An Introduction to Assembly Arrangements with Unigraphics NX2

By John Lovingood

Intro to Arrangements

Arrangements are a way to show multiple positions of components within an assembly. They allow repositioning of an object in three translational directions, as well as three rotations.

Arrangements allow the user to keep an accurate assembly structure and avoid duplicates of components as is done with layer-based assembly positions. By using Arrangements, your Assembly structure will exactly match the Agile BOM.

Arrangements must be created with components, not just solid bodies or parasolids.

For Arrangements to work correctly, the mating constraints must allow the motion, i.e.. rotation or translation.

Arrangements do not depend upon Layers, the use of parameters, the Motion Application, altreps or multiples of the same component.

Arrangements should not be used in Specification (Drafting) files as this will disrupt Explosions (Keep Assembly in Default Arrangement).

There are several steps involved in creating Arrangements:

• Select the Assemblies Application.

• Turn on and bring the Arrangements column in the Assembly Navigator.

• Right click on the Descriptive Part Name header in the Assy Navigator. The select the Columns tab and then the Configure tab.

Intro to Arrangements

• Select the Arrangement Column and check the box beside it. Move it up through the list so that it is just under the Descriptive Part Name Column.

• When done correctly, the Assembly Navigator will look like this

• Next, add components and mate them per the assembly.

Intro to Arrangements

For this demonstration, we will create an Arrangement for a simple latch assembly. (arrangement_demo_jcl)

The assembly consists of a housing, a latch pawl, a shaft, a button and two screws.

Assemble the components per the design and use mating constraints. Be careful about aligning faces and mating surfaces.

In this example, the button moves back in the housing, pushing on the pawl, which rotates on the shaft. A spring preloads the latch against the button (not shown)

Intro to Arrangements

2. To create an Arrangement, select all of the components in the assembly, then right click to bring up the Component Properties Box.

• Select the Parameters tab and check the Individually Positioned box under Arrangements.

• The next step is to create the Arrangements. Right click over the assembly and select Arrangements and Edit.

Intro to Arrangements

If there are no Arrangements created, the column will be blank (there are none to choose from).

The Assembly Arrangements dialog box is now displayed. Arrangement 1 is the default arrangement, but can be renamed: stowed, deployed, up, etc. For this example, the default Arrangement will be “LATCHED”.

A second arrangement can now be created. This one will be called “UNLATCHED”. Use the copy button to create the second arrangement.

Intro to Arrangements

The green check shows which Arrangement is in use. The lower button allows an Arrangement to be set as the default. This is at the discretion of the user.

To setup the “UNLATCHED” Arrangement, select it and then check the Use button (top right), or double click it. Close the Assembly Arrangements window. The “UNLATCHED” Arrangement is now shown in the Arrangement column.

Intro to Arrangements

In this example, the button moves back 0.1in, and the latch pawl rotates around the shaft by 19°.

Reposition the components to their new position.

The Arrangements can now be toggled by right clicking on the assembly and then Arrangements and the desired Arrangement.

When the Assembly is saved, the active arrangement is set (i.e. will be loaded with part)

Intro to Arrangements

Arrangements can be stacked within assemblies and subassemblies.

To do this, simply create a new arrangement in an upper level assembly and set the lower level assembly to the desired arrangement. Then save the upper level assembly. Repeat as needed.

Ex. 1006065-001, 1005375-045, 1007342-015

As an example, see 1005375-045. In this case, the hinges, table leaves and rail have arrangements that are controlled at the top level.

Intro to Arrangements

By stacking arrangements, an upper level assembly could control all of the motion of the seat: TTOL, Z-bed, Lie flat, Foodtray deployment, Video Deployment, etc.

Intro to Arrangements

Lastly, be careful with arrangements if you are adding or subtracting components. Make sure that your arrangements still work properly. Otherwise, you will have components out of place =>

Notice the shroud that has moved, and the lone fastener in space. =>

Intro to Arrangements

Questions?

Intro to Arrangements