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Production Files, Prototype Fitment and the Design Report

Course 3 · Module 6 Suggested time: about 3 hours + separate time for printing/assembling the prototype Format: Capstone — prepare print files, build/check a prototype, test with firmware, then submit a Design Report to close the course

Lab · Design report · ← Table of Contents · ← M05

Objectives (Learning Outcomes)

Section titled “Objectives (Learning Outcomes)”

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

  1. Prepare production files (STL / STEP) from Blender
  2. Build / check a prototype and its fitment against a real circuit or board
  3. Test alongside firmware and edge AI (including host / web-app/ evidence)
  4. Summarise the results in a Design Report with next-iteration recommendations

Key phrase M06 = closing the loop from concept to something you can hold — complete files with no assembly/test evidence still do not count as finishing the course.

Read alongside this chapter

Section titled “Read alongside this chapter”
Document Use when
M05 — Digital Validation The Top 3 fixes · Ready/Not ready decision before printing
M04 — GLB / Twin The Twin-ready file that must be delivered alongside the STL
M01 — Scale & block The mm units · the clearance you locked in
3D Print Toolbox (Blender Manual) Checking non-manifold geometry / Make Manifold
STL export (Blender Manual latest) File → Export → STL (menu varies by version)
Protolabs — Enclosure for 3D printing Walls · clearance · bosses
All About Circuits — enclosure steps The order of steps before printing
3DDFM enclosure guide Fitment / assembly mindset
Bitstream Studio Keeping the Twin alongside during testing
TESAIoT_Hackathon HEX · Flasher · web-app/ex05 · ex06
TESAIoT Developer Hub Firmware examples when testing inside the box
Design report template The main deliverable form
M05 pre-prototype checklist Attach it to the report

1. Capstone Deliverables (Course 3 Package)

Section titled “1. Capstone Deliverables (Course 3 Package)”
Deliverable Required? Notes
Project .blend Yes The final version after fixes from M05
Twin-ready .glb Yes From M04/M05
Print file STL (≥ 1 part) Yes Lid and/or base — separate files if printed separately
Design report Yes Every main section filled in
M05 pre-prototype checklist Yes Attached, or summarised in the report
Fitment / demo photos or clip Strongly recommended The board inside the box · ports · sensors
STEP (or another CAD exchange format) Optional If you have a conversion tool for CNC 
Concept (M01) → Detail + PBR (M02) → Motion (M03)
    → GLB / Twin (M04) → Validate (M05) → Print + Report (M06)

2. Production Files — STL (and Optional STEP)

Section titled “2. Production Files — STL (and Optional STEP)”

2.1 When to use which format

Section titled “2.1 When to use which format”
Format Use when
STL General 3D printing (FDM/SLA, depending on the round) — the lab’s main path
STEP Passing on to CAD / CNC — usually needs a conversion tool or a paired CAD model, not a single button in every version of Blender

2.2 Mesh checks before export

Section titled “2.2 Mesh checks before export”

A printer needs a watertight / manifold mesh — each edge connects to about 2 faces, with no unintended holes.

Use the 3D Print Toolbox add-on:

  1. Edit → Preferences → Add-ons → search for 3D Print Toolbox → enable it
  2. In the 3D Viewport press N → the 3D-Print tab
  3. Select the part → Check All
  4. Fix reported issues, especially Non-manifold
  5. Use Make Manifold as a starting point, then check again by eye

Additional help:

  • Ctrl+A → Scale before exporting
  • Edit Mode → Merge by Distance if there are duplicate points
  • Shift+N Recalculate Normals Outside

Walls should still be about ≥ 2 mm, per printed-enclosure guidance (Protolabs)

2.3 Export STL — step by step

Section titled “2.3 Export STL — step by step”
  1. Separate the objects you will print (Enclosure_base, Enclosure_lid)
  2. Select one part (or use batch export, depending on the version)
  3. File → Export → STL
  4. Turn on roughly: Selection Only · Apply Modifiers (if any modifiers remain)
  5. Give it a clear name, for example enclosure_base.stl, enclosure_lid.stl
  6. Import it into a slicer (e.g. Cura) and check the mm size again before printing

2.4 If you cannot print yet

Section titled “2.4 If you cannot print yet”

You can still submit the STL + report by stating in the Design Report:

  • The printer/service you plan to use
  • The intended material (e.g. PLA)
  • What you will check once you have the real part

Do not leave the fitment section blank — use a mock assembly with the board + a temporary paper/plastic box, or measure the openings from the model against the real board and photograph the evidence.

