Industrial Design Principles and a True-scale Enclosure

Companion videos

Watch on YouTube (opens in a new tab)

Software Development Process - EP02 : User Needs Thai Embedded Systems Association (TESA)

Videos by Thai Embedded Systems Association (TESA) · The whole series in the playlist AIoT Foundation

Course 3 · Module 1 Suggested time: about 2 hours — learn the concepts, set up the Blender scene (units in millimetres), then build a rough enclosure at true scale Format: a hands-on lesson — read it and follow along directly in Blender; for materials and PBR surfacing, go to M02

Lab · Checklist · ← Table of Contents · M02 →

Objectives (Learning Outcomes)

By the end of this lesson you should be able to:

Explain the principles of industrial-grade design that support real manufacturing
Work through the Concept → Block Model → Final Model sequence
Explain the Casing / Enclosure / PCB Housing workflow for smart devices
Handle basic Topology, Mesh optimization and Scale accuracy in Blender

Key phrase In M01, lock the dimensions to the hardware first, then make it beautiful — if the rough block is wrong from the start, the fixes in M02–M06 all become expensive.

Read alongside this chapter

Document	Use when
Blender Download	Installing the course’s main tool
Blender 4.5 LTS Manual — Scene Units	Setting Metric / mm / Unit Scale
Apply Scale / Transforms	Press `Ctrl+A` before measuring, beveling, or exporting
Mesh Structure	What vertex / edge / face · tris · quads · n-gons mean
Mesh Modeling intro	Telling Object Mode apart from Edit Mode
Set Origin	Setting the pivot point / the point that sits on the table
Blender Fundamentals 4.5 LTS	Official training videos (English)
INC111-2021 Blender (Thai)	Thai-language tutorial
IDSA — What is Industrial Design?	The professional definition of industrial design
All About Circuits — 3D-printed electronics enclosure	The PCB → shell → port-cutting workflow · clearances
Protolabs Network — Enclosure design for 3D printing	Walls around 2 mm · clearance around 0.5 mm
KIT_PSE84_EVAL kit guide (Infineon)	Finding documentation and design files for the board used
TESAIoT Developer Hub	Board references and firmware examples
ternion-3d-assets-free	Sample scale models for reference (not a substitute for the enclosure you design yourself)
Course 2 M03 Blender intro	3D Twin basics, if you have taken Course 2
Checklist	The form to fill in while doing the lab

1. Why Industrial Design Matters for Edge AI Devices

Industrial Design (per IDSA) is designing products that people genuinely use every day — not just “a pretty picture on screen”, but something that must be usable, manufacturable, and able to fit together with the engineering inside it.

For Edge AI / IoT devices, the enclosure must handle at least:

Topic	Why it matters
PCB size + component height (connectors, sensors)	It won’t fit, or buttons can’t be pressed
Sensor openings / USB ports	Blocked → distorted readings, or a cable can’t be plugged in
Handling / placing on a desk	Ergonomics and the origin point in the Twin
Prototype manufacturing (FDM/SLA) → later injection moulding	Wall thickness / fillets / bosses each have their own constraints
Digital Twin	Wrong scale and axes → animation / telemetry look fake

This course uses Blender because it is free, open source, and can export glTF/GLB to Bitstream Studio in M04.

Concept sketch
    → Block model (this module)
        → Detailed model + materials (M02)
            → Motion clips (M03)
                → Twin + validation (M04–M05)
                    → Print / fitment / report (M06)

2. Industrial-grade Design — Four Lenses

An “industrial-grade” product in this course means: you can answer four dimensions before getting into surface detail.

Lens	Questions to answer	Edge device example
Function	What is it used for, and in what environment?	Environmental monitoring · wearable · mounted on machinery
Form & Proportion	Is the proportion comfortable to hold? Is it balanced?	Too tall and easily tipped over · sharp edges
Material & Manufacturing	Can it really be 3D printed / injection moulded / CNC machined?	Walls too thin · cavities hard to print
User Experience	Can you open the lid, see the LED, plug in a cable without a long manual?	The USB port facing the wrong way

Read more on the professional definition: IDSA — What is Industrial Design?

