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Week 05: 3D Scanning and Printing

Learning Outcomes

  • Identify the advantages and limitations of 3D printing
  • Apply design methods and production processes to show understanding of 3D printing
  • Demonstrate how scanning technology can be used to digitize objects

Group Assignment

What I Learned from Testing the 3D Printers

For the group assignment, we used a premade all-in-one test print from Thingiverse and each sent it to a different printer — we tested six total: a Bambu X1 Carbon, A1 Mini, A1, P1S, an Anycubic Kobra, and a Prusa MK3S. We chose this file because it covered a lot of areas in a short amount of print time.

Key Takeaways:

  • Bridging was solid across all printers — every one succeeded up to 25mm (the test's max).
  • Overhangs varied — the X1 Carbon and A1 Mini handled up to 70–75° before failing, while the A1 and Anycubic Kobra started failing around 45–50°.
  • Stringing was nonexistent on the two printers using Bambu-brand filament, while all others showed minor to major stringing.
  • Tolerance showed all printers print holes slightly undersized (e.g., 8mm holes measured 7.5–8.0mm), which is important to account for when designing parts that need to fit together.
  • Dimensional accuracy had most measurements within ~0.2mm of 10mm. Not bad.

Individual Assignment

Design Concept: Print-in-Place Objects

The goal was to design and 3D print an object that could not be easily made subtractively (for example, with CNC milling). I found several print-in-place tutorials that demonstrated the capabilities of additive manufacturing. Per Claude AI, print-in-place mechanisms contain captive, interlocking parts that are fabricated as a single unit — no assembly required. A CNC mill cannot produce these because:
- Enclosed/captive parts: A mill cannot reach inside a closed geometry to cut internal moving parts
- Interlocking geometry: Linked rings, nested spheres, or enclosed bearings require material to surround other material — impossible with purely subtractive methods
- No assembly: The parts come off the printer already connected and functional, with clearance gaps that allow movement

Exploration Prints

Before creating my own design, I printed several existing models to learn print-in-place principles and understand how clearance, orientation, and support settings affect the results.

Phone Holder

I found a great tutorial from What Make Art YouTube site and he has several great tutorials about how to create print in place items. This video was only around 9 minutes. I thought initially he was going to go very fast, but it was a nice paced tutorial that I was able to duplicate with no issues. Shocking.
I started with a new sketch that include a couple of rectangles and a circle and extruded them. For some reason I didn't start getting screenshots until it was already extruded. Also the documentation is sparse on this exercise, but honestly I just need a break on this one. 1

2
4
5

Just look at that clearance...
6

Mirror it!
7

Where do I want to mirror it?? On that highlighted plane...
10

Alright! Looks pretty good and not too much cursing involved in the making of this object.
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Let's create a new sketch and make the shape below. That is the beginning of one half of our phone holder...
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Extrude it!
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Mirror and combine!
mirror
combine

Fillet!
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Final product! No assembly required!
phoneholder

## Files

File Description
Phone Holder Fusion file
Phone Holder stl file

Ball-in-Cube (First Attempt)

One of my tasks is to design something. It has to be something simple. That's not Fab Academy's requirement. That is my requirement. My skillset is still in the baby crawling stage. I did find a tutorial with a sphere inside of a cube. I will make an attempt to design one on my own first and then, if needed, I will tackle the tutorial.

  1. Start a new sketch on the Top plane
  2. Press R (2 point rectangle)
  3. Snap to the origin
  4. Set dimensions to 20 × 20 mm (press Tab to toggle between width and height) rec
  5. Press Enter -> Finish Sketch

  6. Press E to Extrude and set dimension to 20mm extrude

  7. Start a new sketch on one side of the cube and add a circle. Press E for extrude and cut out the circle.
    extrude

  8. Repeat that step until all sides have a hole cut through it.

  9. Click Create sphere. Type 14mm for the diameter.
    extrude

  10. Select the sphere and click Move icon and drag it inside the cube
    extrude
  11. Select File -> Export, choose stl as the file type and choose the file location. Click Export
  12. Open Bambu Studio
  13. Click File -> Import and chose the stl file created
  14. Click Preview -> Support
  15. Click normal(manual) under Type
  16. Check On build plate only
  17. Click Slice plate -> Print plate

Per Claude AI, print-in-place designs should ideally be designed to print without supports. After researching it looked like the ball would need a small amount of support or it would not be stable for printing. Guess what? It was true.

ball

Ball-in-Cube (Second Attempt)

As promised here is the second attempt, but this time with a tutorial. So basically this time it should print successfully.

Source: Fusion Fundamentals — MJ (YouTube)

Disclaimer: The instructions below were created by Claude AI from the YouTube transcript. I added the parameters and the screenshots.

