5. 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)

Individual assignment: - Design and 3D print an object (small, few cm3, limited by printer time) that could not be easily made subtractively - 3D scan an object (and optionally print it)

Group assignment¶

Testing 3D Printer Design Rules（bambu P1S）¶

It is crucial to test your 3D printer’s design rules. For example: Printing 60° overhangs without prior testing may cause material sagging that contaminates the model. I am using Bambu printer P1S CC, the software is bambu studio.

1. Overhang Limits¶

Print test models with graduated overhang angles,
Determine the maximum unsupported angle.

I guess that objects with an inclination of more than 45 degrees are easy to print, and less than 45 degrees are prone to problems, so I tested the range between 40° and 60 degrees. I wanted to print all the parts on one object, and I thought of the shape of a flower. This is my first version of the design.

After testing, I found that all inclined walls from 40 degrees to 60 degrees can be printed smoothly.

So I designed the second version. This time I used a simple wall test with an inclination angle of 20°~45°.

This time, I found that the printing was very poor at 20° and 25°, and the surface was very smooth at the tilt angle after 30°. Therefore, the overhang angle should be above 30 degrees, and no support is required.

2. Bridging Capability¶

Identify maximum bridgeable span without supports
Validate horizontal bridging quality

I set the test range of the horizontal bridge span to 5MM-30MM.

After printing tests, 5mm and 10mm have better effects. Although horizontal bridges exceeding 15MM can be printed, they are uneven and the bottom surface of the bridge sags.

3. Minimum Wall Thickness¶

Establish thinnest printable vertical walls
Test structural integrity of thin features

The thicker the wall, the easier it is to print successfully. In order to test the thinnest wall that can be printed, the thickness range of my test this time is 0.2mm-1MM.

After testing, it was found that walls with a thickness of 0.2mm-0.4mm could not be printed, and walls with a thickness of 0.5mm could be printed, but they were very fragile and easily broken. Walls with a thickness of 0.6mm and above were very strong.

4. Feature Resolution¶

Verify smallest legible text/embossing details
Check dimensional accuracy of micro-features

I want to test the minimum thickness (height and depth) that can be printed by text, the thickness range is 0.1-1mm. Each number represents the height or depth. height%20and%20depth.jpg

After testing, I found that the stretch height of 0.1mm-0.3mm is not very obvious, and the stretch merging quality of ≥0.4mm is very good. The stretch cutting depth of 0.1-0.4 is not very obvious, and the stretch cutting depth of ≥0.5mm is of good quality. height%20and%20depth.jpg

Individual assignment:¶

1. Design and 3D print an object¶

I experienced a terrible git error. I finished the 3D design part and updated the document with git add. But I found that some pictures needed to be resized. I resized the pictures and sent git commit and git push. As a result, git had an error and could not upload the file. I searched Deepseek for the method and followed the instructions below to repair GIT，After various attempts, I was able to successfully upload the document, but the content went back to 3 hours ago. All the text and pictures I just completed disappeared. It was terrible.

This is a 3D model I designed. I originally wanted to make a headband, but I didn’t know how to model, so I made a simple cup.

1.1 Create a cylinder

1.2 Create a circle on top of the cylinder and use a circular array to form many circles around the cylinder. Finally, stretch these circles.
3Dprint3+4.jpg

1.3 Create a sketch profile at the bottom of the cylinder and rotate it once to get a new entity.

1.4 Modify the entity by shelling and filleting.

1.5 Add text and engrave it on the surface of the object through embossing.

1.6 Set the printing parameters in bambu studio and print the items.

2. scan an object¶

This week I started my 3D scanning learning using the professional 3D scanning device revopoint pop2. The device is easy to use and the results are amazing.
Note: Transparent or reflective objects are difficult to scan.

There is an important information to know before scanning: objects with obvious features can be merged by features, but objects with similar appearance structures can be fused by marker points, and using the marker point fusion method, only two models can be merged.

2.1 First, you need to download the computer software Revo Scan 5.

2.2 Connect the scanner to the computer and power on the turntable. Connect the device in the software, create a new project file, and name the file.

2.3 Scan Settings: Set scanning parameters: turn on automatic exposure, aim the RGB camera at the center of the object, and set the scanning scene according to your needs.

2.4 Select the models separately and click Point Cloud Fusion. Cloud Fusion.jpg

2.5 You can also modify the model. Select the tool on the right, select the redundant parts of the model, and delete them.

2.6 Merge Model: After clicking Merge, select the model file to be merged, then click Feature Merge, Preview the Alignment, and finally Generate Model. The 2 models to be merged had to have ≥10% overlap.

2.7 Click one click edit to generate mesh and point cloud models. one click edit.jpg

2.8 Modify the model

Automatic hole filling: Click Fill Hole, select Plane/Curved Hole Filling, click Delete, the software will automatically detect the hole and display it with a green edge. Select the hole (multiple selections are allowed), click Apply, and the hole will be automatically sealed.
Click Isolate to automatically detect parts that may not belong to the model, select them and delete them.

2.9 Select the merged model, right-click or click the toolbar above to export the model, and you can choose different formats to save the file.

2.10 Finally, edit the model in other software (such as blender) to make it the shape you want. Then print it out.

I made some mistakes when merging models. For example, for models with obvious features, you can get a perfect model by just clicking on the features and previewing the merge effect, but I chose Manual alignment and then manually selected several locations to merge.

Tips learned from failure

Secondly: If you want to use Manual alignment to merge, I think using the manufacturer’s specific materials may work better. I tried to mark with a marker, but in the scan, a hole appeared where the marker marked.

3D design, printing and 3D scanning are all fun, and you can create objects that you imagine. This week has passed really quickly. I only learned simple scanning skills. Next, I also want to scan my own portrait and other objects, and I hope I can create more interesting products.