• Choose a category
• All
• Classic-Fiction

There is a five-way relationship between the Resolved, SpeedPak, Lightweight, Hidden, and Suppressed states, as shown in Figure 8.8.

FIGURE 8.8

The relationship between the Resolved, SpeedPak, Lightweight, Hidden, and Suppressed states

Comparing resolved to unsuppressed

The terminology becomes a little convoluted here because of the relationship between the five different states. In parts, the feature states are easy to remember because features can be either suppressed or unsuppressed. However, in assemblies, there are five states instead of two, and so unsuppressed could mean anything that is not suppressed, which still leaves three states. For this reason, resolved is used instead of unsuppressed when dealing with components in an assembly.

Using configurations for positions

When you use configurations to display an assembly in various positions, you can do it either by changing mates or by changing a layout sketch. Mates are configurable in two ways: mates can be suppressed and unsuppressed, and angle and distance mate values can be configured in the same way that sketch dimensions can be configured. Although creating a mate scheme that enables you to reposition the assembly using mate suppression states and values is essential to this method, it may not be the best approach. When mates are suppressed, then the components move, and if the mates are later unsuppressed, the assembly may not return to the original position. Mates can often be solved in different orientations, and may flip if turned on and off in this way.

Using a skeleton or layout sketch to mate parts may be a better approach, although this also has its drawbacks. If you mate to a layout sketch, you cannot use Dynamic Assembly Motion. If you use the mate scheme discussed previously, this generally means having a fully defined assembly, and this does not allow for Dynamic Assembly Motion.

As a compromise, a good way to handle this is by using one configuration for Dynamic Assembly Motion, with one or more open degrees of freedom. You can use other configurations to fully define the mechanism and show it in particular positions using either method. Probably the best way to demonstrate this idea is with an example using the robot arm assembly.

Positioning with mates

First, look at positioning with mates. On an assembly such as this one, the goal is to position the grippers. You can do this a couple of ways, both directly and indirectly. In the assembly used for this chapter, the grippers have been rebuilt as a subassembly, which allows different types of control. Notice that the subassembly has a configuration for the closed position and one that allows Dynamic Assembly Motion. In addition, the subassembly is being solved as Flexible. Figure 8.9 shows the assembly and the FeatureManager.

Driving the position directly

A sketch point has been added to the subassembly to identify the precise point on the gripper that is to be positioned. Sketch points have also been added to the main assembly to represent parts that need to be picked up by the robotic arm.

FIGURE 8.9

The assembly used for this example

Check the derived configurations under the default configuration. Notice that when you switch between certain configurations, the parts seem to separate. Moving one of the links causes the parts to snap back together again. This is probably because there are so many options when moving between configurations that the software has difficulty choosing a final position. This is definitely one of the potential problems when using configured mates to show an assembly in various positions.

Notice also that although the grippers are positioned correctly, the arm is still allowed to swivel around the intended target point. You can correct this by defining an orientation for the grippers for each location. If an additional pivot were added to the assembly, then fully defining the parts would become more difficult. The arm would not be able to reach