Doing an Assembly –
Catia’s Answer
IE 1225 Introduction to Design &
Manufacturing
Dr. Richard Lindeke, Ph.D.
Issues we will explore:
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Using the Product Tree
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Part Command allows parts can be inserted into
the tree and designed “on the fly”
Components which are coupled into the
“CATProduct” but don’t exist as a separate entity
in its own file
Existing Component is used to insert an existing
part or assembly into the current Product
Sub-Assemblies are previously developed
Assembled Products that can be inserted into a
current product “all at once”
Considering Assembly Constraints:
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Coincidence Constraints: aligns axes, planes
and points
Contact Constraints: a tool for creating
contacts between 2 planes or surfaces
Offset Constraint: defines a desired offset
distance between two elements
Angle Constraints: A way to define an angular
relationship between two elements
Considering Assembly Constraints:
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Fix Component: A way to FIX a part “in
space” so that it will always remain there.
Other parts can be constrained relative to a
Fixed component
Fix Together: Fixes two parts together
(forever)
Flexible/Rigid Subassembly: in a flexible sub,
parts and components can be moved
regardless of the fact if it (or they) are the
active component
More Considerations:
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Use Save Management commands because
of the several links within the root tree
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Save or save-as individuals in the Save
Management window
We can also just “Save All” for a full update
When modeling because of constraining
issues, parts must have tolerenced
dimensions added
We Finish with an Assembly:
From Which we Make an Exploded Product
Drawing
Note: The
Product is
highlighted –
We can
explode and
assemble!
Building An Assembly
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Start Work in the Assembly Workbench
We begin with a “Root” CATProduct
We can create “Components” of the assembly that exist
only within the “Root Files”
We can inport Existing Components to the Assembly (parts
or sub-assemblies created earlier) W/ or W/O positioning
We can create Parts for the Assembly “on the Fly”
We can create “Instances” or duplicates of parts
We can create Numbers or Letters to Identify parts of an
Assembly – for BOM needs
We can “Manage Representation” (names, associations,
etc.) of the components of an assembly
We can Bring in Catalog – or standard – components to
our assemblies like bolts/nuts/pins, etc.
Because Assemblies are Multi-component
products get in the habit of ‘SaveManaging’
them and consider using Folders to save all
of the components and parts required
Lets Get Started:
Using Ass’bly I & properties to name it then Add
Part ICON to create Part1.1 under it & then
Properties/ set Instance Name to ToolPostBody
Draw a Profile on ZX plane as seen
Pad the Sketch to Dimension on Pg 5.1-7
Add Fillets to
Sides – as
specified in
Drawing Pg. 5.1-7
too!
Draw & Contrain the Profile on Large side – to
pocket
Add Main Thru Hole – Toleranced: .502 -.504;
Positioned as seen
Clicking Tolerance ICON (on hole) lets us
set the dimensions
Add 2 Threaded Holes – Finally Counterbored
Hole Positioned as seen:
Make Face Threaded Holes and Add
Material (Cast Iron)
This Part Is Finished – Save Manage!!
Add a Second Part (to ToolPost Assembly)
Draw a Profile for the Wedge – as Specified – note
Angle is 160!
Before Setting Slot Width – enter Tools …
Options: Set Tolerance Default to +0 -.012
Then set Slot Width 0.19;
Then turn Default Tolerance Off!
After Resetting Def.
Toler.; Exit Sketcher and
Pocket “Up to Last” Then
Save Manage
After Saving: Show Part 1 Attach the Compass to
The Wedge and Move it Away from the Tool Post
Body Part
Note: The
Compass is
Attached to the
Wedge – only it is
moving! When we
finish Click on the
Red Box and drag
it “Home (upper
Right Corner of
View)
Make a 3rd Part – BOLT- Make it as a Shaft; Careful
of Tolerance – Then Sketch and Pad the Head
Then Thread the End: ½ x 13 UNC for 1.25”
After Chamfer its End and Save Managing for the
Bolt; Un-Hide The Body & Wedge and Reposition
the Bolt
Standard Parts can be added We highlight the Assembly
Then Click Tool and Mech Std Parts – ASME, ANSI Inch
Catalogs
The set screws are inch Size Screws – use ¼ x 20 1.73”
headless – modify for proper length and End Form (Edit
Formulas)
After Adding it We can change its Name – Set
Screw 1 (or not) then save manage
A Second Headless Set Screw can be added By Copying
this: Rt. Click it .. Copy Then Rt. Click Tool Post Product and
… Paste – Move it where we desire
Add The ASME Nut (washer type) and Washer – position
them
Then Draw in the Rest of
the Components: The Tool
Post Screw (and make a
copy); Then Adj. Screw;
Finally Slotted Washer
and Adjustor Nut
Once all components are Drawn and Saved We add
Assembly Constraints – The Heart of the Task!
First A Contact
Constraint Between
The Bottom of the
Wedge and The top of
the Sloped Surface in
the T.Post Body
After Contact Constraint Between Wedge and T.P. Face A
very Useful Offset Constraint Between the Front Face of the
Body and The Wedge
Anchor (FIX) the Tool Post Body Then “Up Date”
to Bring the Wedge into Position
Apply Coincidence Constraints to the Axes of the
Set Screws and Body Holes – And Offset
Constraint To Back of Body and “Screw Slots”
Add The Rest of The Components & Their
Constraints for Assembly on Your Own
I had previously made and saved the ToolPost Screws – So I
added them as components w/ Positioning
They need to have coincidence
and Offset Constraints applied
for proper “Posing”
After the Copied Screw was constrained: