3D Scanning and Printing

This week was all about additive manufacturing, better known as 3D printing. Unlike traditional subtractive manufacturing, where material is carved away from a solid block (like CNC milling or laser cutting), additive manufacturing builds objects layer by layer, allowing for more complex and intricate designs.

3D Scanning

What is 3D Scanning?

3D scanning is the process of capturing the shape, size, and surface details of a real-world object and converting that information into a digital 3D model.

How it works:

A 3D scanner collects data from the surface of an object using methods like:

Laser triangulation – A laser beam is projected on the object, and a sensor captures the reflected light to measure distances.
Structured light scanning – Patterns of light (like stripes or grids) are projected, and the way they deform on the object's surface is used to map its shape.
Photogrammetry – Many photos are taken from different angles, and software stitches them into a 3D model.
Time-of-flight scanning – Measures how long it takes for a light pulse to bounce back from the object to calculate distance.

Output:

The scan results in a digital file (usually STL, OBJ, or PLY), which contains a mesh — a network of tiny triangles that form the surface of the object.

Applications:

Reverse engineering (copying or modifying physical products)
Preserving historical artifacts (like scanning ancient sculptures)
Medical modeling (scanning body parts for prosthetics or surgery planning)
Quality control in manufacturing

Scanning a Samosa

For this assignment, I decided to bring some fun (and flavor!) to the world of 3D scanning by choosing a samosa as my object. Instead of scanning something typical like a figurine or a tool, I thought, “Why not scan food?”—so I set out to digitize one of India’s most iconic snacks.

Step 1: KIRI Engine App (iOS)

To begin, I used the KIRI Engine app on my iPhone, a free and user-friendly photogrammetry tool that allows users to create 3D models from photos. Photogrammetry works by analyzing multiple overlapping images of an object from different angles to reconstruct a 3D shape.

Process:

I selected Photo Mode in the app, which allows automatic photo capture.
Placed the samosa on a neutral-colored table to minimize shadows and reflections.
Scanned the samosa from all around—360° horizontally, top-down, bottom-up, and from varying side angles.

The app automatically captured about 100 photos, ensuring full surface coverage.

Once the scanning was complete, the app processed the images and generated a .OBJ file, which contains the 3D geometry and texture data of the samosa.

Step 2: Post-Processing in Blender

Although the 3D model looked impressive, it also included the surface of the table, and the samosa itself was hollow and messy inside, which wouldn’t be suitable for 3D printing. So, I imported the .OBJ file into Blender, an open-source 3D modeling and editing software.

What I did in Blender:

Removed the unwanted surface mesh (the table captured along with the samosa).
Applied the “Solidify Modifier” to give the samosa actual thickness—since photogrammetry often creates a hollow shell with no depth.
Added inner wall offset to mimic a layered or realistic inner structure.
Cleaned the mesh: Removed non-manifold edges, filled gaps, fixed normals, and ensured the model had a clean, watertight surface.
Prepared the final mesh for slicing and exporting in a format suitable for 3D printing (typically .STL or .OBJ).

Step 3: 3D Printing

With the model ready, I used a Bambu Lab Carbon 1 3D printer—a high-quality, fast, and reliable FDM printer known for multi-color and textured prints. For filament, I chose SILK Gold PLA, which added a beautiful metallic finish to the model.

Final Output:

The result was a realistic, golden samosa replica.
The texture from the scan retained fine details like bumps and folds on the surface.
While it wasn’t edible, it certainly looked delicious!

HERO SHOT

3D Printing

What is 3D Printing?

3D printing, also called additive manufacturing, is a process of creating three-dimensional physical objects from a digital model by adding material layer by layer.

It’s the opposite of subtractive manufacturing (like CNC machining), where material is removed from a solid block. In 3D printing, nothing is carved out — everything is built up from scratch.

What is Additive Manufacturing?

Additive manufacturing (AM) is the broad term used for all technologies that build 3D objects by adding material, usually in successive layers.

"Additive" = material is added to form the final shape
"Manufacturing" = it’s used to make real parts, tools, and products

Additive manufacturing includes 3D printing, but it also covers industrial-scale techniques used in aerospace, automotive, medical, and more.

How Does 3D Printing Work?

1. Create or get a 3D model

Use CAD software (like Fusion 360 or Rhino)
Or download a model from sites like Thingiverse

2. Slice the model

A slicer software (like Creality slicer, Cura or PrusaSlicer) converts the model into thin horizontal layers and creates instructions for the printer (G-code)

3. Print the object

The printer builds the object layer by layer from the bottom up using materials like plastic filament, resin, or metal powder

