Week 5: 3D Scanning and Printing

Assignment Overview

This week I learned 3D printing and 3D scanning. I designed and printed a gearbox. I also made a 3D model of a frog figure using photos.

Date: February 18–25, 2026 Status: ✅ Completed

📋 Assignment Requirements

Group Assignment

✅ Test the design rules for your 3D printer

  • [x] Test minimum wall thickness
  • [x] Test minimum hole size
  • [x] Test overhang angles
  • [x] Test bridge length
  • [x] Record printer settings and results
  • [x] Share results on the group work page

Individual Assignment

✅ Design and 3D print an object that cannot be made by cutting or machining

  • [x] Designed a gearbox in Fusion 360 using the SpurGear script
  • [x] The gears are inside a box — impossible to machine
  • [x] Printed twice (PETG first, then PLA)

✅ 3D scan an object

  • [x] Took 4 photos of a frog figure
  • [x] Uploaded to Hitem3D (web AI service)
  • [x] Got a 3D mesh (STL file)

🎯 What I Made This Week

3D Printed Object — Gearbox

I made a gearbox. It has gears inside a box. The gears cannot be put in after printing — everything is printed as one piece. You cannot make this with cutting tools.

Size: 62 × 25.99 × 30 mm Material: PLA Matte grey (2nd print) Printer: Bambu Lab P2S

3D Scanned Object — Frog Figure

I used Hitem3D to make a 3D model from photos. I took photos from 4 directions and uploaded them. The service made a 3D mesh automatically.

🛠️ Group Assignment: Testing Design Rules

What Are Design Rules?

Design rules show the limits of a 3D printer. They tell us how thin a wall can be, how small a hole can be, and how far a part can stick out without support. Knowing these limits helps us make better designs.

Test Piece

We printed a test piece using white PLA on the Bambu Lab P2S. It has overhang tests, wall thickness tests, hole size tests, and bridge tests.

Design Rules Test Piece Test piece (white PLA) — overhang angles, wall thickness, hole sizes, and bridges

Test Piece — Front and Back Both sides of the test piece — checked with team members

Key Results

We used two printers: Bambu Lab P2S (256×256×256 mm) and Bambu Lab H2S (340×320×340 mm). Both used white PLA matte filament.

Test Result
Material PLA matte (white)
Printers Bambu Lab P2S / H2S

Both printers gave similar results. Auto flow correction helped keep the quality high.

📎 For full details → Group Work Page

🖨️ Individual Assignment 1: 3D Printing a Gearbox

Design Concept

I made a gearbox for my Smart Reptile Habitat System. The habitat needs a part to open and close the ventilation window. The space inside the control box is small. Metal parts could rust in a humid place. A snap-fit part could break. So I printed everything as one solid piece.

Why this cannot be made subtractively:

The gears are inside a closed box. You cannot reach inside with a cutting tool. The only way to make this shape is to print it layer by layer from the inside out.

Step 1: CAD Design in Fusion 360

Using the SpurGear Script

Fusion 360 has built-in scripts for making complex shapes. I used the SpurGear script (Python, v2.0) to make gear shapes automatically.

Scripts and Add-Ins Menu Fusion 360 → UTILITIES → ADD-INS → Scripts and Add-Ins

SpurGear Script Selected Selecting the SpurGear script (v2.0, Python)

I first ran the script with test numbers to learn how it works.

SpurGear Parameters SpurGear parameters — the numbers shown are for testing; the real gear uses different values

Final gear parameters:

Parameter Value
Module 1
Pressure Angle 20°
Number of Teeth 24
Thickness 2 mm
Hole Diameter 2 mm
Pitch Diameter 24 mm

Generated Gear Sketch Generated gear (top view, 24 teeth) — very easy to make with the script

I first tried to draw gear teeth by hand. It was very hard. Then I found the SpurGear script and it was much easier. I will always check for scripts before drawing complex shapes.

