Week 05. 3D Scanning and Printing¶
Group Assignment:¶
- Test the design rules for your 3D printer(s)
- Document your work on the group work page and reflect on your individual page what you learned about characteristics of your printer(s)
Points to be Remembered¶
- From the design rule test of Prusa i3 MK3S, support is required after an angle 60 degree.
- Upto 2cm it can print over without supports, eliminating the need for filament underneath the bridge.
- Stringing or oozing also known as “hairy prints issue is caused by very high printing temperatures and/or using incorrect retraction settings.
Additive vs. Subtractive Manufacturing¶
This definination (for my own understanding) is genertaed from chatGPT: Additive manufacturing is a process that adds successive layers of material to create an object, often referred to as 3D printing. Subtractive manufacturing, as the name suggests, is the opposite. Rather than adding layers, subtractive manufacturing involves removing sections of a material by machining or cutting it away. It can be carried out manually or, more commonly, by a process known as Computer Numerical Control (CNC) machining.
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image from this source
Key Differences:
| Additive Manufacturing | Subtractive Manufacturing |
|---|---|
| Makes an object by adding materials layer by layer | Removes material from the workpiece to make product |
| Can create intricate and complex product | better for simple shapes |
| It used only ther required amount of material thus minimizing wastage of material | It generate more amount of waste during machining process |
Advantages of Additive Manufacturing:
- Best for creation of intricate geometries and designs.
- Facilitates mass customization for personalized products.
- Minimizes waste material by using only what’s necessary.
- Complex assemblies can be consolidated into single parts.
- Recommended to small businesses and hobbyists.
Disadvantages of Additive Manufacturing:
- Limited Material Selection
- May result in rougher surfaces requiring post-processing.
- Limited by the size of the printer’s build volume.
- Parts may exhibit inferior mechanical properties compared to traditional methods.
- Additional steps like support removal and surface treatment may be necessary.
Types of 3D Printers¶
image from google source
The following definitions(for my own understanding) are generated using chatGPT:
- Fused Deposition Modeling (FDM): FDM printers work by heating and extruding thermoplastic filament layer by layer to build the object. Example: Creality Ender 3, Prusa i3 MK3S.
- Stereolithography (SLA): SLA printers use a liquid resin that is cured layer by layer using a UV laser or light projector.Example: Formlabs Form 3, Anycubic Photon Mono.
- PolyJet 3D printers: PolyJet 3D printers utilizes photopolymer materials cured by UV light to build objects layer by layer. Example: Stratasys J55, Stratasys J5 DentaJet, Stratasys J8 Series
- Selective Laser Sintering (SLS): SLS printers fuse powdered material together using a high-powered laser to create the object layer by layer.Example: Sinterit Lisa, EOS P 396.
- Digital Light Processing (DLP): DLP printers use a digital light projector to cure liquid resin layer by layer.Example: Wanhao Duplicator 7, Phrozen Sonic Mini.
- Binder Jetting: Binder jetting printers selectively deposit a binding agent onto a powder bed, solidifying the material layer by layer.Example: ExOne M-Flex, Desktop Metal Studio System.
- Material Jetting: Material jetting printers spray liquid photopolymer onto a build platform, which is then cured layer by layer. Example: Stratasys J750, 3D Systems ProJet 660.
Individual Assignment:¶
- Design and 3D print an object (small, limited by printer time) that could not be easily made subtractively
- 3D scan an object (and optionally print it)
Designing 3D Object¶
- Utilizing SolidWorks, I designed a geodesic structure to fit inside a cube. The design primarily relied on SolidWorks’ surface feature for construction.
- I start by sketching the initial design on the top plane in SolidWorks, ensuring to input the required dimensions accurately with fully defined sketch denoted by black sketch. This stage lays the foundation for the entire structure.
- After getting fully defined 2D design, I then used surface revolve and surface cut feature.
- I create additional planes and axis lines as needed to support the complexity of the design. These elements serve as reference points for further construction and alignment.
- Employing SolidWorks pattern features, I efficiently replicate key components or features across the design, saving time and effort while maintaining consistency throughout the structure.
- Leveraging the Move/Copy Body command within SolidWorks, I precisely position and manipulate components to achieve the desired arrangement and alignment.
