3D scanning and printing


I. Design rules for our 3D printer(s)

Ultimakere 3 (Extended)

Precision/Orverhang test

A Precision/Orverhang test was performed on a Ultimaker3 3D printer and Cura slicer. The settings used are using are the preset standard settings for a normal quality print with PLA filament. Mainly:

For The Precision/Orverhang test we downloaded a small test file from thingiverse. It just took 40 min to print and gave very decent result

Precision/Orverhang test results: Tolerance/Precision test

A Tolerance/Precision test was performed on the Ultimaker3 Extended 3D printer and Cura slicer. We downloaded the Tolerance/Precision test file from thingiverse. The settings used are as for the previous test with PLA filament. The test features moving hinges of varying tolerances ranging from 0.38mm up to 0.635mm. It also features thin walls and wells ranging down to 0.016mm

Tolerance/Precision test results:

I'm sceptical about the results of the tolerance test. I've used a different tolerance test for the Flashforge 3D printer (next paragraph) and the clearance was ok for 0.4 and 0.5mm. This could be a design issue. I'm not sure the design of this test is not proper for tolerance. So I would say the tolerance test was inconclusive.

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Flashforge Adventurer3

We performed Precision/Ovwehang and a tolerance test on a Flashforge Adventurer3. This machine has a dedicated slicer called Flashprint. We also used PLA.

Precision/Ovwehang test

In this case we tested the print on the High quality preset setting, because the standard settings gave poor results for a part I had previously tried. The settings are mainly:

Precision/Ovwehang test results:

NB: Apparently the Ultimaker gives better results in precision even in normal quality. For tolerance we would have to make the same tolerance test with the Ultimaker to draw conclusions.

Tolerance test

For The tolerance test we downloaded another test file from thingiverse. It We tested the print on the standard quality preset setting with PLA filament. The print test tolerance for 0.1/0.15/0.2/0.25/0.3/0.4/0.5mm. The settings are mainly:

Tolerance test result: passed for 0.4/0.5mm
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II. Design and 3D print an object

A. Design Villarceau circles

I designed a toroidal shape based on the Villarceau circles. It is a well-known shape which is non trivial but very easy to draw. The Villarceau circles are a pair of circles obtained by the intersection of a torus and a plane that is tangent to the surface of the torus and cuts through it by it's center. The following screenshot illustrates the simple steps to design this topology:

  1. Sketch the profile of a torus and the intersecting plane (give thickness to the plane with an offset to create surface)
  2. Create volume by revolving the torus section around the central axis (construction line).
  3. Extrude the rectangular surface to create a board volume representing the intersecting plane
  4. Intersect the torus with the board to obtain a volume that resembles the Villarceau circles
  5. Create a circular pattern around the central axis to create the modal shapes

B. Printing with Flashforge

I first printed this model with the Adventurer3 in red PLA material and high quality settings (same as the settings tested in the precision/oerhang test). No support was needed, nor raft or brim.The Fusion drawing includes parameters to modifies the number of modes, the shape of the torus, its dimensions and the thickness of the wall. To generate the STL file on Fusion you just need to right-click on the name of the drawing (or component) that includes all the bodies to be printed, and select save as STL. Initially, I set the torus diameter at 50mm and the thickness at 1mm, but the STL file was to big and the printing time too long so I scaled it 70% on the slicer to reduce the printing time to 3 hours. So the walls printed were about 0.7mm and the torus diameter 35mm. It can be scaled down to 50% as I have tried to reduce the printing time to 1 hour but the quality of the result is poorer.


C. Printing with SLA 3D Printer – Form 2


I also printed the Villarceau circles with the Form 3 SLA 3D printer in clear V4 resin. The SLA (Stereolithography) technology is very different from the FDM technology used in the previous print. SLA 3D printers use a light source to trace the model on a liquid bed of resin. The part is printed upside down on the build platform. The dedicated slicer software for this 3D printer is Preform. The model was scaled down to 60% on the printer the slicer to bring printing time to 3 hours. The model had to be placed in an oblique position in the slicer to make the file printable, other wise the slicer signals the areas that are not printable by colouring them in red. Support was generated automatically by clicking the support button on the left of the screen. Then additional support was added manually around the week areas highlighted in red. This is done by clicking the edit button in the support window, and then placing vertices on the model on the spots below wich a support structure should be added. After printing post processing is needed to clean the part in a rubbing alcohol solution. The Preform file is available here

The steps to print with the SLA Form2 are:
  1. Create a stl file in a 3D CAD
  2. Open the stl file in PREFORM slicer
    (file menu> open)
  3. Select resin type
    (bottom bar> print settings> Material> Version)
  4. Adjust scale according to printing time
    (tool bar>size> scale)
  5. Adjust orientation to minimize sensitive areas (in red) to make the model printable
    (tool bar> orientation)
  6. Automaticaly generate support
    (tool bar>support> generate)
  7. Manualy adjust support to minimize sensitive areas
    (tool bar>support>edit)
  8. Load the selected resin tank in the 3D printer and start the machine
  9. Connect the computer and start the print
    (file menu> print> upload job)
  10. After printing remove object and place in cleaning solution
  11. Manualy remove the support element from model
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III. 3D scan an object


We used the "Scan In a Box" 3D scanner which has a dedicated software called IDEA. This scanner uses the optical triangulation concept with a laser light source and two cameras. The object I scanned is a plastic puppy I printed on the Falshforge 3D printer. I downloaded the design from Thingiverse. The 3D scanner construct 3D surfaces from the data collected by the two cameras, and the software allows to patch the different 3D images to construct a 3D file which reproduces the shape we've scanned. You need to take many shots of an object in different orientations to reproduce the full object. The steps to do this are:

  1. Place the object on a black backgroud
  2. Open the software and turn on the camera
  3. Click 3D scan to capture the 1st 3D image
  4. Slightly change the orientation of the object and scan again
  5. Repeate this operation until the object has been fully revolved
  6. After revolving the object around one axis, revolve it around another axis
  7. With all the 3D images collected you can start constructing the 3D object
  8. At this point you wanna save the project
  9. In the top toolbar click Activate manual alignment
  10. The scanned images are now in two lists (fixed and floating) and there are three windows: for the fixed image, the floating image, and the combined image.
  11. Select the first 3D image in the fixed list in the alignment set
  12. Select the second 3D image in the floating list in the alignment set
  13. Select 3 point on the fixed 3D image
  14. Select 3 point on the floating 3D image in the vicinity of the points previously selected
  15. In the third window the two images will be superposed according to the points selected
  16. If the superposition is close enough click align
  17. If the superposition is a match click next and select the next image in the floating object list
  18. After completing this process the 3D object should be fully built
  19. If it is not, click ok, save, and take more scans targeting the missing areas
  20. Activate manual alignment again
  21. In the fixed objects list select all the object previously aligned
  22. In the floating object list select the new scans not yet aligned an align them one by one
  23. Once this process is completed and the object is fully built, create mesh by clicking the pyramid symbol
  24. Fix the imperfections using the processing tools to fill holes and smooth the surface
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