Final Gearbox Model

After making the gears, I built the box around them in Fusion 360.

Gearbox — Front View Finished gearbox — front view, gear train inside the box

Gearbox — Perspective View Finished gearbox — side view, gear train visible

Step 2: Slicing in Bambu Lab Studio

Fusion 360 can export files that Bambu Lab Studio reads directly. No extra steps needed.

Bambu Lab Studio — Slicer Setup Model loaded in Bambu Lab Studio. Support structures added automatically (tree auto, 30° threshold). Size: 62 × 25.99 × 30 mm

Bambu Lab Studio — Support Preview Preview after slicing — complex support shapes that would be impossible to build by hand

Slicer settings:

Setting Value
Printer Bambu Lab P2S
Nozzle diameter 0.4 mm
Material (1st print) PETG Translucent
Material (2nd print) PLA Matte grey
Layer height 0.20 mm Standard @BBL P2S
Support tree(auto), threshold 30°
Nozzle temperature 245°C

Step 3: Printing on Bambu Lab P2S

I sent the file from Bambu Lab Studio to the printer. Printing started automatically.

Printing in Progress Bambu Lab P2S printing — you can see the support and model through the side window

Printer Touch Panel Touch panel: GEAR / 33% done / Layer 44 of 150 / 245°C

Printing video — fast and accurate. The print finished in about 1 hour.

Step 4: Results

1st Print — PETG Translucent

1st Print Result 1st print — a lot of support material at the bottom

Support Removal Removing PETG supports with a knife — very hard and slow

Problem: PETG supports were very hard to remove. It took a long time and left marks.

2nd Print — PLA Matte Grey

Final Result — PLA 2nd print (PLA grey) — box and lid separated, gear train visible. Supports came off easily.

After removing supports, the gears moved as planned.

Result: PLA supports came off much more easily than PETG. The gears worked well. I prefer PLA for parts like this.

📷 Individual Assignment 2: 3D Scanning

Object — Frog Figure

I chose a green frog figure on a yellow pole stand. It has a round shape with many surface details. This makes it a good test for 3D scanning.

Frog Figure — Back Scan subject: green frog figure (back view) — on yellow pole stand

Frog Figure — Front Front view — round eyes, red mouth, soft toy style

Frog Figure — Side Side view

Frog Figure — Angled Front Front angle view

Step 1: Preparing Photos

I took photos from 4 directions. Then I removed the background to get a clean image. This helps the AI focus on the figure shape.

Front Back Left Right

4 photos with background removed (front / back / left / right)

Step 2: Setting Up Hitem3D

I used Hitem3D — a web service that makes a 3D model from photos using AI.

Hitem3D — Website Hitem3D website — "Multi-view to 3D" mode, model v2.0, resolution 1536P²pro

Settings:

Setting Value
Mode Multi-view to 3D
Model Version v2.0
Resolution 1536P²pro
Generate Type Geometry

Step 3: Uploading the 4 Photos

I uploaded the front, back, left, and right photos.

Hitem3D — Photos Uploaded 4 photos uploaded — ready to generate

Step 4: Generating the 3D Model

The service makes the 3D mesh in the cloud. Version 2.0 takes longer but gives better quality.

Hitem3D — Generating Generating geometry (2%) — "V2.0 may take longer. Thank you for your patience."

Step 5: Result

The service made a 3D mesh of the frog. The model has about 1,000,000 vertices and 2,000,000 faces. I could download it as an STL file.

Hitem3D — 3D Model Result Finished 3D model — Vertices: 999,837 / Faces: 1,999,874 / Model v2.0 / 1536P²pro

The shape of the frog looks very close to the real figure. No extra editing was needed.