3. Prototype Build and Fitment

Section titled “3. Prototype Build and Fitment”

3.1 Fitment checklist (with real board)

Section titled “3.1 Fitment checklist (with real board)”
Check Pass means
PCB inserts without forcing No need to pry it in hard enough to risk breaking a pin
Ports align A USB/cable can plug in, or it’s clearly visible that it can
Sensor openings align The opening lines up with the chip/vent as designed
Lid closes reasonably Not so loose it falls off, and doesn’t need to be forced shut
Fasteners / bosses (if any) A screw or fastening plan fits per the design
Internal cables There is routing space allowed for in M01

Assembly/clearance concepts: 3DDFM enclosure guide, All About Circuits enclosure steps

3.2 Photograph evidence

Section titled “3.2 Photograph evidence”

Take photos of at least:

  1. The printed part, or the STL in the slicer (if not yet printed)
  2. The board sitting in the base (or held up for a size comparison)
  3. The lid assembled / the port openings
  4. (Recommended) the device working inside the box

4. Test with Firmware and Edge AI

Section titled “4. Test with Firmware and Edge AI”

After placing the board in the box (or comparing it against it):

Test How Evidence
Power / LED / button Basic firmware still responds A photo or short clip
Sensors still read Temperature / IMU etc. are not so blocked by the box that the value dies The Studio or web-app
Twin still useful Open the GLB alongside the real thing A screenshot
Section titled “4.1 Recommended host evidence”
  1. Bitstream Studio — Link + telemetry
  2. Hackathon web-app/ — ex05 or ex06 (TESAIoT_Hackathon)
  3. If using a HEX from the lab pack — state the version in the report

Note whether sensors inside the box still read correctly or are degraded — this is an important lesson of a real enclosure.

5. Design Report

Section titled “5. Design Report”

Copy and fill in design-report-template.md

The required sections, in summary:

  1. Project information
  2. Design objectives
  3. Concept → Final summary
  4. Scale and materials
  5. Twin integration
  6. Digital validation and issues found (drawn from M05)
  7. Prototype / fitment test results
  8. Next-iteration recommendations, at least 3
  9. File appendix

A good report can be read and reproduced — not just pretty words with no scale numbers or file names.

6. Rubric (Minimum Pass)

Section titled “6. Rubric (Minimum Pass)”
Criterion Required
.blend + .glb + STL (≥1) Yes
Design report complete Yes
M05 checklist attached or summarized Yes
Scale / units discussed honestly Yes
Fitment or clear print plan + measurement evidence Yes
Firmware / Twin / web-app considered in testing section Yes
Next-iteration recommendations ≥ 3 Yes
No secrets (Wi‑Fi / passwords) in submitted files Yes

Extension work (optional): a full print of lid+base · successful assembly with the board · sensor streaming inside the box via ex05/ex06 · a STEP file for further work

7. After Course 3

Section titled “7. After Course 3”

You have taken a product from concept → model → Twin → checklist → prototype, and connected it with firmware/edge AI data at lab level.

Next direction Where to go
Deeper firmware Course 1
Twin / telemetry / MQTT Course 2
Real production / injection moulding DFM and manufacturers — the Twin in this course is a practice field
Reference models/assets ternion-3d-assets-free

Next Steps

Section titled “Next Steps”
  1. Do the lab — submit the package that closes the course
  2. Fill in design-report-template.md
  3. Attach the checklist from M05

References and Further Reading

Section titled “References and Further Reading”
  1. 3D Print Toolbox
  2. Blender import/export overview
  3. Protolabs enclosure for 3D printing
  4. All About Circuits — 3D-printed electronics enclosure
  5. 3DDFM electronic enclosure guide
  6. Bitstream Studio
  7. TESAIoT_Hackathon
  8. TESAIoT Developer Hub
  9. ternion-3d-assets-free
  10. Course 3 TOC · Course 1 · Course 2

Check your understanding

Section titled “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

Section titled “Lab”

Continue hands-on at Capstone lab: a prototype package and Design Report

Lab · Design report · ← TOC · ← M05

Review questions

Answer on your own first, then open the answer.

  1. เครื่องพิมพ์ 3D ต้องการ mesh แบบใด (Objective 1)

    1. normals ชี้เข้าด้านใน
    2. watertight / manifold
    3. มี n-gon มาก ๆ
    4. Scale ไม่เท่ากับ 1
    Show answer

    Answer: B. watertight / manifold

    หัวข้อ 2.2 Mesh checks before export

  2. เกณฑ์ “Lid closes reasonably” ในตาราง fitment หมายถึงข้อใด (Objective 2)

    1. ฝาปิดได้โดยต้องใช้กาว
    2. ฝาปิดสนิทจนเปิดไม่ได้
    3. ฝาไม่จำเป็นต้องปิด
    4. ไม่หลวมจนหลุดง่าย และไม่ต้องเคาะแรง
    Show answer

    Answer: D. ไม่หลวมจนหลุดง่าย และไม่ต้องเคาะแรง

    ตาราง 3.1 Fitment checklist

  3. Design Report ต้องมีข้อเสนอแนะรอบถัดไปอย่างน้อยกี่ข้อ (Objective 3)

    1. ไม่กำหนด
    2. 3 ข้อ
    3. 1 ข้อ
    4. 5 ข้อ
    Show answer

    Answer: B. 3 ข้อ

    หัวข้อ 5 Design Report ข้อ 8 และตาราง Rubric

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.

"Production Files, Prototype Fitment and the Design Report" 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: "ไฟล์ผลิต ต้นแบบ fitment และ Design Report" 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/m06-prototyping/l01-prototyping-final-project/

This lesson adapts the source below; keep its credit too.
https://github.com/drsanti/TESAIoT-Courses/blob/287c21814ba8c75f693136616dcd270349a15966/C3/M06/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

TESA Open Knowledge · © 2026 สมาคมสมองกลฝังตัวไทย (TESA) · CC BY-NC 4.0

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