3D CAD Example Tutorial: Office Chair Design (Part II)
In the first two tutorial articles, we have learned the design operation of the lower part of the office chair (legs, support parts), and in this article, we will complete the design of the upper part, that is, the back of the chair and the armrests. Below, we start a detailed introduction to the operation:
Step 1: Chair frame design
Using the Insert command under the Assembly page, insert the chair frame part at 0 coordinates and secure the component. Then look at the armchair assembly tree (Figure 1) and double-click to edit it.
Figure 1 Assembly tree
Sketch on the YZ work plane, noting that both ends of the straight segment should be 10mm out of each end, as shown in Figure 2.
Figure 2 Sketching
Stretch 300mm symmetrically, as shown in Figure 3.
Figure 3 Extrusion
If the face of the surface is reversed, use the Invert Surface Orientation to do the reverse, or redefine the Extrude command, check the Reverse Surface Orientation check box above.
Sketch Figure 4 on the XY work plane.
Figure 4 Sketching
The extruded sketch can be intersected with the previous surface, as shown in Figure 5.
Figure 5 Stretch sketch
Using the Intersection Curve, extract the intersection lines where the two surfaces intersect and hide unwanted faces, as shown in Figure 6.
Figure 6 Extracting intersections
Sketch Figure 7 on the XZ work plane.
Figure 7 Sketching
Stretch the sketch of Figure 7 to get the effect of Figure 8.
Figure 8 Stretching effect
Using the Intersection Curve, extract the intersection lines where the two surfaces intersect and hide unwanted faces, as shown in Figure 9.
Figure 9 Extracting intersections
Use the “Line” command to draw the two straight lines in the figure below and stretch the two lines to get the effect of Figure 10.
Figure 10 Draw a straight line and stretch it
Using the Intersection Curve, extract the intersection line where the two surfaces intersect, hiding the auxiliary surfaces that are not needed, as shown in Figure 11.
Figure 11 Extracting intersections
Create a new work plane, sketch on the work plane, and hide the secondary work plane after exiting, as shown in Figure 12.
Figure 12 Sketching
Use Sweep, using the outline drawn earlier, and using the Curve List at the path to generate the chair frame solid, as shown in Figure 13.
Figure 13 Chair frame solid
Round both edges by 5mm, as shown in Figure 14, and then use the “Shell Pull” command with a thickness of -2mm, shell the chair frame, and exit the part when finished.
Figure 14 Round
Step 2: Mesh design
Using the Insert command under the Assembly page, insert the fabric part at 0 coordinates and secure the component, then view the armchair assembly tree (Figure 15), double-click to edit.
Figure 15 Assembly tree
Using the Insert command under the Assembly page, insert the chair frame part with the 0 coordinate and fix the assembly, and use the Merge command to merge the chair frame geometry objects into the fabric part, as shown in Figure 16.
Figure 16 Merging
Delete the surface inside the solid object, including the rounded faces, to form the edge surface of the mesh, as shown in Figure 17.
Figure 17 Deleting a surface
Use the “Straight Surface” command under the Surfaces page to fill in the front and back sides of the mesh, and the effect is shown in Figure 18.
Figure 18 Mesh patching effect
Use the N-Side Surface command to complete the remaining 4 faces, complete the fabric design as shown in Figure 19, and exit the part.
Figure 19 Complete the mesh design
Step 3: Handrail design
Using the Insert command under the assembly page, insert the armrest part at 0 coordinates and fix the component, then view the armchair assembly tree (Figure 20), double-click to edit.
Figure 20 Assembly tree
Offset by 280mm along the YZ work plane to create a new work plane, as shown in Figure 21.
Figure 21 Creating a work plane
Sketch on the previous work plane, first using the Reference Geometry command to extract the guides, and in the middle of the guides, draw a straight line, as shown in Figure 22.
Figure 22 Sketching
Create a new work plane by offsetting the XY work plane as a datum to the target point, as shown in Figure 23.
Figure 23 Creating a work plane
Sketch on the previous work plane and use the Reference Geometry command to extract the guides, and the finished sketch is shown in Figure 24.
Figure 24 Sketching
Among them, the rounded corners and horizontal line dimensions are shown in Figure 25 below.
Figure 25 Rounded corners and horizontal line dimension effects
Create a new work plane and sketch as shown in Figure 26.
Figure 26 Sketching
Insert the Curve List, connect the first two sketches, and then use the Sweep command to use the outline and curve list paths drawn earlier, as shown in Figure 27.
Figure 27 Connecting sketches and sweeping them
The round angle is 10mm, as shown in Figure 28.
Figure 28 Rounded corner
Using the “Shell Pull” command, the wall thickness is -2mm, and the end face 29 below is the open face.
Figure 29 Shelling
Using the Mirror command, mirror half of the armrest to the other side, hide the unwanted work plane, curves, and curve lists, as shown in Figure 30, and exit the part.
Step 4: Color setting
Figure 31 is the default color, followed by the “chrome” texture settings for the legs, support bars, and support brackets.
Figure 31: Chrome texture settings
The seat frame, armrests, and mesh are set to black, where the mesh transparency is 60%, as shown in Figure 32.
Figure 32 Chairframe, armrest, mesh settings
Replace the legs and set the 4-jaw legs to a “chrome” texture, as shown in Figure 33.
Figure 33 Replace the legs
At this point, the design of the office chair is complete. The design of the entire office chair uses many commonly used curves and surfaces and other modeling functions, through the study of this example, I believe that everyone can master the operation of these functions well, and apply it to the modeling design of other products to design more practical and beautiful products.