5. 3D Scanning and printing

For this week, as an individual assignement, an Object should be designed and 3D-Printed, which could not be substractively made.

Research

There are many objects that can be made using additive 3D printing that would be difficult or impossible to create using subtractive methods like CNC machining or carving. Here is an example of an object that would be challenging to create subtractively, but could be easily designed and 3D printed.

Design: A small, intricate lattice structure

One advantage of 3D printing is the ability to create complex geometries that would be challenging to create using traditional subtractive methods. One such geometry is a lattice structure, which consists of a network of interconnected struts and voids. A lattice structure can be used for a variety of applications, including lightweight structural components, filters, and heat exchangers.

To design a lattice structure, a 3D modeling software like Autodesk Fusion 360 or SolidWorks could be used. At the begining a cube or sphere with the desired dimensions should be created, then could the lattice feature be used to create the structure. It's possible to experiment with different lattice patterns and densities to achieve the desired mechanical properties.

Printing: Using an FDM 3D printer

Fused Deposition Modeling (FDM) 3D printers are a popular and affordable option for creating small objects. To print the lattice structure, a material that can create thin, strong struts and handle the small details of the design should be choosen. PLA (polylactic acid) or PETG (polyethylene terephthalate glycol) are good options for this.

Once the lattice structure is designed, it is now possible to export it as an STL file and import it into the slicing software. In the slicing software, the settings for layer height, infill density, and support structures could be adjusted. For a lattice structure, it's better to use a low infill density to maximize the open space in the design.

After slicing, the file is now ready to be sent to the 3D printer and start the print job. Depending on the size and complexity of the lattice structure, the print time may range from a few minutes to several hours. Once the print is complete, the support structures could be removed and the object cleaned to reveal the intricate lattice structure.

Lattice structure in 3D-Design

Lattice structure in 3D-Design

1. I begin by creating a sketch that shapes the form of my 3D object. This initial design serves as the foundation for the entire project.



2. Next, I extrude the outer part of the object. My intention is to use these pieces as LED covers, so this step ensures they have the necessary depth and structure.



3. Expanding on that, I also extrude both the outer and inner parts. This additional layering ensures that the top of the object is fully covered, providing a seamless surface.



4. With the basic form in place, I turn to the Volumetric Lattice tool. Using this feature, I create an intricate pattern that adds visual interest and complexity to the design. The lattice not only enhances aesthetics but also contributes to the overall strength of the object.



5. Once satisfied with the 3D model, I export it as a .3mf file. This format allows me to transfer the design seamlessly to the Prusa Slicer software for further processing.



6. Now, let’s dive into the specifics of the 3D printing process:

   • Material: I choose PLA (Polylactic Acid) for its ease of use and environmental friendliness.

   • Nozzle size: I opt for a 0.4 mm nozzle, which strikes a balance between fine details and efficient printing.

   • Supports: I configure supports to generate only on the build plate. This ensures stability during printing without unnecessary overhangs.

   • Infill: I set the infill percentage to 15%. This determines the internal structure of the object, balancing strength and material usage.



7. Finally, I slice the model using the Prusa Slicer, generating the G-code necessary for my Prusa 3D printer to bring the object to life layer by layer.

3D Scanning Process

1. Setup

   I positioned the target object on a rolling chair, ensuring it was well-lit and visible from various angles. Next, I prepared my camera or smartphone to capture photos of the object.

2. Rotation Scanning

   I meticulously rotated around the object, capturing photos at each position. By circling the object, I obtained different viewpoints, allowing me to capture its shape comprehensively.

3. Multiple Angles

   I took photographs from various perspectives—top, bottom, sides, and diagonals. The more angles I covered, the greater the number of data points collected for accurate reconstruction.

Results:

• X-Ray Image:

  This image likely reveals the internal structure of the object, highlighting any hidden features or defects.

• Shaded Image:

  Shaded images provide a visual representation of the object’s surface, emphasizing its contours and texture.

• X-Ray Image (Again):

  The second X-ray image might capture different details or perspectives, complementing the first one.

Group Assignment: First Layer Test

For this critical assessment, I printed a small 20mm x 20mm square with a generously thick initial layer. By meticulously adjusting the Live-Z setting in PrusaSlicer, I fine-tuned the bed level. The outcome consistently met expectations across five distinct points on the bed.

Group Assignment: XYZ Calibration Cube Test

To verify the printer’s calibration, I meticulously printed a 20mm x 20mm x 20mm cube. Impressively, the dimensions were remarkably accurate, with only a minor deviation of +/-0.04 mm.

Group Assignment: Speed Tower Test

In this test, I meticulously programmed the slicer to employ varying speeds on each layer, ranging from 120 to 160 mm/s. Notably, we observed that increasing the speed led to a perceptibly rougher surface finish.

Group Assignment: Temperature Tower Test

To thoroughly evaluate temperature settings, I embarked on printing a temperature tower. PrusaSlicer allowed me to meticulously set different temperatures for each layer, spanning a range from 195°C to 235°C. Surprisingly, there was no discernible effect on the 3D print part due to temperature variations.

Group Assignment: Support Test

To rigorously assess support settings, I printed a model featuring varying overhang angles, holes, gaps and briging. Encouragingly, all the tests yielded successful results in this regard

Download Files

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What I've Learned from 3D Printing

3D printing, also known as additive manufacturing, has revolutionized how we create objects. Key takeaways include:

• Layer-by-Layer Fabrication: 3D printing builds objects layer by layer, allowing intricate designs and customization.
• Material Variety: 3D printers work with diverse materials, impacting the final object's performance.
• Design Freedom and Complexity: 3D printing enables complex geometries and lightweight structures.

Challenges of Subtractive Methods for Lattice Structures

Creating volumetric lattice structures using subtractive methods faces hurdles:

• Material Removal Limitations: Achieving intricate internal voids is challenging.
• Internal Complexity: Subtractive methods struggle to access hidden areas within lattices.
• Wasted Material and Time: Subtractive processes generate waste during removal.
• Structural Integrity: Removing material weakens lattice connections.