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Playing with Sheet Metal in

Autodesk® Inventor®

Kevin Burrows Technical Specialist – ECAD, Inc.

Lab Assistant: Jason Dupree – MFG Application Engineer – ECAD, Inc

Objectives

Describe the difference between sheet metal parts and

regular parts

Set up sheet metal styles

Create a sheet metal template file

Use basic sheet metal commands (face, flange, hem)

Goal for the Course

Images courtesy of ShopNotes®

Use Inventor’s sheet metal tools to create a

(dramatic pause)

Part 1:

Background info,

Rules, and

Templates

Definition Time!

What is a Sheet Metal Part?

Uniform thickness ← KEY FACTOR

Usually less than ½” thick

Uniform material ← No Multi-body sheet metal parts

“It’s like metal origami.”

--Kevin Burrows

AKA the putz teaching this class

Part Creation Process: Real World

Part Creation Process: CAD World

Part Creation Process: CAD World Calculating Flat Patterns: k Factor

k Factor – the ratio of the

neutral axis location

(measured from the inside

face) to the material

thickness.

k = 𝑡

𝑀𝑇

Calculating Flat Patterns: k Factor

k factor is one way to tell Inventor how to calculate a flat pattern:

We will use Outside Dimensions (OD) when measuring

folded models in this class.

Now, back to the

Bend Allowance Setback

How Inventor applies k factor:

𝐷 =𝜋𝐴 𝑅 + 𝑘 ∗ 𝑀𝑇

180− 2(𝑀𝑇 + 𝑅)

Definitions

D = amount deducted at each bend (bend compensation)

A = bend angle in degrees

R = inside bend radius

k = k factor

MT = Material Thickness

Calculating Flat Patterns: k Factor

Now we know how Inventor goes from

to

Calculating Flat Patterns: k Factor

… but how do we figure out a k factor that

works with our particular tooling?

Solving for k, we get:

𝑘 =180(𝐷 + 2 𝑀𝑇 + 𝑅 )

𝑀𝑇𝜋𝐴−

𝑅

𝑀𝑇

Definitions

D = amount deducted at each bend (bend compensation)

A = bend angle in degrees

R = inside bend radius

k = k factor

MT = Material Thickness

Calculating Flat Patterns: k Factor

Take a piece of scrap of

known length

Bend it

Measure the result

To find D, subtract the

total bent length from the

original length

Solve for k using the

previous equation

Calculating Flat Patterns: k Factor

Calculating Flat Patterns: Bend Tables

Demonstration:

Creating Unfold

Rules

1. Start a new sheet metal part

based on Sheet Metal (in).ipt

2. Click on Sheet Metal Defaults

3. Click the pencil icon to edit the

unfold rules

4. Create a new unfold rule called

.40 k Factor

5. Change the k factor to .40 ul and

save it

6. Create a new unfold rule called

BendTable using these settings

Practice: Creating Unfold Rules

Sheet Metal

Rules!

Sheet Metal Rules: Screens

Sheet Metal Rules: Screens

Sheet Metal Rules: Screens

Creating a Template: Where are

templates stored?

See your friendly

neighborhood

Application Options!

Demonstration:

Creating a Sheet

Metal Rule

Sheet tab Material: Steel, Mild

Thickness: 0.0747 in

Unfold Rule: .40 k Factor

Bend tab Relief Shape: Tear

Bend Radius: .03125 in

Bend transition: Straight Line

Corner tab 2 Bend Intersection: Tear

3 Bend Intersection:

Intersection

Practice: Creating a Sheet Metal Rule

1. Continue working in your

file

2. Click on Sheet Metal

Defaults

3. Click the pencil icon next

to the Sheet Metal rules

drop-down list

4. Create a 14 Ga Steel rule

based on the Default rule.

Settings

5. Save As->Template, then

close the file

Part 2: Basic

Sheet Metal

Features

Faces and Flanges

Face

Flange

Flange

Faces and Flanges

Face

Flange

Flanges

Flanges

Demonstration:

The

Episode 1

1. Start a new part based

on the template you

created

2. Create a 2D Sketch on

XZ Plane

3. Draw a Rectangle

4. Create Face

5. Flange the 2 short

edges

Practice: The Shelf Part 1

Hems

Demonstration:

The

Episode 2

1. Flange the 3 back

edges

2. Flange the front edge

3. Hem the front edge

4. Add corner chamfers

Practice: The Shelf Part 2

Sheet metal parts in Inventor must have uniform _____

& _______.

What must you do before creating a flange feature?

What is the difference between the sheet metal part

creation process in the real world and the CAD world?

What is k factor?

Review Questions

Objectives

Describe the difference between sheet metal parts and

regular parts

Set up sheet metal styles

Create a sheet metal template file

Use basic sheet metal commands (face, flange, hem)

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