• Engineering 1182

College of Engineering

Engineering Education Innovation Center

Assembly Modeling Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 1

• Engineering 1182

AssembliesAssemblies are collections of 3D

parts that form one engineering

system

1. Modeled to Fit Together

2. Location defined by 6 degrees

of freedom

• 3 translational (x,y,z)

• 3 rotational (about x,y,z axes)

3. Assembly Constraints• Concentric

• Mating Surfaces

• Coincident

• Distance

Rev: 20130715 AJP Assembly Modeling Constraints 2

• Engineering 1182

Modeled to

Work Together

• Compatible

Components

• Dimensional

constraints

• Assembly

Constraints

• Operational

Requirements

Rev: 20130715 AJP Assembly Modeling Constraints 3

• Engineering 1182

• 6 degrees of

freedom constrain

an instance of a

part file

• X,Y,Z Translation

• X,Y,Z Rotation

Defining

Location

Rev: 20130715 AJP Assembly Modeling Constraints 4

• Engineering 1182

• Concentric

• Mating Surfaces

• Coincident

• Distance

Assembly

Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 5

The bridge example will be

used to demonstrate these

core concepts

• Engineering 1182

Concentric Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 6

Axes of cylindrical features and

holes can be selected

Concentric constraints align

centerline axes

• Engineering 1182

Mating Surfaces

Rev: 20130715 AJP Assembly Modeling Constraints 7

2D surfaces can be mated to become

flush with one another but the correct

direction must be given to the computer

• Engineering 1182

Additional Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 8

Distance between

entities if not flush

Coincident Lines or

Vertices

• Engineering 1182

SolidWorks Adding Components

Rev: 20130715 AJP Assembly Modeling Constraints 9

In the Assembly tab (similar to

the Features tab of a Part file)

use the Insert Components

button to add part files to this

assembly

Select from the open

parts listed or use the

Browse to find saved

files

• Engineering 1182

After placing the base part, reopen the Insert

Component dialog box and click on the pin to keep

the box open. Now browse and double click on or

Open the second part and left SINGLE click in

SolidWorks window to place second part. Next go to

the Insert Component dialog box and single left click

on the second part just inserted so that it’s blue

high-lighting is removed. Now click on browse and

select the third part, left SINGLE click to place it, left

click on the third part in the Insert Component dialog

box to remove the blue high-lighting and repeat

sequence. After placing the last part, select the

green check mark or hit ESC to complete the

insertion of parts. Note that if multiple copies of any

part are needed, one can SINGLE click again after

the part has been placed to produce another copy of

the part.

SolidWorks: First Component

The first part inserted will

become fixed in space and

should be placed at the

origin as a base for the

assembly.

This must be done by

selecting the part and then

clicking the green check

mark to default to the origin

instead of just left clicking in

space.

ANCHORING THE

BASE AT THE

ORIGIN

INSERTING

ADDITIONAL PARTS

• Engineering 1182

SolidWorks Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 11

In SolidWorks these are the

Standard Constraints used in

Assemblies

In the figure window it

will show a preview of

the mating and a smaller

dialog box will appear

Change Direction Confirm Mate

• Engineering 1182

SolidWorks ExampleAssembly of a water

filtering pitcher

Rev: 20130715 AJP Assembly Modeling Constraints 12

• http://youtu.be/1s-

1CUoq1zE

• Engineering 1182

Water Pitcher Example

Rev: 20130715 AJP Assembly Modeling Constraints 13

To start lets bring in

the pitcher and top

compartment and mate

their two back surfaces

• Engineering 1182

Water Pitcher: Top Compartment

Rev: 20130715 AJP Assembly Modeling Constraints 14

Similar constraints are added to the

sides and top ridge in order to fully

constrain the top compartment

• Engineering 1182

Water Pitcher: Filter

Rev: 20130715 AJP Assembly Modeling Constraints 15

Now lets add to our

assembly the water

filter which fits into

the circular hole of

the top compartment

• Engineering 1182

Water Pitcher: Inserted Filter

Rev: 20130715 AJP Assembly Modeling Constraints 16

The bottom ridge of the

filter and the top of the

compartment are selected

and the faces are

constrained to be flush

• Engineering 1182

Water Pitcher: Section View

Rev: 20130715 AJP Assembly Modeling Constraints 17

A section view can be used

in order to see that the

mates are correct

Choose the correct plane

that cuts through an object

• Engineering 1182

Water Pitcher: Sub-Assembly

Rev: 20130715 AJP Assembly Modeling Constraints 18

The top cover of the water

pitcher consists of 2 pieces

that were put together in a

separate assembly and

then brought into the

current assembly

• Engineering 1182

Deleting Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 19

All Constraints applied

are located in the Model

Tree under Mates

• Engineering 1182

Deleting Constraints

Rev: 20130715 AJP Assembly Modeling Constraints 20

Constraints can be

selected and removed

using the delete key

• Engineering 1182

Assemblies Wrap-Up

• Assemblies – collection of 3D parts that form a system

• 6 Degrees of Freedom• XYZ Translation

• XYZ Rotation

• Assembly Constraints• Concentric

• Mating Surfaces

• Coincident

• Distance

Homework Assignment:Buck-Eye-Phone Assembly

Rev: 20130715 AJP Assembly Modeling Constraints 21

• Engineering 1182

In-Class Assignment

Rev: 20130715 AJP Assembly Modeling Constraints 22

Using the pre-made

blocks and wheels

construct a pinewood

derby racer using

assembly constraints

A starter assembly is

provided that is the basis for

the In Class exercise

Application Folder > IN-Class Problem Pinewood Derby Racer >

Starter Assembly > PINEWOOD RACER START ASSEMBLY