For a device with a PCB inside, keep a fifth lens in mind throughout the course:

Electronics fit — every millimetre of the enclosure must refer to a real part, or a placeholder that has actually been measured.

The enclosure workflow used in prototyping industry practice (summarised from All About Circuits and Protolabs Network):

Model the internal parts first (PCB, battery, connectors)
Build the outer shell, then leave wall thickness + clearance
Cut openings for ports / LEDs / sensors
Split into a top lid and a base · prepare mounting points (bosses) in a later module
Check for interference before printing

3. Concept → Block → Final (Do Not Skip Stages)

Stage	Deliverable	Do not do yet
Concept	Rough proportions, the shape’s direction, who holds/places it and how	Shiny materials · small fillets · fine screws
Block Model	A block standing in for the PCB + battery + modules · an outer enclosure at true mm scale	Boolean port cutouts · UVs
Final Model	Production-ready detail (continues in M02+)	—

3.1 Concept (15–20 minutes on paper is enough)

Before opening Blender, answer briefly in the checklist:

How does the user hold the device (in hand / on a desk / mounted on a wall)?
Which ports must be visible from the outside?
Which sensors need an air vent / a line of sight?
Which way does the lid open (top / side)?

3.2 Block Model (the heart of M01)

Block = a rough shape at the correct size

PCB = a thin box sized width × length × thickness
Enclosure = the outer box that covers the internal parts
Leave internal spacing per the clearance guidance (see §4)

3.3 Final Model (not finished in M01)

Fillet detail, surfacing, neatly cut openings = M02 Lid-opening animation = M03

Key phrase Surface detail done too early on the wrong scale = beautiful work that a real board cannot fit into

4. Enclosure and PCB Housing Workflow

4.1 Collect real sizes first

Recommended order:

Measure the real board with vernier calipers (width × length × thickness + the tallest component’s height)
Or open the documentation for the evaluation kit used — such as the KIT_PSE84_EVAL guide and the Hardware design files from the PSOC Edge kits page
Note where each number came from in the checklist

If you do not have a board in hand yet, use the Lab placeholder in the lab (a clearly stated practice size) and swap in the real size later.

4.2 Lab clearance rules of thumb

Starting numbers, from 3D-printing enclosure guidance (Protolabs Network, All About Circuits):

Parameter	Lab default	Notes
PCB ↔ inner wall clearance	≥ 0.5 mm per side	FDM often needs more margin (up to ~1 mm)
Wall thickness	≈ 2.0 mm	The recommended minimum for a general enclosure
Headroom above the tallest component	≥ 2–3 mm	Wiring / USB connector head / print tolerance
Port openings	Allow margin around the plug	Do not cut an opening exactly the size of the connector

In M01 you do not yet need to Solidify real walls — but you must draw the outer box at least this much bigger than the PCB:

outer_X ≈ PCB_X + 2×clearance + 2×wall
outer_Y ≈ PCB_Y + 2×clearance + 2×wall
outer_Z ≈ PCB_Z_stack + top_air + bottom_air + wall(s)

A worked example (when PCB = 80 × 55 × 1.6 mm, clearance 0.5, wall 2, top air 3, bottom 1):

inner needs ≈ 81 × 56 × (1.6+3+1)
outer ≈ 81+4 × 56+4 × …  → roughly 85 × 60 × the computed height

Write down your formula and your own real numbers in the checklist — do not rely on the example numbers alone.