📦 Design Files

File Description
GEAR.f3d Fusion 360 gearbox design
GEAR.stl STL for 3D printing
GEAR.3mf Bambu Lab Studio project file
hitem3d.stl Hitem3D scan result — not in repository (97 MB)

🔗 Connection to Final Project

This week's work helps my Smart Reptile Habitat System:

From 3D printing: - The gearbox will open and close the ventilation window in the habitat - One-piece printing is strong against moisture — good for a humid terrarium - Custom parts fit perfectly inside the control box

From 3D scanning: - I can scan existing parts and use them in CAD design - Organic shapes like decorative parts can be digitized and changed

🔧 Problems and Solutions

Problem 1: Drawing Gears by Hand Was Too Hard

What Happened: I tried to draw gear teeth in Fusion 360 sketch mode. The shape was very complex.

Why It Happened: Gear teeth need exact curves. It is very hard to draw them by hand.

How I Solved It: I found the SpurGear script (UTILITIES → ADD-INS → Scripts and Add-Ins). It makes a perfect gear from numbers in seconds.

What I Learned: Always check for built-in scripts before drawing complex shapes. Fusion 360 has many useful tools.

Problem 2: PETG Supports Were Hard to Remove

What Happened: After the first print with PETG, the support material was very hard to remove. It left marks on the surface.

Why It Happened: PETG sticks to itself more than PLA. The support bonds strongly to the model.

How I Solved It: I printed again with PLA Matte grey. PLA supports come off much more easily.

What I Learned: For parts with many supports, PLA is better than PETG. Use PETG when you need flexibility or chemical resistance.

✅ Evaluation Checklist

Group Assignment

✅ Tested 3D printer design rules

  • [x] Test piece printed (white PLA, Bambu Lab P2S)
  • [x] Overhang, wall thickness, hole size, bridge length tested
  • [x] Results on group work page

Individual Assignment

✅ Designed and printed an object with additive-only features

  • [x] Gearbox designed in Fusion 360 (SpurGear script + housing)
  • [x] Gear train inside a box — cannot be made subtractively
  • [x] Printed with PETG (1st) and PLA (2nd)
  • [x] Process shown with photos and video

✅ 3D scanned an object

  • [x] Frog figure photographed from 4 directions
  • [x] Uploaded to Hitem3D (Multi-view to 3D)
  • [x] 3D mesh made (STL output)
  • [x] Process shown with screenshots

Documentation

✅ Showed process with photos

  • [x] CAD design steps
  • [x] Slicer settings and preview
  • [x] Printing process (photos + video)
  • [x] Print results (both attempts)
  • [x] Scan subject photos
  • [x] Hitem3D steps and result

✅ Design files included

  • [x] GEAR.f3d, GEAR.stl, GEAR.3mf in repository

File Management

✅ Images under 500KB

  • [x] All images compressed to 720px width

✅ Files saved to GitLab

  • [x] Pushed to repository

💭 Reflection

What Went Well

  1. SpurGear script: The script made gear design very fast. Drawing by hand was too hard.

  2. Bambu Lab workflow: The workflow from Fusion 360 to Bambu Lab Studio to the printer was very smooth.

  3. Hitem3D: I got a 3D model from just 4 photos. I did not need a real 3D scanner.

What I'd Do Differently

  1. Use PLA first, not PETG: PLA supports are much easier to remove. I will use PLA for test prints.

  2. Check for scripts first: Before drawing complex shapes, I will look for scripts or tools first.

Lessons Learned

  • 3D printing can make enclosed parts: Gears inside a box are only possible with 3D printing. This is very useful for the final project.
  • Material choice matters: PETG and PLA are very different when removing supports. Choose the right material for the job.
  • AI scanning tools work well: Hitem3D made a good 3D model from just 4 photos. This is useful when you do not have a 3D scanner.

For Next Week — Electronics Design

  • [ ] Learn circuit simulation tools (KiCad, LTspice)
  • [ ] Study EDA software for PCB design
  • [ ] Plan circuits for the habitat system sensors

📚 References

Last updated: February 25, 2026