Office Chair CAD Steps

The CAD drawing of office chairs mainly involves two methods: 2D planar drawing and 3D modeling. The specific steps are as follows:

2D Planar Drawing Steps

1. Drawing the Chair Outline

   • Seat Frame: Enter L (Line) in the command line and press Enter. After determining the starting point in the drawing area, draw the preliminary outline of the seat. Use the CO (Copy) command to copy parallel lines at an appropriate offset distance, gradually outlining the left and right side lines to form a rectangular seat frame.
   • Backrest Outline: Enter the ARC command (or through [Draw] - [Arc] - [Three Points]) to draw an arc at the back of the frame as the curved outline of the backrest. Use the L command to draw a vertical line at the backrest position, and then use the MI (Mirror) command to generate the other side's symmetric line with the central axis as the axis of symmetry.

2. Dimensioning
   Use the DLI (Linear Dimension) command to dimension the chair. The reference dimensions of an office chair are: height 40-45 cm, length and width both approximately 45 cm. When dimensioning, ensure that key dimensions (such as seat length and backrest height) are clearly visible for subsequent modifications or production references.

3D Modeling Drawing Steps (Partial Examples)

1. Drawing the Basic Arc
   Click the arc button in the drawing toolbar or press the shortcut key ARC, and select the "Center, Start Point, Angle" method to draw. For example, enter C to determine the center point, enter the relative coordinates @200,0 at the "Specify Start Point", and then enter the included angle 180 to draw a semicircular arc with a radius of 200.

2. Drawing Concentric Arcs
   Use the same method to draw a concentric arc with a radius of 170, ensuring that the centers of the two arcs coincide. This step serves as the curved surface foundation for the backrest or armrests.

3. Drawing Vertical Lines
   Draw four vertical lines (length 200) at the four points of the two arcs respectively. When drawing, turn on the ortho mode (press F8) to ensure that the lines are perpendicular to the arc plane.

4. Connecting Lines to Form a Curved Surface
   Use the L command to draw connecting lines between the endpoints of the four vertical lines, also turning on the ortho mode to ensure that the lines are horizontal or vertical. After completion, commands such as "Extrude" and "Revolve" can be used to generate solid models, or the "Mesh" tool can be used to construct curved surfaces.

Notes:

• In 2D drawing, pay attention to the closure of the outline for easy subsequent 3D conversion; in 3D modeling, reasonably set the view direction (such as SW Isometric) for easy observation of the structure.
• Dimensioning should comply with engineering specifications, avoiding ambiguous or duplicate dimensioning; the 3D model can be checked for the rationality of the internal structure using the "Hide" command.
• In actual drawing, parameters (such as arc radius and line length) can be adjusted according to needs, but the overall proportion should be kept coordinated.