- Using Combine feature. This step unifies the separate bodies, creating a single, integrated structure ready for further refinement or export.
Printing 3D Object¶
- Import .stl file into Prusa slicer to generate G-code for 3D printing. Within PrusaSlicer, I took advantage of the Expert Mode functionality, which enables precise placement of supports only where necessary. This feature significantly reduces the need for post-processing support removal.
- Once satisfied with the slicing settings, I proceed by selecting “Export G-code” located at the bottom right corner of the PrusaSlicer interface. Afterward, I save the generated G-code file onto an SD card. Subsequently, I insert the SD card into the 3D printer. Upon insertion, the printer’s interface displays the contents of the SD card. To initiate the printing process, I navigate to the G-code file, typically listed in chronological order with the most recent file appearing first, and select it using the printer’s control knob. This action prompts the printer to commence the print job based on the instructions provided within the G-code file.
image from internet - After print this is how it looks:
- Supports were removed and this is final look:
- In the second print, I decreased the size of the cube to 3cm to eliminate the need for support structures.
When attempting to print a Möbius Bracelet designed in SolidWorks using both Prusa and Form printers, I encountered an issue due to the bracelet’s intricate design. Specifically, the diameter of the bracelet’s three joints or threads was exceptionally small, leading to difficulties in removing support materials on both printers.
The challenge persisted during the post-processing stage, particularly when removing the support materials. Unfortunately, this process resulted in the breaking of the models, leading to the failure of the printing attempts.
Using SolidWorks, I designed bouncy balls and 3D printed with PLA material on a Prusa 3D printer. I printed them out with the Prusa, and it looks great. Now, it is ready to bring lots of fun to anyone who wants to play with it😂
3D Scanning¶
We have an Artec Eva Scanner in the lab. This structured-light 3D scanner is the ideal choice for making quick, textured, and accurate 3D models of medium-sized objects such as a human bust, an alloy wheel, or a motorcycle exhaust system. It scans quickly, capturing precise measurements in high resolution. Light, fast, and versatile, Eva is our most popular scanner and a market leader in handheld 3D scanners. Based on safe-to-use structured-light scanning technology, it is an excellent all-around solution for capturing objects of almost any kind, including objects with black and shiny surfaces.
Techical specs of Artec Eva Scanner:¶
- 3D accuracy - Up to 0.1 mm
- 3D resolution - Up to 0.2 mm
- Object size - Starting from 10 cm
- Full-color scanning - Yes
- Target-free tracking - Hybrid geometry and color based
- 3D reconstruction rate - Up to 16 FPS
- Output formats - All popular formats, including STL, OBJ, and PLY.
Procedure for using the Artec Eva 3D scanner¶
- Prepare the Scanner: Set up and calibrate the Artec Eva 3D scanner according to the manufacturer’s instructions. Connect it to a computer and launch the Artec Studio software. Ensure the scanner is connected to computer via USB and powered on. Place the object in the scanning area, ensuring it’s well-lit and stable.
- Open Artec Studio software and choose Autopilot mode, which streamlines the scanning process.
- Initiate the scan, the software guides through the scanning process, capturing data automatically.
- Monitor the scanning progress on the computer screen. Adjust as needed to ensure complete coverage of the object.
- Once scanning is complete, review the scanned data. Click on the Auto Pilot where first thing to do is auto allign followed by other setup which will be done automatically by clicking next.
- After completion of Autopilot, use the editor tool to remove any unwanted parts from the scan.
- Use the fix holes tool to patch any gaps or holes in the scanned model and Texture to apply textures to the scanned model. This adds visual detail to the model, enhancing its realism.
- Save the finalized 3D scan data in the desired file format (e.g., .OBJ, .STL) for further use or export.
- Clean the scanning area and properly store the equipment for future use.
3D Scanning Process with KIRI Engine¶
To scan my favourite marvel character ‘Hulk” , I used the KIRI Engine app on my phone.
- Open the Kiri App and click on the plus sign icon. Place Hulk on a rotating chair and capture photos from all angles upto 70.
- Upload the images and wait for some time and then wait when processing.
- After successful model generation is confirm, download and check how it looks after scanning.
- For post-processing the scan, I utilized Blender to clean up the files for 3D printing.
