Week 5: 3D Scanning and Printing

In this week, we analyze the fundamentals of 3D scanning and 3D printing, study different printer models and materials available in our lab, and examine how G-code controls the additive manufacturing process.

Additive Manufacturing

According to the group's 3D printing page.

3D printing, also known as additive manufacturing, is a process of creating three-dimensional objects from a digital file by depositing material layer by layer.

How It Works

  • 3D model is created in CAD software.
  • The model is sliced into layers.
  • The slicer generates G-CODE.
  • The printer executes movements and material deposition.

3D Scanning Technology

3D scanning is the reverse process of 3D printing. Instead of creating a physical object from a digital model, it captures the geometry of a real object and converts it into a digital 3D model.
Devices such as the CR-Scan Raptor use advanced optical systems to accurately capture surface geometry and fine details.

G-CODE

                            N##: Line Number.
                            G##: Motion.
                            X##: Horizontal Position (X axis).
                            Y##: Vertical Position (Y axis).
                            Z##: Depth (Z axis).
                            F##: Feed Rate.
                            S##: Spindle Speed.
                            T##: Tool selection.
                            M##: Miscellaneous functions.
                       

ISO 7 Types of Additive Manufacturing

Type Main Technology Application
VAT Photopolymerization SLA / DLP / MSLA High precision parts
Material Jetting PolyJet Realistic models
Binder Jetting Powder + binder Fast production
Material Extrusion FDM Functional prototypes
Powder Bed Fusion SLS / SLM / DMLS Industrial metal/polymer parts
Sheet Lamination LOM / UAM Prototypes
Directed Energy Deposition DED Metal repair & aerospace

FDM vs Resin

Criteria FDM Resin
Detail Good Excellent
Strength High Medium
Size Large parts Limited by vat
Post-processing Minimal Wash + UV curing

Main FDM Materials

Material Main Advantage Main Limitation
PLA Easy & affordable Low heat resistance
ABS Impact resistant Warping & fumes
PETG Balanced strength Stringing
Nylon Very tough Moisture sensitive
TPU Flexible Slow printing

Design Rules for FDM

  • Overhang limit: 45° without supports
  • Minimum wall thickness: 1.2 mm recommended
  • Clearance for moving parts: 0.2 – 0.4 mm
  • Bridging: Works best under 20 mm spans
  • Layer height affects resolution and time

Key Factors for Quality

  • Layer height
  • Nozzle diameter
  • Temperature control
  • Print speed
  • Cooling
  • Material humidity

Projection of Light Pattern

The scanner projects:

  • Structured blue light
  • Or laser lines

onto the object’s surface.

Image Capture

High-resolution cameras detect how the projected light deforms over the object's surface.

Since the deformation depends on surface depth and shape, the system can calculate spatial geometry.

Triangulation Process

Using optical triangulation:

  • The projector emits light.
  • Cameras capture the reflection.
  • Software calculates depth using geometric relationships between projector and camera angles.

This produces a point cloud (millions of 3D points).

Mesh Reconstruction

The software then:

  • Aligns multiple scans (if needed).
  • Merges point clouds.
  • Generates a polygon mesh (usually STL or OBJ format).
  • Cleans noise and fills holes.

Export for Manufacturing

The final model can be:

  • Edited in CAD
  • Reverse engineered
  • Sent to a slicer
  • 3D printed
  • Used for inspection or quality control

Key Technical Concepts in 3D Scanning

Parameter Description
Accuracy How close the scan is to real dimensions (e.g., ±0.02 mm)
Resolution Level of detail captured
Scan Volume Maximum object size
Tracking Mode Marker-based or feature-based
Light Source Blue light (less ambient interference)
Output Format STL, OBJ, PLY

Resin 3D Printing

Anycubic Overview

Anycubic is a manufacturer of consumer and professional 3D printers, especially known for its resin (MSLA) printers such as the Photon series.
Along with the hardware, Anycubic provides slicing software (like Photon Workshop) that allows users to prepare 3D models for printing by configuring supports, hollowing models, setting exposure parameters, and generating the final print file.
Here you can download AnyCubic Photon Workshop .
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Import the STL File

1- The first step is importing the STL file into the workspace of the slicing software.
Once imported, the model appears in the 3D environment where it can be positioned, scaled, or modified before printing. And to modify the part, the tools located in the top toolbar and the right-side panel are used.
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Hollow the Model

2- The first step before printing is to hollow the model using the Hollow tool. Assign an appropriate thickness to its walls. In my case, I selected a thickness of 3 mm. The Hollos function is useful for saving resin and preventing it from detaching from the bed, which in this case is upside down.
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Punchw the Model

3- We will then add two holes in order to release the air inside the figure and the residual resin.
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Supports Setup

