ThermoFab Design Guide

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76 Walker Road, Shirley, Massachusetts 01464 USAT 978.425.2311 F 978.425.2305 www.thermofab.com

Custom Plastic Enclosures. Revolutionary Process.

Design Guide


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Design Guide

The intent of this guide is to assist theengineering team in their work to design custom

plastic enclosures.

This guide will also include considerations forproduct design when designing custom plastic

enclosures for ThermoFab.


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Table of Contents

1.0 Design Basics

1.1 Rendering Examples

1.2 Preferred File Types

1.3 Materials List

1.4 Base Material Field of Color

2.0 Custom Design Considerations 2.1 Overall Design

2.1.1 Radii

2.2 Lap Joint Design

2.3 Vent Details

2.4 Internal Ribs

Design Preferences 2.5 Perforation Options

2.6 Internal Pressure Vents

2.7 Lightpipes

3.0 Tooling Design

3.1 Tooling Materials

3.2 Tooled in Logos 3.3 Undercuts and Action

Undercut detail, .150 wall

3.4 Label Recess Design Criteria

3.5 Tooling Finish : Clear & TintedParts

4.0 Hardware Considerations

4.1 Ball Stud Specs

4.2 Insert Specifications

Short Inserts

Regular Inserts

Flanged Inserts 4.3 Boss Design for Flanged Inserts

4.4 Captive Screws

5.0 Finish Considerations

5.1 Paint Finish

5.2 Min/Max Chips

5.3 Paint Lines for Two-Tone Parts 5.4 Logo Artwork Design

6.0 EMI Shielding

6.1 Nickel Coating

6.2 Gasketing

7.0 Quality Assurance

7.1 CMM 7.2 Exterior Finish Control See 5.2 Min/Max Chips


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1.0 Design Basics Design

Giving your product every chance at success is, no doubt, your top priority.We'll get your product to market faster and with higher quality (because ofthe design and details) than other manufacturers. And we don't have to tellyou what that means: the sooner your product is on the market, the moreunits you can sell. At ThermoFab, we feel the same way, which is why we'renot only equipped to work with designers you bring to the table, but we'realso equipped with design experts and engineers in-house who can turnyour product dreams into reality.

Details

As the old saying goes, the devil is in the details, and the same holds truefor plastic enclosures that house sensitive medical, computer, electrical, andother industrial products. We've developed a proprietary process that offersclose tolerances, tight specifications, and sharp detail.

Speed

As you know, the time-to-market (TTM) interval (the time needed todevelop a new product) is critical to success. But reducing TTM won't beenough, ifit means the product's integrity is affected due to shortcuts oruntested processes.


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1.0 Design Basics - Continued

Work with a manufacturer that has in house designers or anexperienced designer. But don't overdesign. Remember, plastic isflexible. It moves. Keep in mind "tolerance stack-up": how manycomponents are stacking up and mating together? Work with an

industrial designer or engineer who has designed for plasticnot alldesigners have.

Keep the end phase in sight, even when you're in the prototypephase. We believe the prototype should provide a solid idea of what the

final manufactured product will look like. To accomplish this, you need tothink about your brand, colors, the location of labels, etc. now.

Use production-grade plastic. Production-grade plastics will provide abetter idea of how the final product will look and work. It's definitelyworth the investment to have a working prototype in the end, the keyword being "working." At the same time, be mindful of where you cansave dollars. For example, you might be able to use CNC machining andsoft tooling to create the initial production pieces.


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1.1 Rendering Examples

Initial Design Rendering Concepts are created for Phase I of thedesign process.

Usually 2-3 Concept Views are Created First (Images 1-3).

The Initial Renderings are reviewed and details are chosen that arepreferred.

The process narrows down the design elements so that a final look

is created (Image 4).

