5. 3D Scanning and Printing¶
Group Assignment:
- test the design rules for your 3D printer(s)
Individual Assignment:
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design and 3D print an object (small, few cm3, limited by printer time) that could not be made subtractively
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3D scan an object (and optionally print it)
Download Design Files¶
Click here to download my design files folder and also Click here to download my interlocking mobius ring Fusion 360 file
Group Work Reflection¶
For this week’s group assignment we tested the design rules for our 3D printer. I learned about the different design rules for a 3D printer that I had never even considered before. It was interesting to see how the limits of the 3D printer varied between different aspects of the print. For example, the bridging we did all successfully printed were able to range ~23 mm in length before we really saw any quality difference. Comparatively, the range in size possible for the subtractive wall thickness was extremely small. Only one of them actually came out properly. Furthermore, I saw how important dividing up work is and how efficient it is when you properly implement this. I feel the group work was well split up and we enjoyed working together!
Designing and 3D Printing¶
The individual assignment for this week challenged us to design and print a 3D object that cannot be made subtractively.
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Subtractive Manufacturing: removes material from already existing objects
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Additive Manufacturing: build objects by adding material
Designing¶
The 3D object I decided to make was an interlocked mobius ring. I used this tutorial: MAD’ About Designs Tutorial.
I first opened a new design in Fusion360. I then set the document settings units to cm. Next I created a new sketch on the top plane. Under the create tab I went to arc and selected center point arc. I selected the origin as the center point, set the diameter as 5 cm, and the angle as 180 degrees. I then clicked finish sketch. Next I made a new sketch and selected the front plane. I made two vertical lines 3 cm long, clicked midpoint constraint, selected one of the lines, and selected the end point of the line of the previous sketch. I did the same for the other line. Under create I went to arc and selected center point arc. I selected the right end point of the horizontal line as the center and made the radius 1.125 cm and the angle 180 degrees. I then clicked finish sketch. Next I switched from the solid tab to surface. Under create I selected the sweep command. I selected the left line (the one without the semi-circle attached to it) and selected the path as the arc that connects the two 3 cm lines. I set the twist angle to -90 degrees and kept the operations as perpendicular and new body. I then clicked ok. Under create, I selected thicken, selected the surface, and set the thickness to 0.5 cm, the direction to symmetric, and operation to new body. Under the sketch visibility tab, I set Sketch 2 to visible. I then switched to the solid tab and under create selected revolve. The profile is the semicircle of sketch two. I then selected the vertical line attached to the semicircle for the axis and set type to full and operation to new body. After clicking ok, I went and hid Sketch 2. Under create I went to pattern and selected path. I selected features for the pattern type and made the first sketch visible, selected the arc for the path. I then made the distance 15.708 cm, quantity 7, start point 0.0, distance type extent, direction as one direction, orientation as identical, compute option as adjust, and checked the suppress box. I then clicked ok and hid the first sketch. Under modify I selected combine and set the target body to the curved semi-circle rectangle (everything but the 7 spheres), selected the 7 spheres for the tool bodies, set operation to cut, and clicked ok. Under modify I selected the fillet tool and set type to fillet and selected the 4 outermost long edges and set the size the fillet size to 0.15 cm. I then used the fillet tool again and selected the top and bottom edges of the circles and semicircles with a size of 0.15 cm. Next, I clicked move/copy, selected the whole design, set pivot to the origin, checked create copy, and then pulled the z axis out and entered 180 degrees. Under modify I again selected the combine tool, selected one side of the design, set operation to join, selected the other side of the design, and clicked ok. I selected move/copy again, clicked the whole design, set pivot to the origin, checked create copy, and set the y-angle to 180/12 degrees.
I then saved the file and exported it as a stl file. I opened PrusaSlicer and imported the file. I selected the following settings:
Print Settings: 0.20mm STRUCTURAL
Filament: Prusament PLA
Printer: Original Prusa MINI & MINI +
Supports: On build plate only
Infill: 15%
X Size: 2.8676”
Y Size: 2.8166”
Z Size: 0.6793”
For the Print Settings, I used the following values and included a brief description of what the setting means:
Layer Height
Layer height: 0.2 mm
- Controls the height (and thus the total number) of slices/layers; thinner layers give better accuracy but take more time to print
Vertical Shells
Perimeters: 1 mm
- Sets the number of perimeters to generate for each layer
Horizontal Shells
Solid layers: Top = 5; Bottom = 4
Minimum shell thickness: Top = 0.7 mm; Bottom = 0.5 mm
Infill
Fill density: 15%
- Density of internal infill
Fill pattern: Grid
- Fill pattern for general low-density infill
Top fill pattern: Monotonic Lines
Bottom fill pattern: Monotonic
** Reducing printing time**
Combine infill every: 1 layer
- Allows to combine infill and speed up your print by extruding thicker infill layers while preserving thin perimeters and accuracy
I then clicked apply and exported the file as a gcode.
