Complex machines such as a car engine consist of many components. To build an engine, it is 'simply' a matter of assembling the components. There are several advantage to this method of manufacture:

• parts from one engine can be used in another engine (sometimes some modification is needed)

• often there are several parts (piston, valves etc.) which are the same in an engine. Because these parts are a copy of each other, the one mold can be used to make them all.

One of the great advantages of using CADD is that parts can be created, saved and reused.

ProDESKTOP CADD follows a similar logic:

• complex designs are an assembly of components

• components can be duplicated for use in a design

• one component may be used in a number of different designs

Creating an assembly design

When the components of a design have been created and saved, they are assembled into a new design.

To create an assembly design

• create a new design

• add each of the components

• duplicate components where necessary

• apply mating conditions between the components

Add a component

To add a component to a design

• from the Assembly menu select Add Component

• locate and open the file from the Open File dialog box

Fix component

After adding the main component of an assembly, it is important to fix the part into position. Failure to do so may result in the final design being at an unacceptable angle.

In the case of the vice assembly shown, the base has been fixed so the orientation of the design is set.

Align Axes

The axes of cylinders and holes can be aligned.

To align axes

• select the surfaces which define the axis

• EITHER

  • from the Assembly menu select Centre Axes

• OR

  • right mouse click

  • select Centre Axes from the menu

Align faces

Objects which are aligned have:

• a face in the same plane

• the body on the same side of the plane

Objects which are aligned may be moved to any position on the common plane unless they have other constraints applied.

Mate

Objects which are mated have:

• a face in the same plane

• the body on the opposite side of the plane

Objects which are mated may be moved to any position on the common plane unless they have other constraints applied.

Offset

Objects may be aligned or mated but with a distance separating the faces.

When applying this condition it is necessary to specify the distance between the surfaces and if an align of mating condition is required.

Offset dialog box

The distance is relative to the axes of the design. It may be either positive or negative, depending upon the direction of offset.

Orient

Orient sets the angle between selected objects faces.

Before the orient constraint can be applied, the two components must have their axes centred.

Hide a component

When assembling components, it is sometimes convenient to hide a component so others can be selected and assembled more easily.

To hide a component:

• select the component using the component tool from the design toolbar

• from the Assemble menu select Hide Components

Hidden components can still be seen in the Components browser. The icon representing the component is a skeleton rather than shaded.

Valve components (valve arm and valve part hidden)

To unhide a component:

• open the Components browser window

• right mouse click on the component which is hidden

• select Hide

Troubleshooting

Before starting to assemble, have a clear plan of what needs to be attached/aligned to what.

Applying mating conditions can cause headaches!

It is easy to attempt to over constrain the assembly and get the dreaded

message.

You have asked ProDESKTOP to do something which is not possible!

ProDESKTOP allows sizes of components to be changed in their original design. If a change in the original design would interfere with a mating condition in the assembly design, the mating condition is not allowed.

When a problem is encountered:

• check the Components browser to see what mating conditions have already been applied

• check which surfaces/edges are involved in the mating condition

• reconsider how to assemble the components

• if necessary delete some mating conditions

To delete a mating condition:

• open the Components browser

• right mouse click the condition

• choose delete from the menu