5. 3D Scanning and Printing¶

Assignment for Week 5¶

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)

Here is the Link for the group assignment.

Group Assignment Highlights¶

3D printers and Design Rule Test¶

a. Prusa i3 MK3¶

Design Rule Test for Prusa¶

Nozzle Size Impact on Text Quality:
0.4 mm nozzle resulted in unclear small text.
Smaller nozzles (0.2 mm or 0.25 mm) recommended for finer details.
Bridging Test:
Clean bridging up to 5 mm; longer spans may need tuning or supports.
Hole and Diameter Test:
Accurate hole depth printing; smaller diameters less precise.
Adjustments (flow rate, speed, cooling) or smaller nozzle needed for better accuracy.
Overhang Performance:
Successful prints up to 60 degrees without supports.
Supports required from about 60 degrees.

b. Bambu X1 Carbon¶

Design Rule Test for Bambu X1 Carbon¶

Nozzle Size Impact on Text Quality: - A 0.4 mm nozzle resulted in suboptimal text clarity. - Smaller nozzles (e.g., 0.2 mm or 0.25 mm) are recommended for finer details like small text.

Overhang Performance:
The printer handled overhangs well, achieving clean prints up to 60 degrees without supports.
Indicates strong cooling and extrusion control.
Bridging Capability:
Bridging was clean and effective up to 5 mm.
Longer spans may require tuning or supports.
Hole Depth and Diameter:
Accurate hole depth printing demonstrated consistency in vertical dimensions.
Smaller hole diameters were less precise; larger diameters printed well.
Adjustments (e.g., flow rate, speed, cooling) or a smaller nozzle may improve small hole accuracy.

Individual Assignments¶

3D Printing and Additive Manufacturing¶

3D printing, also known as additive manufacturing, is a transformative technology that builds three-dimensional objects layer by layer from a digital model. Unlike traditional manufacturing methods, which often involve cutting or drilling material away from a solid block (subtractive manufacturing), 3D printing adds material only where needed, reducing waste and enabling complex geometries that would be difficult or impossible to achieve otherwise. This technology has revolutionized industries ranging from healthcare and aerospace to automotive and consumer goods.

Types of 3D Printing Techniques¶

I went through this website to understand types of 3D printing techniques.

There are several types of 3D printing techniques, each with its own strengths and limitations. The most common methods include:

Fused Deposition Modeling (FDM)
- How it works: FDM uses a thermoplastic filament, which is heated and extruded through a nozzle to create layers.
- Pros: Low cost, widely available, and easy to use.
- Cons: Lower resolution and strength compared to other methods.
- Applications: Prototyping, hobbyist projects, and functional parts.

Stereolithography (SLA)
- How it works: SLA uses a laser to cure liquid resin into solid layers.
- Pros: High resolution and smooth surface finish.
- Cons: Limited material options and post-processing required.
- Applications: Dental models, jewelry, and detailed prototypes.

Selective Laser Sintering (SLS)
- How it works: SLS uses a laser to sinter powdered material (e.g., nylon) into solid layers.
- Pros: No need for support structures, strong and durable parts.
- Cons: Expensive equipment and materials.
- Applications: Functional prototypes, end-use parts, and aerospace components.

Digital Light Processing (DLP)
- How it works: Similar to SLA, but uses a digital light projector to cure resin.
- Pros: Faster than SLA and high resolution.
- Cons: Limited material options and post-processing required.
- Applications: Dental models, jewelry, and small detailed parts.

Multi Jet Fusion (MJF)
- How it works: MJF uses inkjet arrays to deposit fusing and detailing agents onto a powder bed, which is then fused by heating.
- Pros: High speed, excellent surface finish, and strong parts.
- Cons: Limited material options and higher cost.
- Applications: Functional prototypes, end-use parts, and industrial components.

Direct Metal Laser Sintering (DMLS) / Selective Laser Melting (SLM)
- How it works: These methods use a laser to sinter or melt metal powder into solid layers.
- Pros: High strength and precision, suitable for complex metal parts.
- Cons: Expensive and requires specialized equipment.
- Applications: Aerospace, medical implants, and automotive parts.