I imported the gcode file in OctoPrint and, after ensuring the printer bed was clean (I used alochol on a paper towel to wipe it off) and the printer was ready to use, I clicked print on my file.
Final Design:
I didn’t have any issues making or printing the design, it turned out quite nicely on my first print!
3D Scanning¶
Polycam¶
To use Polycam for 3D scanning, I first downloaded the app on my phone. Next, I opened the app. It asks you to start a free Polycam Pro trial, however, I decided to use the free, standard version to see how the basic app works.
It will then pop up with a video tutorial. It suggests you…
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Pick a good subject
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Photograph all angles
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Take 50-100 images
I will add that using a white background and having good lighting are very helpful for getting a good scan.
Next, the 3D scanning interface will pop up.
This is the object I chose to scan, my mouse:
You can either hold the camera still and tap the record button or tap the “+” shutter button to record frames. I chose the former.
Below are pictures of my final 3D model:
I took ~50 photos to achieve this scan. This was my first attempt and it turned out fairly well.
I cropped the model so that less of the surface I scanned the mouse on was included in the final 3D model. It was difficult to scan without getting the table in the model, which I consider a limitation of Polycam. There are no other features of Polycam that would allow me to remove the table besides cropping it, unfortunately. Maybe if there was an ability to scan with a green screen background I could have removed the table from the scan.
More on limitations of Polycam, the only file type you can export from Polycam’s free version is GLTF or as an image or video. Polycam Pro users can export in file types: OBJ, FBX, DAE, STL, USDZ, PLY, LAS, PTS, XYZ, DXF, or as a blueprint.
Free edits you can make to the model include: process, crop, measure, video, background, extend, rotate, and rescale. There are also many ways to view your model in the Polycam app/website.
Overall, Polycam was extremely easy to use and produced a decent 3D model of my mouse. For being free, I’d say it’s worth a try, however, I don’t think you could produce many high quality 3D prints from this scanner.
Creality Scan¶
Before using Creality Scan, I watched this Creality Scan tutorial that Collin Kanofsky recomended. I then downloaded the Creality Scan app on my phone and prepared the physical scanner; you can buy a CR-Scan Ferret Pro 3D Scanner from Amazon here. Next, I read the quick start guide included with the scanner. The scanner comes with a: rechargeable handle, CR-Scan Ferret Pro Scanner, wireless bridge, tripod, phone holder, power cable for wireless bridge, data cable for wireless bridge, quick mount kit, USB cable for smartphone and handle, USB cable for computer, type-C adapter, and a carrying case.
The system requires one of the following:
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a PC i5-Gen8 CPU and above, Windows10/11 (64-bit), and RAM 8G and above.
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Mac M1/M2 series processor, macOS Big Sur 11.7.7 and above, and RAM 8G and above.
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Android 10.0 and above and RAM 8G and above.
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iPhone11 and above, IOS13 and above, and RAM 4G and above.
Software required:
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For Windows and Mac: Creality
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For Android: Google Play
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IOS App Store
You can then either connect Ferret Pro to your PC via a USB cable or connect Ferret Pro to a Phone via Wi-Fi. I did the latter. I connected the phone holder, tripod, rechargable handle, wireless bridge, and CR-Scan Ferret Pro Scanner together. I then put my phone in the phone holder, connected the wireless bridge and scanner with the data cable, and connected the wireless bridge and my phone with the power cable.
The next step was to connect my phone to the wireless bridge via Wi-Fi. In theory you should:
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connect the wireless bridge to the scanner and rechargeable handle and wait a few seconds for the LED to turn blue.
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Go to your phone’s Wi-Fi setting, search for a network called “Ferret-XXXXXX” and connect to it.
Then, after a few seconds, your phone should be connected to the scanner. This, however, did not work for me. The network never showed up and my mac was not compatiable with the scanner. Thus, I was unable to use this scanner. If I had an android phone, I could have used a cable to connect to the scanner, however, I do not. This 3D scanner, in comparison to Polycam, was very hard to use.
Reflection¶
This week helped me to see the value in easy to use equipment and also how valuable 3D printing is to the design world as many things are not easy or possible to make subtractively.
References¶
Additive vs. Subtractive Manufacturing