Assignment: 3D Scanning and Printing

Group assignment

test the design rules for your 3D printer(s).

Individual assignment

• design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively
• 3D scan an object (and optionally print it)

Introduction

Individual assignment

For this assignment, I designed and 3D printed a gear that could not be manufactured through subtractive methods due to its intricate geometry and parameter-driven adaptability. The object was designed using SolidWorks and fabricated using a Anycubic Kobra 2 neo 3D printer.

Various Manufacturing Processes Explored

In this assignment, I explored both additive and subtractive manufacturing processes:

Additive Manufacturing (3D Printing): Utilized the Anycubic Kobra 2 Neo FDM printer to fabricate a complex gear design. This process builds objects layer by layer, allowing for intricate geometries that are challenging to achieve with traditional methods.

Subtractive Manufacturing (3D Scanning): Employed the Kiri Engine app to scan a physical toy, capturing its geometry by removing material from a digital model to create a 3D representation. This method is beneficial for reverse engineering and replicating existing objects.

Advantages and Limitations of 3D Printing

Advantages:

Design Flexibility: Enables the creation of complex and customized designs without the constraints of traditional manufacturing.

Rapid Prototyping: Accelerates the development process by allowing quick iterations and testing of designs.

Cost-Effective for Small Batches: Reduces costs for low-volume production runs, eliminating the need for expensive molds or tooling.

Material Efficiency: Minimizes waste by using only the necessary material for each build.

Limitations:

Material Constraints: Limited to specific materials, primarily certain plastics and metals, which may not be suitable for all applications.

Surface Finish and Strength: Printed parts may require post-processing to achieve desired surface quality and may not match the strength of traditionally manufactured parts.

Size Restrictions: The build volume of printers limits the size of parts that can be produced in a single print.

Production Speed: While suitable for prototyping, 3D printing can be slower than traditional methods for mass production.

3D Printer Used in the Lab

The Anycubic Kobra 2 Neo FDM 3D printer was utilized for this assignment. Key features include:

Printing Technology: Fused Deposition Modeling (FDM)

Build Volume: 220 x 220 x 250 mm

Layer Resolution: 0.1 – 0.4 mm

Nozzle Diameter: 0.4 mm

Filament Compatibility: PLA, ABS, PETG, and TPU

This printer offers user-friendly features such as automatic bed leveling and a touchscreen interface, making it suitable for both beginners and experienced users.

Software Used:

The 3D model was created using SOLIDWORKS 2023, a professional-grade CAD software. The design was exported for slicing using a compatible slicer software like Cura or Anycubic Slicer to prepare it for 3D printing.

Visit SolidWorks Official Website

Step 1 – Part Creation:

The process began by opening SOLIDWORKS and creating a new Part document. A sketch was initiated on the Front Plane to begin shaping the base profile of the object.

Step 2 – Sketching the Profile:

A semicircular arc was drawn along with a vertical line to form the profile of a sphere. This sketch defined the basic shape that would later be revolved into a 3D body.

Step 3 – Revolve Feature:

Using the Revolved Boss/Base feature, the semicircle was rotated 360° around the central axis to form a complete sphere. This became the base body for all subsequent operations.

Step 4 – Top Cut Creation:

A circular cut was made from the Top Plane using the Cut-Extrude tool. This created an open top on the sphere, introducing a hollow passage and internal visibility.

Step 5 – Triangular Cutout:

An angled reference plane was created and used to sketch a triangle. This triangular profile was then extruded through the sphere in both directions, forming a sharp, internal cutout that passes through the body.

Step 6 – Intersecting Cut:

A second cross-cut was created from a different angle with a circular or hexagonal shape. This cut intersected with the previously formed internal geometry, creating a complex network of openings.

Step 7 - Exporting the 3D Model as STL:

Once the 3D design was finalized in SOLIDWORKS, it was exported in the STL format, suitable for 3D printing. The mesh had 8,116 triangles and a size of 405 KB, ensuring a well-optimized model for slicing.