4.3 Interference check (manual, no physics required)

In the Blender Viewport:

Look from Orthographic top/side views (Viewports)
Switch to Wireframe (Z → Wireframe) to see the PCB inside
Confirm the PCB does not unintentionally poke through the outer wall
If objects overlap incorrectly — enlarge the outer box, or shrink the object standing in for the PCB

5. Hands-on in Blender — Scene Units and Scale Accuracy

Follow along step by step (use together with the lab)

5.1 Install and open a clean file

Install from blender.org/download (the LTS line is recommended, to match the 4.5 manual where possible)
File → New → General
Delete the default Cube if you want an empty scene: select → X → Delete

Review the UI: Interface · video Fundamentals · Thai INC111-2021

5.2 Set metric millimeters (lab recipe)

In the Scene Properties → Units panel:

Click the Scene Properties icon (the cone/scene icon on the right)
Under Units:
- Unit System = Metric
- Length = Millimeters
- Unit Scale = 0.001

Why set it to 0.001? The Blender manual explains that Unit Scale converts between Blender’s internal units and the numbers shown on the UI (Scene Units). In product modelling / 3D printing work, this setting is commonly used so that typing 80 gives a millimetre-scale length on the UI that matches engineering thinking (the same approach as community guides such as Blender for 3D Printing — Units)

Team rule: everyone on the team must use the same unit convention, and record it in the checklist — so that exporting the Twin in M04 does not end up with different files at the wrong scale.

Checking the grid (if the lines disappear because the scale is small):

Overlay → Grid · adjust the grid’s Scale so it is visible over the ~10–100 mm working range

Turn on edge measurements in Edit Mode from Overlay → Measurements (Mesh edit overlays / the overlay panel) to read edge lengths.

5.3 Create a PCB placeholder (exact dimensions)

Add → Mesh → Cube
Object Mode → the Item panel (N) → Dimensions
Enter values, for example X=80 mm, Y=55 mm, Z=1.6 mm (or your actually measured values)
Name the object: PCB_placeholder
Object → Set Origin → Origin to Geometry (Set Origin)
Move it slightly above the floor (for example, set Location Z to the base thickness you plan to design)
Object → Apply → Scale (Ctrl+A → Scale) — read the reasoning in Apply

After Apply Scale, the Scale value in the Item panel should read 1, 1, 1, while Dimensions still shows the real size.

5.4 Create the enclosure block

Add → Mesh → Cube, named Enclosure_block
Set Dimensions per the formula in §4.2
Origin to Geometry · Apply Scale
Position it so the PCB sits centred in the internal space (check with Wireframe)
(Optional) Give it a temporarily different-coloured Material, just to tell the parts apart — no real PBR needed yet

You do not need to cut port openings in M01 yet — just a block that “covers it.”

5.5 Optional: a stand-in part for a battery or a display

If the project has a battery or a display:

Add another Cube sized roughly from the datasheet
Place it in the enclosure and check it does not collide with the PCB

6. Topology and Mesh Optimization (What You Need in M01)

From Mesh Structure:

Element	Short meaning
Vertex	A point in space
Edge	A line connecting two points
Face	A surface (tri / quad / n-gon)

For a block enclosure in M01:

Do	Avoid
Use a Cube and adjust Dimensions	Unnecessary overlapping Subdivision
Keep parts as separate objects (`PCB_…`, `Enclosure_…`)	Merging everything into one blob from the start
Apply Scale after resizing	Leaving Scale at 2.0, 0.5, …
Flat shading on the box is enough	Smoothing everything until you can’t see the assembly’s edges

Optimization at the M01 level = don’t add polygons until the scale and clearance are locked down. Reducing poly count for the Twin will be revisited again before exporting in M04.

Non-manifold geometry / holes matter when doing STL in M06 — for now, if you’re using a solid Cube as a block, you don’t need to worry about the manifold-ness of a hollow shell yet.

7. Origin and Axis Habits (Prepare for Twin)

Habits worth building from M01, to make the work in M03–M04 easier:

Habit	Why
Place the Origin at the centre of the box’s base, or at an assembly corner	Easy to place on a table in the Twin
Keep the axes perpendicular to the scene’s floor	The lid rotation in M03 won’t tilt the wrong way
Give objects short, clear English names	Easy to reference in a clip list / the Twin
The whole team uses the same units	Prevents files at different scales (e.g. off by 1000x) when work is combined