Images 1-3

Image 4


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Solid Model File Formats:

SolidWorks Native Files IGES

Parasolid (.XT Files)

ProEngineer Native Files

2D Drawing File Formats:

SolidWorks .DWG Files

DXF

DWG

PDF

1.2 Preferred File Types


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1.3 Materials List

Materials:

Flame-retardant ABS

Starex

KYDEX sheet

Acrylic/PVC

ABS

PVC

GE Lexan

Bayer Polycarbonate Acrylics

High impact polystyrene (HIPS)

Typical Products:

Custom Enclosure Equipment Housings

Shrouds

Covers

Bases

Bezels


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1.4 Base Material Field of Color

Image 1 is a photo of rawmaterial samples.

Base material color is closely

matched to final paint color. Image 2 shows silver finish

paint on base grey material.

Below are examples of base colors:

Black

Grey

Natural

White

Image 1Raw Material Samples

Image 2

Finish Painted Part


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2.0 Custom Design Considerations

You may find yourself saying: Ive never designed for

ThermoFab before where do I start?

There are many details that must be considered duringthe design and engineering phases.

The details in this section will assist you as you put thefinishing touches on your 3D Model Files.


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2.1 Overall Design

Helping You Go From Ideas To Implementation

With over 30 years experience, ThermoFab knowswhats required to take your design files and transformthem into a product that your clients want to buy.

In-house design, tooling, painting, EMI shielding, andother custom processes provide a level of detail andquality that other companies cant achieve.

A dedicated team of experts works closely with product

designers to review your designs and provide thetooling you need to ensure manufacturability. Ourexperienced in-house manufacturing staff then takesthe lead to produce your custom plastic enclosuresexactly to your specifications.

From design review to tooling to manufacturing topainting and shielding and even assembly, we have thequality systems in place to ensure your finished productdelivers.


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2.1.1 Radii

MaintainConstant wallthickness if

possible

.125 wallrecommended

Exterior R .020MIN


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Image 1: Shows PreferableLap Joint Design

o Minimum Wall is .120

o Minimum Draft @ JointInterface= 3 Degrees

Image 2:

o Not recommendedUndercut design

2.2 Lap Joint Design

Preferred Lap J oint Design Minimum WallThickness is .120Preferred 3 deg. Minimum Draft at J oint

Interface.

Image 2

Design Not Recommended: UndercutAround Part Traps Inner Core.

Image 1


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2.3 Vent Details

Vent details not only handleneeded airflow

requirements, but alsocreate design style as well.

Simple to intricate designlines can be created with aventing detail.

Images to the left showrectangular, oval, and even

cylindrical vent detail.


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Image 1: Showing theunderside ribbing structureadded to a product design.

The base of the rib shouldbe no more than 2/3 of thenominal wall in thickness.

The top of the rib shouldbe no less than .035 thick.

Image 2: The greenhighlighted walls showrecommended minimum degree of draft per side fortall ribs. Preferable 1degree draft per side.

2.4 Internal Ribs

Image 1

Image 2


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2.5 Perforation Options

Image 1 & Image 2:

Aluminum Hexperforationbacking usedin bezel design

Image 3 & Image 4:

1/8 PVC

Roundperforationused in bezeldesign

Image I

Image 1

Image 2

Image 3

Image 4


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2.6 Internal Pressure Vents

At ThermoFab, one of the keys to our proprietary process isthat we're creating a core that creates a part that hassignificant detail molded in.

Our proprietary process allows for an extra 40 to 50 percentmore detail than traditional thermoforming. In fact, thedetails are so precise, our thermoformed plastic enclosureslook injection molded. Here's an example that illustrates ourstrong commitment to the tooling process.

Image 1: The interior view of the part below shows thepressure vent indentations that make the detail possible inthe process.

Image 1


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2.7 Lightpipes

Here are some customlightpipe designs.

Custom lightpipes areformed and created withspecific diffusing propertiesas the project requires.

Back-lighting the lightpipecreates additional visualhighlight.


