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AutoCAD and Its Applications—Advanced
O-Ring Groove
An O-ring is a circular seal that resembles a torus. It sits inside of a groove g
constructed so that part of the O-ring is above the surface. An O-ring groove can be
constructed by placing the center of a circle on the outside surface of a cylinder. Then,
revolve the circle around the cylinder. Finally, subtract the revolved solid from the
cylinder.
1. Construct the cylinder to the required dimensions, Figure 8-33A.
2. Rotate the UCS on the X axis (or appropriate axis).
3. Draw a circle with a center point on the surface of the cylinder, Figure 8-33B.
4. Revolve the circle 360° about the center of the cylinder, Figure 8-33C.
5. Subtract the revolved object from the cylinder, Figure 8-33D.
PROFESSIONAL P O TIP P PROF RO FE S SS I O O N A L T I I O NA NA AL T TI P P
In many cases, you will draw the O-ring as a torus. A copy of the
torus can be used to create the O-ring groove instead of revolving a
circle as described in the previous section.
Architectural Molding
Architectural molding features can be quickly constructed using extrusions. First, g
construct the profi of the molding as a closed shape, file Figure 8-34A. Then, extrude the
profi the desired length, file Figure 8-34B.
Figure 8-33.
Constructing an O-ring groove. A—Construct a cylinder; this one has a round placed on
one end. B—Draw a circle centered on the surface of the cylinder. C—Revolve the circle 360°
about the center of the cylinder. D—Subtract the revolved object from the cylinder. E—The
completed O-ring groove.
A B C D E
Figure 8-34.
A—The molding profile. B—The profile extruded to the desired length.
A B