Design & Tech CAD

Level 1 Modelling

Level 2 Modelling

Level 3 Modelling


Sub Assemblies
Explode states & X sections
Bottom Up or Top Down Design
Building associativity through assemblies
Modelling in assembly mode

Model Analysis

Engineering Drawings

CNC Machining





Modelling in Assembly Mode

You can further develop your model by performing operations in the assembly file.  These come in two catergories:

Operations which exploit the relationship of parts in the assembly but have an effect at the part level, and,

Assembly operations which will only show at the assembly level as they would in reality.


** You could have issues if all parts are not fully constrained **


Component Operations*

Edit > Component operations.  Modelling which has an effect at the part level referencing the intersecting volumes of parts.

Cut Out - cuts one part with another.  Multiple parts can be selected.

Merge - merges one part into another.


Reference—References the second part to obtain its information. When the referenced part changes, the merged or cut out part changes.

Copy—Copies all the features and relations of the second part into the first.


Assembly Features

In a manufacturing environment many operations are performed to parts once they are assembled, eg. drilling holes, machining surfaces.  It is important to remember that although ultimately these features will change the shape of the part they do not exist at the part level.  therefore do not detail them in a part drawing, detail them in the assembly drawing.  Modelling features can only subtract material.

Assembly Features may be either Datum entities (Axes, Planes, Points, etc.) or subtractive solid geometry (Holes or Cuts).  All the normal functionality is available - extrude, revolve, sweep blend, etc.


* Boolean Operations - you may see reference to boolean operations in generic CAD discussion - union/merge, difference/cut, intersect.  See definition here.


Loughborough Design School© Sean Kerslake 2011