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3.0 Tooling Design

Temperature controlled aluminum tooling

Maintains maximum control over theentire tooling process

Successful tooling requires: A skilled craftsman who considers the

plastic, shrink, and aluminum toolingnecessary to create the desired partsfrom your 3D files

The ability to make necessarychanges and refinements quickly soyour project stays on deadline andyour product performs as intended

Features: Blind venting

Louvers

Undercuts

Molded logos


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3.1 Tooling Materials

ALUMINUM

STEEL

HIGH TEMP REN (Soft

Tooling for PrototypeOnly)


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3.2 Tooled in Logos

Logos are tooled in precisely.

The details are amazing and are

often highlighted with additionalfinishing options, such as paint,texture, appliqus, or lightpipes.


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3.3 Undercuts and Action

Image 1 shows the modelfile, which was a uniquepart. The color was tintedand two tone. The handledesign and pivot point were

handled with undercutaction designed into thetooling.

Image 2 shows theintegrated door with theundercut handle at the topin the completed assembly.

Image 1

Image 2


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3.4 Label Recess Design Criteria

Labels work best in a thermoformed piece when they are recessed

into the design itself.

Recessing provides a finished look that cannot be achieved byaffixing the label in any other way.

Recessing prevents the label from getting torn off when shipped orduring everyday use.

Image 1 shows the finished design and the placement of the label atthe top.

Image 2 shows the actual part.

Image 1

Image 2


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3.4 Label Recess Design Criteria - Continued

Images 3 and 4show the designdetails associatedwith the labelrecess

Recess Should be.005-.010 Deeper

than LabelThickness

Recommend .005-

.010 Larger allaround

Image 3

Image 4


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3.5 Tooling Finish - Clear and Tinted Parts

Recommend A-2 Finish for Clear andTinted Parts

Tooling Finish Polish Guide Examples:Polish GuideA 1 GRADE #3 DIAMOND BUFF

A 2 GRADE #6 DIAMOND BUFF

A 3 GRADE #15 DIAMOND BUFF

B 1 600 GRIT PAPERB 2 400 GRIP PAPER

B 3 320 GRIP PAPER

C 1 600 STONE C - 2 400 STONE

C 3 320 STONE

D 1 DRY BLAST GLASS BEAD #11

D 2 DRY BLAST #240 OXIDE

D 3 DRY BLAST #24 OXIDE


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4.0 Hardware Considerations

Design attachment detail question

examples are:

How will your products attach tothe inner framework chassis?

How will the structure be laid

out in the design detail?

How will your bezel front attachto the metal frame?

Does the product have to hingeopen? Lock? Have specificaccess requirements?


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Image 1 Fastening ClipTop View

Image 2- Fastening ClipSide View

Image 3 Ball Lock Stud

Detail

4.1 Ball Stud Specs

Image 1 & 2

Image 3


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4.2 Insert Specifications

Insert specifications and bossdesign are critical elements to

designing your plastic enclosure.

How will it attach to thechassis?

How best to attach the exteriorplastic to the frame?

How do I streamline the

attachment hardware whenhandling multiple components?


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The chart below works bestwhen designing for shortinserts.

4.2 Short Inserts


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The chart below works bestwhen designing for regularinserts.

4.2 Regular Inserts


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The chart below works wellwhen designing for flangedinserts.

4.2 Flanged Inserts


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The chart andboss designdiagram works

best whendesigning thelayout for theflanged insert

sizes listed.

For unflangedinserts,eliminate the

counter boreportion of thehole.

4.3 Boss Design for Flanged Inserts


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Screws thread through minor dia. hole in plastic

Outer counterbore for screw head

Inner counterbore for threaded portion of screwshank

4.4 Captive Screws


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5.0 Finish Considerations

The Right Color Makes Your Product Shine

ThermoFab executes all painting in-house to ensure

maximum control over color, gloss, and texture. For

the exterior color, we can color match using your color

sample chip or specification. To ensure the right color

is applied every time, ThermoFab uses Dupont

Spectramaster.


