Creating a Compass assembly to understand mating constraints

In this task, you will create a Compass assembly and in the process understand different kinds of mating constraints. You will be using Bottom Up approach for assembly design and all the component model files are readily available in the sample folder of your program installation.

1

You will start with a New model file. The idea is to bring in each of the components as external references and assemble them with appropriate constraints. Use the X-Reference (component) command to bring in the first component Radial Arm into the new model file. Browse to the sample folder and select the file radial_arm.e3. Similarly bring in file lead.e3 Start the Mating command. In the selection list, make sure the Mode drop-down list (under More Options) reads Simple (and if it doesn't, select the Simple item). Click on the surface of the lead as shown for Object to be positioned. Note the program proposes the constraint Type as Coaxial (See the selection list), based on the geometry of the object selected i.e a revolved cylinder in this case. Next, move the cursor to select the blind hole on the Radial arm (radial_arm.e3) for Reference object.(See image below). Click on the blind hole to place the constraint. Mating Combination In this mating, the combination is of a revolved surface with Coaxial Type. The Coaxial constraint is created, and the command now lets you modify it or start creation of a new constraint.

2

You will now bring in two more components, the Pivot Arm(Pivot_arm.e3) and the Needle(Needle.e3) into the assembly file. For mating these two components, you will use the Inferred Mode. Start the Mating command. Click on the cylindrical surface of the Needle(Needle.e3) for Object to be positioned. Ensure the Mode drop-down list (under More Options) reads Inferred. Move the cursor near the blind hole on the Pivot arm(Pivot_arm.e3)and the program automatically identifies the constraint. Click on the blind hole to place the constraint.