Types of 3D Printing Technologies

Technology	How It Works	Materials	Common Uses
FDM (Fused Deposition Modeling)	Heated nozzle melts plastic filament and deposits it layer by layer.	PLA, ABS, PETG	Prototypes, tools, enclosures, hobby models
SLA (Stereolithography)	UV light cures liquid resin in a tank layer by layer.	Photopolymer resin	Jewelry, dental models, high-detail parts
SLS (Selective Laser Sintering)	Laser fuses nylon powder layer by layer without supports.	Nylon, TPU	Functional parts, complex geometries
DMLS / SLM (Metal Printing)	Laser melts or sinters metal powders to form solid parts.	Titanium, Aluminum, Steel	Aerospace, automotive, implants
Binder Jetting	Binder is sprayed on powder layers, then cured or sintered.	Metal, ceramic, sand	Full-color models, casting molds, metal parts
Material Jetting (PolyJet)	Jets droplets of resin cured by UV light. Multi-material and multi-color.	Resin	Visual prototypes, medical models
Food 3D Printing	Similar to FDM but with edible pastes (like chocolate).	Chocolate, dough	Decorative foods, custom desserts

Group Assignment

Exploring 3D Printers in Our Lab

As a group, we dove deep into hands-on testing of the different 3D printers available in our lab to better understand how each one performs in real-world situations. We experimented with both FDM and SLA machines — focusing primarily on the Creality Ender 3 S1 Pro and the Ender 3 V3 KE for FDM, while also running high-resolution prints on an SLA printer to compare surface finish and accuracy.

Group assignment Link

What We Explored

To really understand how different 3D printers behave, we designed and printed a series of stress tests. Each test focused on a specific challenge — the kind that shows a printer’s true strengths and weaknesses.

Here’s what we dove into:

Precision Fit — Tolerances Between Parts

We printed interlocking components with small gaps to see how accurately parts could slide, snap, or rotate together. This revealed how fine the machine could resolve tight mechanical tolerances.

Unsupported Geometry — Overhangs & Bridging

We intentionally printed models with challenging angles and unsupported bridges to test how well the printer managed gravity — without falling apart or requiring support material.

Texture Check — Surface Quality at Different Speeds

From slow & careful to fast & furious, we varied print speeds to analyze how speed impacts layer visibility, surface finish, and smoothness across curved and flat areas.

First Impressions Matter — Bed Adhesion & First-Layer Quality

We observed how well prints stuck to the bed on the first try. Factors like nozzle height, bed temperature, and surface material were critical to getting a clean, solid start.

Fine Tuning — The Impact of Print Settings

Speed, cooling fans, and retraction settings were adjusted

Ender 3 S1 Pro vs Ender 3 V3 KE

Feature	Ender 3 S1 Pro	Ender 3 V3 KE
Speed	Slower (60–100 mm/s), better detail	Very fast (up to 500 mm/s), great for fast prototyping
Auto-Leveling	CR Touch – reliable with tweaks	Faster, beginner-friendly ABL
Motion System	Standard XYZ – simple but slower	CoreXZ – smoother & faster movement
UI	Basic touchscreen	Modern and easy-to-use interface
First Layer	Needs close monitoring	More consistent even on quick setups
Max Temp	300°C – supports ABS, Nylon	260°C – ideal for PLA, PETG, TPU
Cooling	Basic single fan	Dual fans – better detail & overhangs
Assembly	Semi-assembled – good for learning	Fully assembled – plug and print
Noise	Moderate	Quiet and classroom-friendly
Best For	Learning settings, strong functional prints	Fast iterations, easy prototyping

Individual Assignment

Web Shooter

Ever wanted to bring superhero tech to life? That’s exactly what I set out to do — designing a fully-functional, wearable Web Shooter using Fusion 360. This isn’t just a prop; it’s an ergonomic, spring-loaded dart launcher with a magnetic bullet, wrapped in a design that hugs your wrist like it was meant to be there.

Why This Design?

The idea was to create something mechanically interactive, wearable, and fun — a concept where form and function unite. My goal wasn’t just visual accuracy, but to design something buildable with additive manufacturing that could actually work.

Here’s what the final shooter packs:

A curved wrist-mounted base for maximum comfort and aesthetic.
A firing chamber that launches a magnetic dart when triggered.
A rotating spool rod to manage thread flow smoothly during launch.
A magnetic bullet cavity — so the dart sticks to metal like Spider-Man’s web.

The Build Process

Step-by-Step in Fusion 360

1) Sketching the Framework

I began by laying out intersecting reference lines to center the build. Using the Spline tool, I designed the base curvature to match wrist contours.

2) Extruding the Wrist Plate

That sketch was extruded into a gently arched surface, forming the ergonomic backbone of the shooter.

3) Side Mounts for Straps

Using rectangles and extrusions, I added brackets on each side for mounting Velcro straps, ensuring it can be comfortably worn.

4) Bullet Chamber Creation

The center cylinder was modeled to house the magnetic bullet. The inside was hollowed using cut-extrudes, allowing room for spring action and internal movement.

5) Thread Spool Rod

I added a cylindrical rod behind the chamber to act as a thread guide. The web string wraps around this rod, unwinding in line with the direction of the bullet's movement.

6) Magnetic Bullet Tip Slot

A circular cavity was added at the front of the bullet chamber to hold neodymium magnets — making the dart actually stick to metal surfaces.

