5. 3D PRINTING AND SCANNING

Objectives

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)

Group Assignment

We downloaded an all-in-one test model and 3D printed it.A model was printed for clearance test. After printing, we analyzed the model and recorded the measured values for future reference. We learned about 3D printing, its process and types.We also discussed about printer and safety measures.

Bridge test - 20 mm

Diameter test -

• Actual value - 6mm
• measured value - 5.88mm

Overhang test - 45 deg

Clearance test - 0.3 mm

group assignment page

3D PRINTING

3D printing, also called additive manufacturing, is a technique for creating three-dimensional objects by layering materials based on a digital design. Unlike traditional manufacturing, which involves cutting or molding, 3D printing builds objects from the ground up, reducing waste and enabling intricate designs.

How it works ?

• Designing the Model
  • A 3D object is created using computer-aided design (CAD) software or scanned with a 3D scanner.
  • The design is then converted into a stereolithography (STL) file or another format suitable for 3D printing.
• Slicing the Model
• The 3D model is digitally divided into thin layers using slicing software.
• The sliced file is sent to the 3D printer for fabrication.
• Printing Process
• The printer builds the object layer by layer, following the sliced model’s instructions.
• Various materials can be used, including plastics, resins, metals, ceramics, and even biological substances.

Common printing techniques include:

• Fused Deposition Modeling (FDM) – Melts and extrudes plastic filament.
• Stereolithography (SLA) – Uses UV light to cure liquid resin.
• Selective Laser Sintering (SLS) – Fuses powdered material using lasers.

Post-Processing

• After printing, the object may require cleaning, curing, or additional finishing, such as sanding or painting, to enhance its appearance and functionality.

Additive manufacturing vs Substractive manufacturing

Subtractive manufacturing shapes an object by removing material, while additive manufacturing constructs it by gradually adding layers of material. Subtractive methods have been in use for a longer time and are typically faster, making them well-suited for high-volume production. In contrast, additive manufacturing allows for the creation of intricate designs, such as hollow or nested structures, which are challenging or even impossible to achieve with subtractive techniques.

Bambu Lab A1

The Bambu Lab A1 is a high-speed Core XY 3D printer , offering smart automation features like auto Z-offset, auto flow calibration, auto belt tensioning, and real-time flow rate compensation.

Design 1

The design can be made substractively. I made a 3D model to explore how 3D printing works. To design the cube frame, I drew a 40mm square frame and extruded it. A 34mm square is cut out from all sides to make it a frame. The next part was to add a sphere. a sphere of diameter 45 mm is drawn and placed inside the cube frame using move tool as shown below.

The initial sketch for designing was done in fusion 360

The image is then exported as a step file. For the slicer, I downloaded Bambu A1 software

Bambu A1

I opened the file in the software

For support I selected tree type. Infill was 15. To select infill, strength → infill. I selected 0.24 mm as layer height. Select slice plate. After making necessary changes select print plate. Select the 3d printer and connect. Once the calibration is complete, printing process will start.

Instructor told me that the design can be made substractively using CNC milling. So another design was sketched in fusion. I added a torous to make it a keychain.

Design 2

The design was inspired from harry potter logo. To create the 3D model, first i drew a 40 mm triangle. I extruded the triangle into 3d and cutout a 30mm triangle from it. A 15 mm diameter sphere and a 32 mm long rod is created. A hole is created in the sphere to allow the free motion of sphere through the rod. The same feature makes it hard to mill using a CNC machine and through substractive manufacturing. The components are then arranged accordingly and the edges of triangle is chamfered to get a good finish.

Initial sketch was made in fusion 360.

The sketch is then exported as a step file and opened in Bambu Lab A1 slicer

The support was selected as tree type and infill as 30. Random seam was selected.Layer height was selected as 0.24mm

After making necessary changes, select print plate and select the printer in it.

Now we need to remove the support

3D Scanning

3D scanning is a technology that captures the shape, size, and details of a physical object or environment to create a digital 3D model. It uses specialized scanners to collect data from multiple angles, which is then processed into an accurate virtual representation.

How it works?

• Data Capture – The scanner projects light (lasers, structured light, or infrared) onto the object while sensors record how the light interacts with the surface.
• Depth Calculation – The scanner measures distortions in the projected light and calculates 3D coordinates for each point on the object.
• Point Cloud Generation – The collected points form a "point cloud," a raw representation of the object's shape.
• Model processing – Software converts the point cloud into a 3D mesh, which can be refined and exported for applications like 3D printing, virtual reality, or engineering.

Artec 3D scanner

The Artec Leo is a professional handheld 3D color scanner with automatic onboard processing and a touchscreen display for real-time model visualization.With an upgraded NVIDIA Jetson TX2 processor, it delivers faster processing speeds, enabling high-quality, real-time 3D data capture.

Scanning the object

I scanned a drill machine .

• Press and hold the power button to turn on the Artec Leo. Ensure the battery is charged or the scanner is connected to a power source.
• Adjust scan settings such as resolution, texture capture, and sensitivity based on the object. Maintain a working distance for optimal results.
• Point the scanner at the object and press the start scan button. Move smoothly around the object to capture all angles. Monitor the real-time 3D model on the touchscreen to ensure full coverage.
• Rotate and zoom in on the scanned model to identify any gaps. Rescan areas as needed for a complete and accurate capture.
• Transfer the scan to Artec Studio software on a PC for further processing, cleaning, and exporting in different formats.

Postprocessing

The scan is transferred to Artec Studio 15 software.

select the scan from file -> import

I selected autopilot. Option was shown to edit the scan. Unecessary parts in the background were erased.

Click next

After the process, we get the 3d model of drill machine. The processed scan is then saved in OBJ format.

3dscan by ancyraju77 on Sketchfab