This document provides an overview of DIY 3D scanning techniques for 3D printing, including types of scanning methods and instructions for setting up Kinect and DAVID scanning. It also outlines the file preparation workflow needed to repair scanned files, including filling holes, smoothing, and fixing geometry issues, in order to produce a watertight STL file suitable for 3D printing.

1. DIY scanning for 3D printing: an
overview
Sophie Kahn, Natalia Krasnodebska
and Lauren Slowik

2. Why 3D scan?
3D scanning brings real-world
objects into the digital realm
-Save modeling time
-Scale up or down
-Modify or remix objects
-Output them in different
materials, using different
technologies (3D printing,
CNC milling, etc)

3. Types of 3D
scanning
-Laser line
-Structured light
-Photogrammetry
-Time-of-flight
-Contact

10. To create a
Kinect scanning
setup
-Office chair that spins
-Bright lamp
-Microsoft Kinect v1 or v2
-Kinect drivers and SDK
-Skanect software

11. DAVID structured light/laser
scanning

12. DAVID
laserscanner
You will need:
-Focusable laser diode and battery
pack, or laser level from a hardware
store
-Webcam: the higher res and faster
fps the better (I use The Imaging
Source)
-Printed calibration panels
-Cardboard/plywood
-Set square

13. DAVID
structured light
You will need:
-Pico projector
-Calibration panels
-Webcam (the higher-res and
higher fps, the better)
-Small desktop tripod
-Dual head for tripod
-Two rotating ball tripod mounts
-Turntable (optional but helpful)

14. -White spray paint or removable
spray powder (talc developing
spray, dry shampoo)
-White play-doh for registering
multiple scans
-Black spray paint
-Black painted blocks to serve as
props
-Helping hands tool
-Black velvet to mask out
background
Useful
accessories for
3D scanning
small objects:

15. Steps to make a
DAVID scan
-Set up calibration panels at 90
degrees, using a set square for
accuracy
-Calibrate camera
-Prepare and stabilize your object
-Scan in sweeps, rotating object
and flipping as needed
-Register scans in DAVID
Shapefusion
-Fuse surface and export

16. Repairing files for 3D print

17. What does a 3D printer
need in a file?
-File must be “watertight” (one solid form, no holes)
-File must have no geometry errors (all polygons
face same way, etc)
-File must be correct thickness
-File must be structurally sound

18. Workflow to
prep scan for
3D print
-Fill holes in scan file &
make solid (Meshmixer)
-Smooth and sculpt
(Meshmixer)
-Repair geometry
(Netfabb)
-Export .stl for printer
(Netfabb)

19. Repairing files with
Meshmixer

21. Fill holes in
Meshmixer:
Edit->Close Cracks
Edit->Make Solid

22. Smooth in
Meshmixer:
Edit->Brushes->Shrink
Smooth/Bubble
Smooth/RobustSmooth

23. Steps to repair
in Netfabb
Basic
-Fill any remaining holes using rt-
click->Fill Hole
-Remove unnecessary shells
-Run basic repair & apply
-Trim object and removed trimmed
parts if necessary
-Fix any bad geometry by deleting
and re-adding triangles
-Run basic repair one last time
-Export as .stl

26. Additional steps
in Netfabb Pro
-Wrap part surface if object is
severely corrupted
-Reduce triangle mesh to
<1,000,000 polygons
-Hollow model to desired wall
thickness
-Add drain holes using Boolean
operations
-Run wall thickness visualization to
check structural integrity