Pros and Cons of Additive Manufacturing¶

Pros:
- Design Freedom: Enables the creation of complex geometries and internal structures.
- Customization: Ideal for producing customized or one-off parts.
- Reduced Waste: Uses only the material needed, minimizing waste.
- Rapid Prototyping: Accelerates the design and testing process.
- Cost-Effective for Low Volumes: Eliminates the need for expensive molds or tooling.

Cons:
- Material Limitations: Not all materials are suitable for 3D printing.
- Surface Finish: Often requires post-processing to achieve a smooth finish.
- Speed: Can be slower than traditional manufacturing for large-scale production.
- Cost: High initial investment for industrial-grade printers.
- Strength and Durability: Some 3D-printed parts may not match the strength of traditionally manufactured parts.

Applications of Additive Manufacturing¶

Prototyping: Rapidly create and test designs.
Healthcare: Produce custom prosthetics, implants, and surgical guides.
Aerospace: Manufacture lightweight, complex components.
Automotive: Create custom parts and tools.
Consumer Goods: Design personalized products and accessories.
Construction: Print building components or even entire structures.
Education: Teach design and engineering concepts through hands-on projects.

By leveraging the unique capabilities of 3D printing, industries can innovate faster, reduce costs, and create products that were previously unimaginable. As the technology continues to evolve, its potential applications will only expand, making it a cornerstone of modern manufacturing.

3D Printing¶

For 3D printing which can not done subtrictively. I decided to design a simple bearing. I learned how to design this from my local instructor Yeshi.
Open Fusion360
Sketch some circles to model the bearing
Select the parts to extrude
Extrude it
Now use pipe to form a curve inside the bearing ring so it can hold the bearing balls
Add fillet to the all the edges of the bearing so that it can have a smooth edges
Add one sphere.
Position the bearing ball between the bearing rings
Mirror the bearing ball and create more bearing balls
More bearing balls
Final Result
Export the bearing model as .stl file
Open Prusa Slicer so that you can slice and get the G-code for 3D printing. Specify all the setting like Print setting, Filament, Printer, Support and Infill density. Then click on “Slice now” to slice.
Once sliced, check whether the support type fits your requirement and also the estimated filament use , and estimated printing time. After checking all the information of sliced model, export the G-code for printing.
Take the generated G-code in SD card and 3D printed it using Prusa i3 MK3
3D printed bearing.

3. 3D scanning¶

For 3D scanning, I ended up using Kiri Engine after exploring a few scanning app like Scaniverse and Polycam.

Downlaod the Kiri app from here. And installed on my mobile phone.
I want to scan something very simple without complex design. I decided to try using a vase. I place it on a table.
I created an account to use the Kiri Engine.
Go to Scans option and click on + menu.
Click on Photo Scan.
Click on Take Photoes/Videos.
I took 100 photo in auto mode so that it can be easier for me to take 100 of them.
Once finished taking the pictures give the polygon counts, Texture Resolution and Texture Smoothing.
Also select the file type for download. I choose .stl as my result file so that I can import it on other CAD software and edit it.
I uploaded the images to Kiri server for processing.
Processing the model will take sometime but the result came out quite nice.
You can now export this model to edit in CAD software like Fusion360 and Blender.

4. More 3D Printing¶

i. Reject 3D printing as it is not my own design but edited version of open source design. Also, Rico and Miriam pointed out in Asian Review that this can be done subtractively. - I edited the existing Rabbit model which is open source and edit it in Blender. - I downloaded the Rabbit model’s .STL from here - Import the model in Blender

This is the imported Rabbit model
Using the following list of Modifiers, I edited the model which looks something like this. i. Decimate Modifier ii. Wireframe Modifier iii. Subdivision Surface Modifier iv. Solidify Modifier

Then I downloaded the Bambu Stdio from here so that I can use it to slice and 3D print.
Import the your .stl model exported from Blender into Bambu Stdio for slicing. Also choose the printer (I used Bambu X1-Carbon) and select the build plate(I used Textured PEI Plate).
Then I changed the default Sparse infill density to 35% and also change the Sparse infill pattern to Archimedean Chords.
I printed it with noraml(auto) support.
but I realized that it is very hard to remove the normal auto generated support from my model
Hard time removing support.
So I printed it again but this time using Tree(auto) support.
Preparing to Print
Print successful
Removing the support( much easier this time)
Final Result