Feature Highlights

Feature	Function
Curved Wrist Plate	Ergonomic and wearable
Launch Chamber	Holds and guides the magnetic bullet
Thread Spool Rod	Ensures thread unspools cleanly during launch
Magnetic Tip Cavity	Houses magnets for metal attachment
Strap Brackets	Secure the shooter using Velcro or custom straps

Why It Can’t Be Made Subtractively

This model is a poster child for additive manufacturing. Here's why traditional (subtractive) methods like milling, turning, or CNC would struggle:

1) Enclosed Internal Cavities

The shooter includes hidden chambers, like the bullet housing and the magnetic cavity — parts that are impossible to mill or drill unless the body is split (which would ruin the design integrity).

2) Complex Organic Curves

The wrist base is curved both longitudinally and transversely for comfort. Machining double-curved surfaces is time-consuming, tooling-intensive, and often inaccurate.

3) Interlocking/Integrated Parts

The rotating thread rod and inner launch tube are modeled as independent but aligned parts. Subtractive tools can’t easily create moving parts nested within a single body.

4) Undercuts & Internal Overhangs

The shape includes overhangs and negative spaces, especially in the launcher tube and rail mounts. These are tough or impossible to mill unless done in multiple parts and then assembled — which increases cost and complexity.

In contrast, 3D printing handles all of this effortlessly — printing layer-by-layer, even with internal features and moving parts, all in one go.

3D Printing Process

Once the design was finalized in Fusion 360, I moved to the next phase — bringing it to life using FDM 3D printing. I used Creality Print as my slicer and printed it on the Creality Ender-3 V3 KE with PLA filament.

Printer Settings

Configuration

Setting	Value
Printer	Ender-3 V3 KE (0.4mm nozzle)
Material	PLA
Layer Height	0.2 mm
Infill Density	18–20%
Shell Layers	4 top / 4 bottom
Print Speed	80 mm/s
Supports	Tree support (auto)
Print Time	~55 mins

I enabled tree supports for overhangs and used a brim for better bed adhesion.
The internal channels and curves needed proper orientation and slicing accuracy to avoid failure or weak layers.

Slicer Optimization Strategy

Orientation: I positioned the model vertically for minimal support on visible surfaces.
Support Style: Tree supports were chosen over linear to save material and improve surface quality.
Wall Loops & Patterns: Used monotonic infill and shell patterns to balance strength and finish.
Platform Adhesion: A brim was added around the base to prevent warping due to the tall, narrow stance.
G-code Preview: I analyzed the G-code to verify support placements, infill paths, and check for layer conflicts.

I enabled tree supports for overhangs and used a brim for better bed adhesion. The internal channels and curves needed proper orientation and slicing accuracy to avoid failure or weak layers.

Post-Processing & Assembly

After printing, I:

Removed supports with pliers.
Sanded rough edges for smooth movement.
Inserted magnets into the bullet cavity.
Installed the spring and locking system.
Threaded the web line onto the storage rod.

Finally, a funcional Web Shooter

The final test came good—the bullet launched smoothly, the thread unwound properly, and the magnets worked as expected!

Hero Shot

Exploration

3D Printing on Fabric

I've always been fascinated by how materials interact — so naturally, the idea of fusing 3D printed elements directly onto fabric sounded like something I had to try. Devanshi and I teamed up for this experiment with one goal: print the word “FAB” onto fabric by pausing the 3D print midway, placing the fabric on the print bed, and letting the rest of the print lock the fabric in place.

The plan seemed simple. But as I quickly learned — when it comes to mixing textiles with melted plastic — things don’t always go as expected.

Step 1: Planning the Print

I started by designing the text model — bold, flat letters that could print smoothly onto fabric. I used silk PLA for its nice finish and flexibility, and picked two fabrics to test:

One lightweight mesh-like cloth
One thicker, textured material

After slicing the file in Cura, I inserted a pause after 8 layers using a G-code command. The idea was to stop the print just before the letters were finished, lay the fabric down, and then resume the print so the filament would anchor into the material.

Step 2: First Attempt = First Fail

The printer paused exactly where I expected. I carefully placed the thick fabric on the print bed and hit "resume."

That’s when everything went wrong:

The nozzle rammed into the fabric. The printer didn’t move the Z-axis up after the pause, so it tried printing at the same height — smashing filament into the cloth instead of layering cleanly on top.
The material wasn’t suitable.

The thick fabric was too bumpy and textured, so the PLA couldn’t stick. When I tried the thinner fabric, the heat actually started melting and burning the threads — yikes.

The fabric moved.

Since I didn’t tape or pin it down, it shifted slightly, which totally threw off the alignment of the rest of the print.

What I Learned

This experiment was messy, but it taught me a lot about the balance between fabric softness and filament rigidity. Here’s what I’d do differently next time — and what you should definitely try if you're printing on fabric too:

Pick the right fabric. Stick to lightweight fabrics like mesh or silk. Avoid anything thick or textured — PLA won’t grip properly, and it might melt delicate fabrics if you're not careful.
Modify the G-code carefully. Add a command to slightly lift the Z-axis before resuming the print. This prevents the nozzle from plowing into the fabric.
Secure the fabric firmly. Use masking tape, binder clips, or a low-tack adhesive to keep the material from shifting mid-print.
Tweak the adhesion settings. Try using a brim, lower layer height, or adjusting bed temperature for better bonding between PLA and fabric.

FILES

Samosa Scanned

Web Shooter