4- Next, we tilt the model approximately 15 degrees to minimize the surface area of each layer. This significantly reduces suction force during layer separation, improves print quality, allows better resin drainage, and decreases the risk of detachment from the build plate.
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5- After orienting the model, supports must be added to ensure structural stability during printing. The software provides three types of supports: Light, Medium, and Heavy. In this case, Heavy supports are selected because they provide stronger adhesion and better grip to the build plate.
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6- To see more settings, click on "more settings" and adjust the parameters.
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In the end it looks like this
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6- To slice we have to click the button in the bottom right. But before slicing we have to make sure of having the correct resin and the right machine. In my lab we have High Speed Resin, so that is the one I used.
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7- The final step would be to click on the slice and go to the printer.
       The printer used is the ANYCUBIC PHOTON M5s.
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The first step is to insert the USB drive containing the sliced file into the printer.
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After removing the printer cover, make sure the resin tank’s plastic film (FEP) is in good condition (it must not be punctured, scratched, or have cured resin stuck to it). Any damage can cause print failure or resin leakage.
Next:
  • Use the Move menu to raise the build plate to a comfortable working height.
  • Return to the main menu and select the file from the USB drive.
  • Start the printing process. The machine will begin lowering the build plate into the resin and curing layer by layer until the object is completed.
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Once the print is finished:
  • Carefully remove the build plate.
  • Detach the printed part using a scraper.
  • all supports carefully to avoid damaging the surface of the model.
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Finally, the post-processing stage:
  • Clean the piece using a paper towel and isopropyl alcohol (IPA) to remove uncured resin.
  • Then place the model into the Anycubic Wash & Cure 3 machine.
  • Use the curing function to fully harden the resin under controlled UV light exposure.
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Filament 3D Printing

3D scanning

For the 3D scanning process, the CR-Scan Raptor was used. This scanner belongs to the Creality ecosystem and operates with CrealityScan.
CrealityScan is the official 3D scanning software developed by Creality. It allows users to control compatible scanners, perform calibration, process scan data, align frames, generate meshes, optimize geometry, and export ready-to-use 3D models.
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After downloading and installing the software, the first step is to connect the scanner to the computer and synchronize it with the software.
  
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The CR-Scan Raptor kit includes:
  • The scanner unit
  • HDMI cable
  • USB cable
  • Power supply connector (female jack input)
  • Additional accessories included in the kit
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Calibration Process

  • The kit includes a calibration board with coded reference points.
  • This board is used to calibrate the scanner’s laser and optical system to ensure dimensional accuracy.
Calibration is performed by positioning the scanner at different angles and distances relative to the calibration board. The software guides the process to properly adjust the laser alignment and camera parameters.
  
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Creating a New Project

  • Once calibration is complete, a new project is created within the software.
  • The user selects the scanning mode depending on the object size and required precision.
  
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Scanning Process

The scanning workflow is intuitive:
  • The scanner includes built-in physical buttons that allow starting the scan directly from the device.
  • The process can also be initiated from the CrealityScan application.
  • The operator simply moves the scanner around the object while maintaining proper distance and steady motion.
  
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Exporting the Model

  • Once scanning is complete, click “One-click Process”
  • This automatically performs alignment, noise removal, mesh generation, and basic optimization.
  • After processing, select Export.
  • The file can be saved in formats such as STL or OBJ for further use in CAD software or 3D printing.
  
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My Piece

The figure designed is the Wither from Minecraft.
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Creating the Skeleton

The first step is to create a sketch on the lateral plane and extrude a segmented skeleton divided into four modules.
These four modules represent:
  • Modules 1–3 → Main body segments
  • Module 4 → Tail
This modular structure allows controlled articulation between sections.
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Creating the Ribs

The next step is to create the ribs for modules 1–3 (module 4 acts as the tail).
These ribs are simply square profiles extruded a few centimeters.
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Symmetry Setup

To facilitate the creation of moving parts and ensure perfect alignment, a construction plane must be created by Geometry → Plane
This plane should be positioned at the center of the skeleton.
It helps to:
  • Maintain symmetry
  • Mirror features accurately
  • Ensure proper alignment of rotational joints
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Moving Geometry

When designing articulated or moving parts for FDM (filament) printers, certain design rules must be followed to ensure functionality.
Important FDM Design Rules for Moving Parts:
  • Clearance Rule → A gap between moving parts is required.
  • Recommended tolerance for standard FDM printers: 0.5 mm – 0.8 mm
In this case, 0.7 mm
  
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Creating the Heads

To create the Wither’s heads:
  • Extrude a bar on the top of module 1.
  • Create three cubes.
  • Distribute them evenly along the bar.
This reproduces the characteristic triple-head structure.
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Extra: Hanging Ring

To allow the piece to be hung anywhere, a ring is added on top of the main head.
Design consideration:
  • The ring must have sufficient thickness (minimum 2–3 mm).
  • The internal hole must respect FDM clearance rules if integrated with moving parts.
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To finish, the model must be exported as an STL file in order to proceed to the next tab.

