Colin Sledge and Joe King

Sledge & King

WHAT IS FDM?

FDM = FUSED DEPOSITION

MODELING

FUSED MELTING MATERIAL TOGETHER

DEPOSITION DEPOSITING MATERIAL

MODELING FEATURE CREATION

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WHAT IS FDM?

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WHAT IS FDM?

Normal CNC machining is subtractive

manufacturing

FDM is additive manufacturing

Both CNC machining and FDM use g-

code for control

Program written to file for every aspect

of part manufacturing

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WHAT IS FDM?

G type if motion

X,Y,Z coordinates

E,F feed rate

M machine commands

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FDM MATERIALS

ABS

PLA

PVA

NYLON

T-Glase

Filament with particles

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FDM MATERIAL

Not all material is the same quality

Use of different materials in one print for

support material

PLA and PVA can be dissolved away

from ABS parts

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PRINTER ANATOMY

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PRINTER ANATOMY

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PRINTER ANATOMY

0.4 mm

0.2 mm

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PRINT COORDINATES

Z Y

X

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PRINT FEATURES

IN X-Y PLANE IN Z PLANE

TOP VIEW FRONT VIEW

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INTERIOR PART DESIGN

Shells Passes around surface boundaries

Infill Percent of interior volume that is material

Infill Pattern Defined by slicing program (cylinders, rectangles,

hexagons)

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SLICING PROGRAM

STL and OBJ files

are input into the

slicing program

Slices part in z-axis

Part defined by

surface boundaries

Solid features structure is program

defined

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SLICING PROGRAM

Dual extrusion prints integrate multiple

parts into a single print

Each part component must be a separate

file (Think Nut & Bolt)

Dual extrusion parts are Aesthetically

pleasing with multiple colors

Use of dual extrusion for better supports

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COST OF 3D PRINTING

Small Machines - $1200-$2200

Material - $30-$100 per kilogram

Maintenance - ~$100 for lifetime

(variable)

Electricity 350 watt power supply

Comparable to desktop computer

Kilowatt hour ~$0.15 (http://www.npr.org)

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COST OF 3D PRINTING

Imagine machine is discarded after 1500 hours

1200/1500 to 3300/1500 = $0.8 to $2.20 per hour

30*10/1500 = $0.2 per hour

200/1500 = $0.14 per hour

(350/1000)*0.15 = $0.05 per hour

Total cost per hour = $1.19 to $2.59

Additional costs include overhead for rental space and technicians (expect ~$5 per hour) Sledge & King

3D PRINTING ACCESSIBLITY

3D Printing is accessible to YOU!

There is a wide range of machines and

prices of machines

Many large companies utilize 3D

printers and rapid manufacturing

Understanding the fundamentals will

make you an asset to a company

3D PRINTING IS HERE TO STAY!

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USING THE SLICING PROGRAM Rep-G MakerWare

More customizable

Stronger Parts*

Hard to use for Dual

Extrusion

More advanced

Slower

Great for Dual Extrusion

More intuitive user

interface

Part Preview

More difficult to

customize

Faster

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Rep-G

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MakerWare

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MakerWare

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PART PREPARATION

Check part for printability

Decide best orientation for printing*

Add bottom plate to part to mitigate

peeling and provide a clean surface

Modeled plate provides better support than

rafting and will maintain a better surface

Check slicing program and g-code

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CHECK FOR LEVEL BUILD PLATE

Check added model plate for air gaps

and rough texture

Use only minor adjustments

Only adjust when machine is warm

TOO FAR PERFECT* TOO CLOSE

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DESIGNING THE STRENGTH OF

THE PART

Choose the shells and infill to satisfy

strength requirements

More infill and more shells requires

more time to print

Both shells and infill are important to

part strength

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DESIGNING THE STRENGTH OF

THE PART

5% Infill & 5 Shells 10% Infill & 2 Shells 50% Infill & 1 Shell

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DESIGNING FOR PRINTING

It is necessary to foresee the

manufacturing process to determine the

best way to design a part

Determine minimum size of features

Like wood in terms of orientation for

strength*

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FREEDOM AND BENEFITS OF 3D

PRINTING

Rapid Prototyping

Complex Features

Intricate Details

Tooling

Molding

Presentations

Useable Parts!!!

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RAPID PROTOTYPING

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COMPLEX FEATURES

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INTRICATE DETAILS

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TOOLING

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MOLDING

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PRESENTATIONS

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USEABLE PARTS

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USEABLE PARTS

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MODELING ORIENTATION

In conjunction with orientation for

strength, orientation is also important for

printability

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MODELING ORIENTATION

IN Z PLANE

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INVERTED ANGLES

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INVERTED ANGLES

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INVERTED ANGLES

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INVERTED ANGLES

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INVERTED ANGLES

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OVERHANGING FEATURES

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OVERHANGING FEATURES

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FLAT SURFACES ARE BEST

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ROUND EDGES AND ARCHES

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ARCHES

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HOLES

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HOLES

Holes SHOULD NOT be drilled in post

process

Holes can be minimally enlarged or cleaned*

DO NOT Band-Aid parts!

Fasteners can be screwed into

appropriately sized holes

Lightening holes DO NOT always lighten

the part!

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THREADS

Internal and External threads can be printed and used

The part must be large to ensure threads are a printable size*

Vertical orientation will print easier but will not be as strong while sideways orientation will need to supported but will provide stronger threads

Threads should not come to a point and should be round if possible (FDM Design Handbook, 3rd Edition, Stratasys)

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THREADS

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INCORPORATING FEATURES

Parts should be designed to minimize

post processing

Unlike many machining processes,

additional features do not require tool

changes or much additional time, thus

additional expense

Added features often make the part

stronger and require less post

processing

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INCORPORTATING FEATURES

When adding features, be mindful of

feature orientation and loading

Often compromises are made

Determine if it is better to develop part in

multiple piece and screw or glue in post

processing

Curves print better in the X-Y plane

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INCORPORATING FEATURES

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INCORPORATING FEATURES

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INCORPORATING FEATURES

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STRENGTHENING FEATURES

Because the interior of parts are not solid, adding curves, cuts, and holes tend to strengthen parts, as this adds part boundaries, thus more shelled area

This can be used to add material near holes that screws tap into or holes that may be drilled out Of course, as noted previously, DO NOT drill the

part without designing the hole into the print

The strength often comes at the expense of weight

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STRENGTHENING FEATURES

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STRENGTHENING FEATURES

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SUPPORTS

Supports can be model defined or slicer

defined

Supports can be model from a different,

dissolvable material with a dual

extrusion printer

If supports are model based, make sure

to leave an appropriate gap between the

part: ~ 2 layers in each direction (If

break-away supports are used)

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SUPPORTS

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SUPPORTS

MakerWare

designed support

features can be

useful

Quick, yet not as

customizable

Great if you do not

have access to CAD

software

(www.makerbot.com) Sledge & King

SUPPORTS

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3D PRINTING FOR MAE

PROJECTS

Has the potential to greatly improve the

quality and functionality of your projects

This is NOT magic and DOES NOT

happen instantly

3D printing is an iterative process

3D printing is NOT a remedy for bad

engineering

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ENGINEERING DISCOVERY

3D printing allows you to explore your

designs and skills

Only you can discover the nuances of

3D printing to become an expert at

designing for additive manufacturing

HAVE FUN!

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3D PRINTING RESOURCES

ON-CAMPUS 3D PRINTING RAPIDTECH (4th floor Engineering Tower)

BUY YOUR OWN FlashForge www.ff3dp.com

Talk to Joe King*

MakerBot - www.makerbot.com

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