HG91007

The steps for the design of this exercise in AutoCAD are as follows:

Command: LIMITS
Reset Model space limits:
Specify lower left corner or [ON/OFF] <0.00,0.00>: 0,0
Specify upper right corner <420.00,297.00>: 90,60

Command: LINE
Specify first point: 0,0
Specify next point or [Undo]:  <Ortho on> 15
Specify next point or [Undo]: 40
Specify next point or [Close/Undo]: 50
Specify next point or [Close/Undo]: 40
Specify next point or [Close/Undo]: 15
Specify next point or [Close/Undo]: 55
Specify next point or [Close/Undo]: 80
Specify next point or [Close/Undo]: CLOSE

Command: REGION
Select objects: Specify opposite corner: 8 found
1 loop extracted.
1 Region created.

Command: EXTRUDE
Current wire frame density:  ISOLINES=4, Closed profiles creation mode = Solid
Select objects to extrude or [MOde]: 1 found
Specify height of extrusion or [Direction/Path/Taper angle/Expression]: 50

Command: CYLINDER
Specify center point of base or [3P/2P/Ttr/Elliptical]: 25,25
Specify base radius or [Diameter]: DIAMETER
Specify diameter: 15
Specify height or [2Point/Axis endpoint] <50.00>: -80

Command: SUBTRACT
Select solids, surfaces, and regions to subtract from ..
Select objects: 1 found
Select solids, surfaces, and regions to subtract ..
Select objects: 1 found

Command: CYLINDER
Specify center point of base or [3P/2P/Ttr/Elliptical]: 40,25
Specify base radius or [Diameter] <7.50>: DIAMETER
Specify diameter <15.00>: 50
Specify height or [2Point/Axis endpoint] <-80.00>: 38

Command: CYLINDER
Specify center point of base or [3P/2P/Ttr/Elliptical]: 40,25
Specify base radius or [Diameter] <25.00>: DIAMETER
Specify diameter <50.00>: 40
Specify height or [2Point/Axis endpoint] <38.00>: 38

Command: SUBTRACT
Select solids, surfaces, and regions to subtract from ..
Select objects: 1 found
Select solids, surfaces, and regions to subtract ..
Select objects: 1 found

Command: FILLET
Current settings: Mode = TRIM, Radius = 2.50
Select first object or [Undo/Polyline/Radius/Trim/Multiple]:
Enter fillet radius or [Expression] <2.50>: 25
4 edge(s) selected for fillet.

Command: UNION
Select objects: Specify opposite corner: 2 found