Part III: Working with Assemblies
FIGURE 13.16Setting up a Screw mate
Screw mates can be handy for lead screw animations. I would probably not recommend them for
general modeling, but for animations, they are a fantastic addition to the mate toolbox.Path mate
The Path mate is the one that makes complex barrel cam motion possible, as well as other types of
path driven motion. Another application for this mate type beyond barrel cams is for the motion of
a camera in a fly-through animation. The Path mate requires a point or vertex on one part and a
curve selection in a second part. The path selection, if it is not just a single sketch or curve entity,
requires the use of the SelectionManager, which enables you to select multiple end-to-end entities
to form closed or open paths. Figure 13.17 shows the setup for a Path mate.
Note
On the barrel cam in Figure 13.17, notice that a sketch point is being driven along the path. In reality, this
does not exactly reflect the motion of the follower around the cam surface. The Path mate does not take into
account the tangent contact point between the surfaces; it simply drives the point along the curve. There is a
slight amount of error in this scenario, such that the leading or trailing surface of the follower will interfere
with the cam, depending on the angle of the cam surface. Also note that the Path sketch entity has nothing to
do with the Path mate; it is not required to make the Path mate work. n