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5.1 Paint Finish

Detail and Color letyour products stand out

from the crowd!

EMI/RFI spray shielding solutions

Skys-the-limit design options

Incredible detailing

Custom paint processes

Unique detail


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5.2 Min/Max Chips

Min/Max Paint Chips areused for color/texture/glosslevel criteria.

Each chip is divided in half.One half is the minimum;the other half is themaximum.

These chips are kept byThermoFab and the clientso that each lot falls withinthe acceptable min/maxrange.


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.03 wide by .03 deep groove at paint line for

masking.

5.3 Paint Lines for Two-Tone Parts


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5.4 Logo Artwork Design

Logo Design: Branding, Branding, andBranding!

Line art is required for traditional screenprinting. However, we have a machine that canprint photographic images onto components,

but the part must be no more than 2" thick. Gradients are not recommended because eachcolor is screened individually onto apart. However, dot patterns in the screens maybe used to mimic the look of a gradient. Theresult is a pixilated image that is best viewed

from afar. Vector Artwork: If you have vector-based

artwork from any of the file types listed below,the DPI doesn't matter. But if it is raster-based,a higher DPI will produce a better look.

Preferred Files: Adobe Illustrator, Photoshop,Acrobat, and Distiller (.pdf, .eps, .ai, .ps, .psd),as well as AutoCad (.dwg, .dxf), Corel Draw(.cdr), and Corel Photo (.cpt). (We do not

accept JPEGs, GIFs, or bitmaps.)


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6.0 EMI Shielding

EMI shielding protects anyelectronic products inside yourcustom thermoformedenclosures from electromagnetic

interference (EMI).

ThermoFabs certified techniqueinvolves applying Electrodag

440, a conductive stable nickelcoating. We always perform EMIshielding in-house to ensureprotection of your sensitive

components and reduce time tomarket (TTM).


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Green indicates shielded surfaces

Protects electronic products inside your customthermoformed enclosures from electromagnetic interference

(EMI); you will need EMI shielding.

Certified for Electrodag 440, a conductive stable nickelcoating

6.1 Nickel Coating


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6.2 Gasketing

Gasketing can be added to the interior designof the part. EMI gasketing gives additional

levels of protection when required. See

examples below.

Knitted Wire Mesh EMI/RFI Shielding Tape is a double-layered

strip of knitted wire mesh. It provides effective electromagnetic and

radio frequency interference (EMI/RFI) shielding for electrical and electronic

cable assemblies.

Metallized Fabric Shielding Gasketing is a combination of a

metallized, woven nylon cover over a foam core. It provides superior EMI/RFI

shielding.

Wire Mesh Over Elastomer Core Gasketing provides effective EMI/RFI

shielding and environmental protection. With two layers of mesh over

an elastomer, the elastomer under pressure protrudes through the

mesh to give sealing protection.


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7.0 Quality Assurance

Quality You Can Count On

ThermoFab is committed tostaying ahead of the competitionand helping you do the same.

Quality is not just a department; itis an ongoing commitment tocontrol, improvement, and

innovation.

From tooling to final delivery,ThermoFab has inspections

throughout the process to ensurethat the product you bring tomarket exceeds your expectationsfor detail, craftsmanship, andperformance.


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7.1 CMM

We know that you are workingon a tight time to market, sofrom the moment you contactus, we respond promptly and

clearly to your questions andrequests.

When we review your files, we

will not commit tomanufacturing your productunless we know we can delivera quality custom plasticenclosure within your tolerancesand specifications.


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7.2 Exterior Finish Control

Paint Color Min/Max Chips forProcess Control

Logos

Silk-screening

Final Inspection


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Just A Few Satisfied Customers


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76 Walker Road, Shirley, Massachusetts 01464 USAT 978.425.2311 F 978.425.2305 www.thermofab.com

Custom Plastic Enclosures. Revolutionary Process.

Thank You!

Documents

ThermoFab Design Guide