diy 3d scanning for 3d print - makerfest india

DIY scanning for 3D printing: an overview

Sophie Kahn, Natalia Krasnodebska and Lauren Slowik

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)

Types of 3D scanning

-Laser line

-Structured light

-Photogrammetry

-Time-of-flight

-Contact

To create a Kinect scanning

setup

-Office chair that spins

-Bright lamp

-Microsoft Kinect v1 or v2

-Kinect drivers and SDK

-Skanect software

DAVID structured light/laser scanning

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

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)

-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:

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

Repairing files for 3D print

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

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)

Repairing files with Meshmixer

Fill holes in Meshmixer:

Edit->Close CracksEdit->Make Solid

Smooth in Meshmixer:Edit->Brushes->Shrink

Smooth/Bubble Smooth/RobustSmooth

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

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