Assembly modeling involves combining two or more components using parametric relationships. A designer typically starts with a base part and adds other components to it using merge commands. An assembly can be modeled using a bottom-up or top-down approach. Bottom-up involves using existing part drawings, while top-down is ideal for large assemblies with multiple teams. Components can be mated using basic mates like coincidence or advanced mates like cam and hinge joints. Degrees of freedom allow movement along X, Y, and Z axes or rotation, while mating conditions define relationships between parts.

1. ASSEMBLY MODELING
By :
Ameya Nijasure

2. Introduction
• Assembly modeling is a combination of two or more
components using parametric relationships.
• Typically a designer would start with a base part
• Add other components to the base part using merge
commands.

3. pulley block
(assembly)
hook
(subassembly)
hook crosshead thrust
bearing
dust
cover
lock
nut
hex
nut
distance
bolt
pulley
(subassembly)
pulley pulley pin bush
cover plate
(sub assembly)
cover
plate
lock
plate
Assembly Tree

4. Exploded view
An exploded view
consists of series of
steps. One can
create steps by
selecting and
dragging parts in
graphical area.

5. Assembly of Pulley block -:
Exploded view Assembly view

6. Bottom-up assembly approach -:
• Allows the designer to use part drawings that already
exist (off the shelf).
• Provides the designer with more control over
individual parts.
• Multiple copies (instances) of parts can be inserted
into the assembly.

7. Top-down assembly approach -:
• The approach is ideal for large assemblies consisting
of thousands of parts.
• The approach is used to deal with large designs
including multiple design teams.
• It lends itself well to the conceptual design phase
• E.g. :
▫ Piping and fittings
▫ Welds
▫ Lock pins

8. Degrees of freedom -:
• Translation – movement along
X, Y, and Z axis.
• Rotation – rotate about X, Y,
and Z axis.

9. Mating conditions -:
Basic mates Advanced Mates
• Coincidence
• Parallel
• Perpendicular
• Tangent
• Concentric
• Lock
• Angle
• Distance
• Distance
• Linear/linear coplanar
• Path
• Width
• Symmetry
• Angle

10. Mechanical mates:
• Cam
• Hinge
• Gear
• Rack Pinion
• Screw
• Universal Joint

11. References
• Vedaraman Sriraman “Assembly Modeling”
Southwest Texas State University 1991
• ZeidJ. (1991). CAD/CAM theory and practice.New
York, NY: Mc Graw - Hill, Inc.
• http://www.pinterest.com/pin/332633122448473315/
(Date : 05/11/2014)
• http://www.engr.sjsu.edu/youssefi/me265/notes/8%20
-20Assembly%20Modeling.pdf (Date : 25/10/2014)

12. Thank You….