions shown and the 2 point center rectangle to create fully constrained geometry. Make sure your rectangles center point snaps to the origin of the sketch. Finish Sketch when complete.
Step 2: Create a Face From the 2D Sketch
Create a face using the 2D sketch you just created. Ensure the face is being created in the negative Z direction. Select OK to accept.
Step 3: Add Flanges to the Base
Create flanges on the top 4 edges of the part. Ensure angle and length have been input as shown in the figure. Leave the unfold, corner and bend options in their default state. Select OK to accept.
Step 4: Create 2D Sketch for Cut Command
Select one of the new flange faces and crate a new 2D sketch on that face. Within the sketch create an offset profile that is set in 1" from the outer most edge, as seen in the figure. Finish sketch when complete.
Step 5: Use Cut to Create Observation Window
Use the Cut command to cut the offset profile that you created in the previous step. See figure for detail. Select OK to accept.
Step 6: Circular Pattern the Cut Feature
Circular Pattern the Cut feature to create 4 windows on all sides of the vessel. Select the Cut feature from the window or the browser. Select the Origin Z Axis for the axis of the pattern feature. Select OK to accept.
Step 7: Flatten It
Create a flat pattern of the part you have created. Select Go to flat pattern in the top right corner of the model screen. Ensure you are on the Sheet Metal Tab if you do not see this option.