Setting the origin: Object Origin

8. How M01 Feeds the Rest of Course 3

Carry forward from M01	Use in
A correctly scaled block + checklist	M02 detailed shaping / PBR
Parts already separated into lid–base in your mind	M03 open–close animation
Origin / the team’s units	M04 GLB → Bitstream Studio
The clearance you recorded	M05 validation · M06 printing and fitment

Next Steps

Do the lab step by step: Lab
Fill in scale-and-block-checklist.md
When ready, continue to M02 — Modeling, Materials, and Render

References and Further Reading

Blender (official)

Industrial design & enclosure practice

IDSA — What is Industrial Design?
Six Steps for Designing a Custom 3D Printed Electronics Enclosure (All About Circuits)
How do you design enclosures for 3D printing? (Protolabs Network)
Blender for 3D Printing — Units (an approach to Unit Scale for mm-based work)

Hardware / course portals

Check your understanding

Three short questions in quiz.yaml, one per objective of this lesson. Try answering them yourself first, then compare with the answer key and explanations in the file.

Lab

Continue hands-on at Lab: a block enclosure to hardware scale

Lab · Checklist · ← Table of Contents · M02 →

Review questions

Answer on your own first, then open the answer.

“ช่อง USB หันผิดทาง” เป็นปัญหาของเลนส์ใดในตาราง Four Lenses (Objective 1)
1. User Experience
2. Function
3. Material & Manufacturing
4. Form & Proportion
Show answer

Answer: A. User Experience

ตารางในหัวข้อ 2: เลนส์ User Experience ถามว่าเปิดฝา ดู LED เสียบสายได้โดยไม่พึ่งคู่มือยาวไหม
PCB กว้าง 80 mm, clearance 0.5 mm ต่อด้าน, ผนังหนา 2 mm ขนาดภายนอกแกน X ประมาณเท่าใด (Objective 2)
1. 84 mm
2. 90 mm
3. 85 mm
4. 81 mm
Show answer

Answer: C. 85 mm

สูตรในหัวข้อ 4.2: outer_X ≈ PCB_X + 2×clearance + 2×wall = 80 + 1 + 4 = 85 mm
ค่า Unit Scale ที่บทเรียนตั้งสำหรับงานโมเดลหน่วยมิลลิเมตร (Objective 3)
1. 0.001
2. 1.0
3. 1000
4. 0.01
Show answer

Answer: A. 0.001

หัวข้อ 5.2: Unit System = Metric, Length = Millimeters, Unit Scale = 0.001

Cite this lesson

If you teach from this lesson or reuse it in slides or documents, credit it with the text below. If you changed it, add (adapted) after the title.

"Industrial Design Principles and a True-scale Enclosure" from TESA Open Knowledge by the Thai Embedded Systems Association (TESA), https://github.com/tesaiot/tesa-qualification-program, licensed under CC BY-NC 4.0

Thai attribution: "หลักออกแบบเชิงอุตสาหกรรมและกล่องหุ้มตามสเกลจริง" จาก TESA Open Knowledge โดยสมาคมสมองกลฝังตัวไทย (Thai Embedded Systems Association: TESA) https://github.com/tesaiot/tesa-qualification-program สัญญาอนุญาต CC BY-NC 4.0

Lesson link: https://tesaiot.github.io/tesa-qualification-program/en/courses/product-design/m01-design-fundamentals/l01-industrial-design-fundamentals/

This lesson adapts the source below; keep its credit too.
https://github.com/drsanti/TESAIoT-Courses/blob/287c21814ba8c75f693136616dcd270349a15966/C3/M01/README.md · Original content by Asst. Prof. Dr. Santi Nuratch (ผศ.ดร.สันติ นุราช), KMUTT. Course 3 (C3/) of drsanti/TESAIoT-Courses. TESA funded the work and holds the rights; published here under CC BY-NC 4.0. The upstream repository carries no licence file. Text kept faithful; structure, front matter, quizzes and notes added by TESA Open Knowledge.

Full guide: how to cite TESA

Content is licensed CC BY-NC 4.0. Reuse it non-commercially and credit the Thai Embedded Systems Association (TESA) every time. · How to cite TESA