Meshmixer

Is a free software developed by Autodesk intended for easy creation of 3D mashups.
Lets you sculpt, repair, slice, hollow, and blend STL/OBJ files. And you can download here.
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1- Importing the STL File

An STL file can be imported either:
  • From the main screen
  • From the Files tab within the software.
Once selected, the model is loaded into the workspace as a mesh body.
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2- Converting the Mesh into a Solid

With the STL placed in the workspace, the next step is to convert the mesh into a solid body.
This is important because:
  • Mesh bodies are composed of triangular facets.
  • Solid bodies allow parametric editing and advanced modifications.
  • Many modeling tools require solid geometry to function properly.
After converting it to a solid, the Transform tool can be used to:
  • Move
  • Rotate
  • Reposition
The body within the 3D space.
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3- Scaling and Cleaning the Geometry

Once the model is properly positioned:
  • It can be scaled to the desired dimensions.
  • Using the Select tool, unwanted mesh areas or unnecessary geometry can be removed.
Cleaning the mesh improves:
  • Print reliability
  • Surface quality
  • Processing performance
This step ensures the model is optimized before final export.
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Finally, the edited model is exported again as an STL file, making it ready for slicing and printing.
With these basic tools and a series of precise adjustments, we transform a simple mesh into a fully refined 3D model.
And with that workflow… we arrive at this masterpiece.
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UltiMaker Cura Overview

UltiMaker Cura is a slicing software used to prepare 3D models for filament (FDM) printers.
In simple terms, Cura converts a 3D model (STL) into G-code, which is the language the 3D printer understands. It allows users to configure printing parameters such as layer height, speed, temperature, supports, and adhesion settings.
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1- Selecting the Printer

Once the application is open, the first step is to select or add a printer:
  • Click on the top tab and select Add Printer.
  • Choose whether your printer belongs to the Ultimaker group or is a non-Ultimaker machine.
  • Finish by adding your local printer from the list provided in the menu.
This ensures Cura generates compatible G-code for your specific machine.
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2- Importing the STL File

After setting up the printer:
  • Import the STL file from the Files tab
  • Click the folder icon located in the upper toolbar.
The model will appear on the virtual build plate.
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3- Workspace

The Cura workspace is divided into:
  • Left Sidebar
  • Contains transformation tools to manipulate the model in 3D space:
    • Move

    • Scale

    • Rotate

    • Mirror

  • Top Bar
  • At the top of the interface, you will find:
    • Project import icon

    • Selected printer

    • Selected filament material

    • Print settings profile
    Print settings profile:
      Quality:

      - Sets the overall print resolution and layer height of the model.

      Walls:

      - Controls the thickness and number of outer walls of the object.

      Top/Bottom:

      - Defines the number of solid layers on the top and bottom surfaces.

      Infill:

      - Determines the internal structure density and pattern of the model.

      Material:

      - Sets nozzle temperature, bed temperature, and flow rate according to the filament type.

      Speed:

      - Controls how fast the printer moves while extruding material.

      Travel:

      - Manages non-printing movements and retraction settings.

      Cooling:

      - Controls the cooling fan speed during printing.

      Support:

      - Generates temporary structures to hold overhangs and complex geometries.

      Build Plate Adhesion:

      - Adds structures like Skirt, Brim, or Raft to improve bed adhesion.

      Dual Extrusion:

      - Allows printing with two materials or colors using a dual-extruder printer.

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Parameters that I use:

Setting Group Parameter Value
Quality Layer Height 0.28 mm
Quality Initial Layer Height 0.2 mm
Walls (Shell) Wall Thickness 2 mm
Top/Bottom Top Layers 4
Infill Density & Pattern 10%
Speed Print Speed 100 mm/s
Material Bed Temperature 80 °C
Material Nozzle Temperature 210 °C
Adhesion & Support Build Plate Adhesion Brim / Skirt
Support Support Structure Tree
Cooling Fan Speed 100%

4- Slicing and Preview

Once the parameters are configured:
  • Click the Slice button located at the bottom of the settings panel.
  • Click Preview to visualize how the printer will build the object layer by layer.
Finally:
  • Click Save to Disk.
This generates a G-code file, which is transferred to the 3D printer via USB or SD card.
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In this case, the Creality Ender-3 S1 Pro 3D printer was used.
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We start by taking the SD card included with the printer.
To access it from the computer, we use an SD to USB-C adapter (in this case), allowing us to transfer files easily.
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Once the G-code file has been saved onto the SD card, we insert it back into the printer.
On the printer’s touchscreen interface, we navigate to the “Print” menu.
Inside this menu, we search for the file using the name previously assigned in the slicer software.
After selecting the file, we simply press Start
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Results

Resin 3D Printing

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Filament 3D Printing

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Files

Due to the nature of the files (which are mostly mesh-based), it was not possible to upload them on this occasion, as they are too large and difficult to transfer.
The Mr. Darcy statue is the intellectual property of arturosierraq, and it can be found on Cults3D.