Week 5

5. 3D Scanning and Printing

Background

Introduction to 3D Scanning

Imagine being able to capture the world around you in stunning detail, creating digital replicas of real objects with just a click. That's the power of 3D scanning. This technology allows us to transform physical objects into digital models, opening up a world of possibilities for design, analysis, and preservation. Using techniques like laser scanning and photogrammetry, 3D scanners capture the shape and texture of objects, from small artifacts to entire buildings, with incredible accuracy. These digital models can then be used for a variety of purposes, from creating custom products to preserving cultural heritage.

Introduction to 3D printing

Now, picture being able to take those digital models and turn them into physical objects, layer by layer, right before your eyes. That's the magic of 3D printing. Also known as additive manufacturing, 3D printing allows us to create complex geometries and intricate designs that would be impossible with traditional manufacturing methods. From prototypes and tools to prosthetics and even food, the possibilities of 3D printing are endless. By building up materials like plastics, metals, and even living cells, layer by layer, 3D printers can create objects that are limited only by your imagination.

Significance of 3D Scanning and Printing

Together, 3D scanning and 3D printing are revolutionizing industries like manufacturing, healthcare, and art, making it faster, cheaper, and easier to create and innovate. Whether it's customizing products, replicating rare artifacts, or advancing medical treatments, these technologies are reshaping the way we think about design and production.

Tasks

This week has following tasks:

Group assignment: Test the design rules for your 3D printer(s) Here is our work of group assignments.

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)

Difference between substractive manufactring and additive manufacturing

Manufacturing Comparison

Aspect	Subtractive Manufacturing	Additive Manufacturing
Definition	Removes material from a solid block or workpiece to create a shape.	Builds up layers of material to create a three-dimensional object.
Process	Material is cut away using tools like drills, lathes, or milling machines.	Material is added layer by layer using 3D printers.
Material Efficiency	Generates waste as excess material is removed.	Highly efficient as material is added only where needed.
Design Flexibility	Limited by the cutting tools and machine capabilities.	Highly flexible, allowing for complex geometries and designs.
Time and Cost	Can be time-consuming and costly, especially for complex shapes.	Can be faster and more cost-effective for certain designs and volumes.
Post-Processing	Often requires additional finishing processes like polishing or painting.	Requires minimal post-processing, depending on the material and finish.
Examples	CNC machining, drilling, milling.	3D printing, stereolithography, selective laser sintering.

Modelling sphere gear

In this week I selected sphere gear part to print.Sphere gear is an element of gear pair which has teeth on its surface and mating gear can transmit part in any direction while revolving in 360 degree. This part is very difficult to manufacture using substractive manufacturing.Its geometry is also paramteric and depends on the module.I selected module 2 and number of teeth on formative spur gear as 30 as base geometry in solid works.

Selection of formative gear

Creating gear

Sketching the gear and selecting convert entities

Copied required entity of gears includes all arcs and centres

Trimming half gear

Converted to 3d plane and revolved about an axis

Base sphere gear is obtained

Now selected perpendicular plane and half is revolved cut

Final sphere gear

3D PRINTING OF SPHECRICAL GEAR

Need of slicer software

1.Generating Printing Instructions: Slicer software takes a 3D model in STL or OBJ format and slices it into thin layers, generating the toolpath and instructions (G-code) needed for the 3D printer to create each layer.

2.Customization and Optimization: Slicer software allows users to customize various printing parameters such as layer height, infill density, print speed, and support structures. This customization helps optimize the printing process for quality, speed, and material efficiency.

3.Support Generation: Slicer software can automatically generate support structures for overhanging parts of a model. These supports provide stability during printing and are later removed, ensuring that complex geometries can be printed successfully.

4.Bed Adhesion and Rafting: Slicers can generate rafts or brims to improve bed adhesion, especially for prints with a small base area. These features help prevent warping and ensure that the print adheres well to the build plate.

5.Toolpath Optimization: Slicers can optimize the toolpath to minimize travel time and reduce the risk of collisions between the print head and the printed object, improving print efficiency and quality.

Imported gear to slicer

Parameters while Printing

3D printed Gear model

From above process I understood the process of 3D printing.More focus should be kept on the accuracy of print ,resize and material selection for print.

3D Scanning

I used a 3D Scanner app to scan my face and created a 3D model of it using an iPad. For that I followed following procedure. 3D Scanning Process on iPad

Select a 3D Scanning App: Download and install a polycam 3D scanning app from the App Store that is compatible with iPad model.
Calibrate the App: Follow the app's instructions to calibrate the scanning process. This usually involves capturing a reference object or setting specific parameters.
Capture the Object: Place the object you want to scan on a stable surface in a well-lit environment. Use the app to start the scanning process.
Scan the Object: Move the iPad around the object, ensuring that you capture it from different angles. The app will guide you on how to move and position the device for optimal scanning.
Merge Scans (if needed): For larger objects or complex shapes, you may need to capture multiple scans and then use the app to merge them into a single 3D model.
Refine the Model: Some apps offer tools to refine the 3D model, such as smoothing rough areas or filling in gaps in the scan.
Export or Share the Model: Once you are satisfied with the 3D model, you can export it in a compatible format (e.g., STL, OBJ) for further editing or 3D printing, or share it with others.

After following above steps I got my face 3D scanned as below: raster