Assignment 5: 3D Scanning and Printing

Test the design rules for your printer(s):
When I started to find information about the quality of 3D printers I came across an article telling about designing a test object for 3D printing. We printed the test object with our two 3D printers: Leapfrog and Stratasys 380mc. In the following pictures the Stratasys print is the left one with the support material (white) not dissolved yet.
  

3D Printer	Nozzle diameter	Layer height	Material
Stratasys 380mc	0,25 mm	0,25	ABS
Leapfrog	0,35 mm	0,3	PLA

The Stratasys print was with enhanced surface.

The result is as follows: the surface of the Stratasys print is smoother and the overall quality of the Stratasys print is better. However, the fine detail shown in the second but last picture with narrow slots and fingers is much better in the object printed with Leapfrog. In the Leapfrog print there are discontinuities caused by stuck filament. We had to manually rotate the filament spool when it seemed to jerk. The last picture pair shows how the bridge came out perfect with Stratasys using support.






Design and 3D print an object (small, few cm) that could not be made subtractively

For the object that could not be made subtractively I designed a thingamajig, that is made of a hollow box with two holes in opposite sides, with a sphere bigger than the holes inside the box. There is also a rod attached to the sphere, as shown in the picture below.


The design process of the thingamajic is presented below:
1. create the basic solids: 20x20x20 mm cube, 16x16x16 mm cube, cylinder with 5 mm radius and 30 mm length, cylinder with 4.5 mm radius and 20 mm length, sphere with 7 mm radius.
2. align the 20x20x20 cube with the cylinder of 5 mm radius and 30 mm length
3. subtract cylinder from cube to create a cube with a hole
4. align the cube with a hole with the smaller cube to make a hollow cube with a hole
5. align the sphere with hollow cube with a hole
6. stick the smaller cylinder to the previous combination

I can't see, how the solid sphere can be machined inside the hollow cube with holes smaller than the sphere.





3D scan an object (and optionally print it)

At first I tried to use Sense , but without any luck. My Windows 7 laptop didn't recognize the device. The I tested it with a new desktop Windows 7 PC. Now I  managed to capture something, but  it wasn't recognizable, and it made no sense. Then I tried Autodesk 123D Catch with my Android phone. The initial result was disappointing. Next I started using a compact system camera. At this point I also read the 123D Catch quick start guide. To succeed, the pictures must have  a common reference, such as a newspaper or sticky notes with varying shapes/patterns. I took 28 photographs from different angles and heights.

3D Scanning process:

I started by opening 123D Catch and creating a new capture.


Then select photos:


and Create Project:



Photos are uploaded to Autodesk server:




Then wait for an hour or so for the processing:



And a 3D-view appears:



Use the Lasso tool to clean the model:



And there the bird is without the newspaper:


Choose mesh quality:


and export the scan as OBJ-file



And import it into MeshMixer:


Analysis -> Inspector shows errors:



And repairs them:



Edit -> Make Solid converts mesh to a solid.



Press Accept and you get the fixed solid:


Which can be exported to 123D Design or as an STL-file for example.


In a Windows 10 computer the OBJ-file can be opened with 3D Builder:


Which asks to repair the model (see the wrench): Sorry about the Finnish user interface:).



Click the wrench and get the repaired model, which can then be saved for example as an STL-file:


I imported the STL-files generated by MeshMixer and 3D Builder to 123D Design and scaled them to about actual design. However, I decided to print it very small to conserve filament.




I sliced the object for printing with Stratasys Insight. I got a warning for small size.





The flag symbol does all remaining processing. One can select the interior filling, surface finish and support style. Otherwise, it is a straightforward process.


There was something wrong with the model:


But Insight corrected the model, and the slices to be 3D printed look like this:



I tested the slicing with the object corrected and made to STL with Microsoft 3D Builder. This time I chose Sparse interior style, Enhanced surface and Break-away support.


This time got no errors:


The button Build sends the data to the printer:



The printer Control Center lets you position the print.



Just install a clean build plate into the 3D-printer, and press the PLAY button (between PAUSE and STOP)...



 
And the new nestling looks like this.


Files:
Bird
STL from 3D Builder
Thingamajic
Thingamajig design process


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