Step 0: Set up Parameters

  1. Click the + sign and type "cube" in name and "30mm" in value
  2. Click the + sign and type "circle" in name and "cube+20" in value
  3. Click the + sign and type "small_circle" in name and "cube-20" in value
  4. Click OK
    0

Step 1: Create the Cube

  1. Start a new sketch on the Top plane
  2. Press S (shortcut menu) -> type Center -> select Center Rectangle
  3. Snap to the origin
  4. Set dimensions to cube × cube mm (press Tab to toggle between width and height)
  5. Press Enter -> Finish Sketch
  6. Press E to Extrude
  7. Change direction from One Side to Symmetric
  8. Enter cube/2 -> this extrudes 15 mm in each direction for a total height of 30 mm

2
A solid 30 × 30 × 30 mm cube centered on the origin.

Step 2: Create the Revolve Sketch Profiles

  1. Hide the cube body (click the eye icon in the browser)
  2. Start a new sketch on the Front plane
  3. Show the cube body again so you can see the reference
  4. Press C -> draw a Center Diameter Circle at the origin
    • First circle: cube + 20 diameter (outer cutout boundary)
    • Second circle: cube - 20 diameter (matches the cube edge size)
  5. Press L -> draw a vertical line through the center of the circles, top to bottom
    • This splits the circles into left and right halves
  6. Press T (Trim tool) -> trim away the left halves of both semicircles
  7. Finish Sketch

Result: Two right-side semicircle profiles — a larger outer one (50 mm) and a smaller inner one (10 mm).

Step 3: Revolve Cut — Hollow Out the Cube

  1. Go to Create -> Revolve
  2. Select both profiles (the area between the 30 mm and 50 mm arcs)
  3. Set the Revolve Axis to the Y axis
  4. Operation: Cut
  5. Click OK
    6
    A spherical cavity is carved out of the cube's interior.

Step 4: Revolve New Body — Create the Sphere

  1. Turn the sketch back on (visibility)
  2. Go to Create -> Revolve
    7
  3. Select only the inner profile (the mm semicircle area)
  4. Set the Revolve Axis to the Y axis
  5. Operation: New Body
  6. Click OK

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A sphere sitting inside the hollowed-out cube as a separate body.

Step 5: Export as STL

  1. Go to File -> Export
  2. Choose a save location
  3. Set file type to STL
  4. Export

Step 6: Slicer Setup and Printing

Slicer Settings (Bambu — PLA)

Setting Value
Material PLA
Infill Density 15%
Supports Manual (painted)

9
First attempt to print without any supports because I felt lucky (and I thought a true Print-in-Place didn't need supports)

Adding Supports

As we all know, the sphere would not adhere to the bed as seen in the above photo and it ended up being a tiny spaghetti ball. I found where I could add normal auto supports with a setting "On build plate only" that I checked. It worked perfectly this time. Total print time was 33 minutes and 43 seconds.

Final Print

final

Key Concepts

  • Symmetric Extrude — Extrudes equally in both directions from the sketch plane, keeping the geometry centered
  • Revolve Cut vs. Revolve New Body — Cut removes material from an existing body; New Body creates an independent solid
  • Print-in-Place — A single print that produces interlocking or trapped parts without assembly
  • Manual Support Painting — Targeted supports only where needed, rather than auto-generated supports everywhere

Design Files

File Description
ballincube.stl Exported STL for printing
ballincube.f3d Fusion 360 source file

3D Scanning

Scanning Setup

I set up a DIY scanning station using:

  • Turntable: Lazy Susan for rotating the object
  • Background: Black background
  • Lighting: room lighting
  • Scanning tool: Polycam app on iPhone
  • Object scanned: Mountain Dew can

mountaindew

Scanning Process

  1. Placed the Mountain Dew can on the lazy susan
  2. Set up background and lighting
  3. Used the Polycam app to capture images of the can from multiple angles while rotating the turntable
  4. Polycam processed the images using photogrammetry to create a 3D model

scan

Scan Result

The scan of the Mountain Dew can did not come out particularly well. The top of the can was crumpled.
MountainDew

MountainDew
A thing of beauty

Lessons Learned:

  • Shiny/reflective surfaces (like an aluminum can) are difficult for photogrammetry — the reflections can cause confusion
  • Future improvements could include: scanning a matte/textured object, using more consistent lighting, taking more overlapping photos

Files

File Description
MountainDew stl file Exported STL for printing

Reflection

This week I learned the fundamental strengths and limitations of 3D printing compared to subtractive manufacturing. Key takeaways:

  • Print-in-place designs demonstrate a capability unique to additive manufacturing — creating assembled mechanisms in a single print
  • Clearance is critical — the group tolerance testing directly informed my design parameter of 0.4 mm, without which the phone holder and sphere inside the cube would have fused together
  • Supports for print-in-place parts — as I experienced with the ball-in-cube, I need a little support so there could be a successful print
  • 3D scanning with photogrammetry works best on matte, textured objects — reflective surfaces like aluminum cans are challenging