1. Top down assembly
Presented by-
Dilip kumar garg
Jayant sarode
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2. Assembly
• Assembly modeling is the process of creating designs
that consist of two or more components assembled
together at their respective work positions.
• The components are brought together and assembled
by applying suitable parametric assembly constraints
to them.
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4. Assembly Modeling Approaches
• Bottom Up Assembly
• Top Down Assembly
• Combination
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5. Bottom Up Assembly
• Traditional approach
• Parts are created individually in the part mode
• Inserted into the assembly, located and oriented
(using the constraints) as per requirement
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7. Pros and Cons
• Allows the designer to use part drawings that already exist (off the
shelf).
• Provides the designer with more control over individual parts.
• Any changes in the original part is reflected on all the instances in the
assembly
• Assembly files created in this method occupy less disc space as they
contain only the information related to the assembling of the parts.
• Errors are manually identified and modifications to each component are
made to make the adjustment.
• If any of the assembly components is moved from its original location,
then the assembly will not open.
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8. Top Down Assembly
• Assembly file is created first with an assembly
layout sketch.
• The parts are made in the assembly file itself and
then assembled using assembled using assembly
constraints.
• The new parts are created relative to other
components.
• We create a skeleton first at the top of the
hierarchy and move down the hierarchy, creating
subassemblies and components.
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10. Skeletons
What is it
• Zero-mass geometry
• Exact location detail
• Minimized geometric detail
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11. Definitely Not this
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12. Example to Design an Alternator
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All Skeleton Models
in Top-Level
Assembly
70 MB
Subassembly,
with Skeleton Model containing
all required information ~ 20 MB
Complete Top-Level
Assembly
540 MB
Neighboring
Subassemblies
320MB

13. Assembly of by top Down Approach
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14. Pros and Cons
• The overall design information is in one centralized
location
• Reduce errors within complicated assemblies
• Increased quality
• Better project management visibility
• Concurrent engineering
• Top-level change control
• The approach is ideal for large assemblies consisting of
thousands of parts.
• Creating the top down assembly require more analysis
and work before start
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15. Applications of top down Assembly
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