Step 8 - Opening the STL in Anycubic Slicer:

The STL was imported into Anycubic Slicer v1.4.4 for use with the Anycubic Kobra 2 Neo printer. The model was placed on the virtual build plate, and slicing settings such as PLA filament and 0.20 mm layer height were selected.

Visit Anycubic Official Website

Step 9 - Slicing Settings Configuration in Anycubic Slicer

To prepare my 3D model for printing, I used Anycubic Slicer version 1.4.4 with the printer profile set to KOBRA2 NEO and layer height profile of 0.20mm NORMAL. Below are the customized slicing parameters I used:

1. Layers and Perimeters

• Layer height: 0.2 mm
• First layer height: 0.28 mm (to improve bed adhesion)
• Perimeters: 3 vertical shells for structural strength
• Spiral vase: Disabled

2. Infill Settings

• Fill density: 10% (for faster print and material saving)
• Fill pattern: Grid
• Top/Bottom fill pattern: Monotonic
• Infill anchor length: 10 mm (for consistent anchoring)

3. Support Material

• Generate support material: Enabled
• Overhang threshold: 10° (for better overhang control)
• First layer density: 90%
• First layer expansion: 4 mm (to enhance support contact)

4. Speed Settings

• Perimeters & infill: 150 mm/s
• Top solid infill: 120 mm/s
• Support material: 50 mm/s
• Bridges: 40 mm/s
• Ironing: 15 mm/s (for surface finishing)

Step 9 - Slicing the Model:

Settings such as infill density, brim support, and build plate adhesion were applied. The slicing process estimated a print time of 1 hour 43 minutes and required approximately 13.09 meters (39.03 grams) of filament.

Step 10 - G-code Generation:

The sliced file was exported as ball.gcode and saved to a USB drive. This G-code file contains all the instructions needed by the printer to produce the model.

3. 3D Printing Process

Loading the Filament

I used a 1.75 mm PLA filament of purple color. The filament was loaded into the extruder by manually guiding it through the Bowden tube.

Heating the Nozzle

Before printing, I set the nozzle to heat up to 215°C, which is suitable for PLA material.

Selecting the Print File

Using the 3D printer interface, I selected the sliced G-code file named ball-0.2-31m-ac-pla-5-31.g for printing.

Starting the Print

The sliced file was inserted through a USB stick, and the print was initiated.

Final Printed Output

The final printed object is a geometrically complex hollow sphere with angled internal cutouts. The print quality was clean, and the overhangs were handled well with the support structures.

Machine & Settings Used

• Printer: Anycubic Kobra Go
• Filament: PLA (1.75 mm, Purple)
• Nozzle Temperature: 215°C
• Bed Temperature: 60°C
• Layer Height: 0.2 mm
• Infill Density: 20%
• Support: Enabled
• Print Time: Approx. 1 hour 30 minutes

Hero shot

1. Selecting the Object

The object chosen for scanning was a small toy. This was selected due to its distinct shape and well-defined features, making it suitable for 3D reconstruction.

Visit Kiri Engine Official Website

The first image shows the real toy used for scanning.

2. Capturing Multiple Angles

To ensure an accurate 3D scan, multiple images of the toy were taken from different angles using the Kiri Engine.

The next image displays the collected photos, covering all perspectives required for proper model generation.

The settings were adjusted to export the model in OBJ format, which is compatible with 3D printing and further modifications.

3. Rendering and Viewing the 3D Model

The app processed the images and generated a 3D model, converting it into a mesh representation.

Once the rendering was complete, the OBJ file was displayed within the Kiri Engine.

The generated model was inspected for accuracy, ensuring that the shape and details were preserved from the original object.

4. Final Out

The next image presents the final 3D file of the scanned object.

Once the rendering was complete, the OBJ file was displayed within the Kiri Engine.

The generated model was inspected for accuracy, ensuring that the shape and details were preserved from the original object.