HOMEBREW My Homebrew 3D Scanner By Tim Anderson
Imagine a camera that captures the
shapes of things, and a printer that prints out
those shapes. We live in a world where paper is flat
and computer displays are flat, but pretty much
everything else is 3D. So how about taking photography into the third dimension? Not just as a visual
illusion, but as a way to record three-dimensional
shapes and then print them out as actual objects.
Years ago, friends and I got excited about this and
built 3D scanners and 3D printers. We started a
company called Z Corp. to make 3D printers, and
these days there’s a printer in every major town.
3D scanners are not so common, however, which is
strange because you can build one in a few minutes.
This is Kenny Jensen, sitting on a stool that slowly
rotates at a constant speed. It has an electric,
motorized antenna rotor bolted to the seat post.
A bubble level ensures that the axis of rotation is
vertical. A laser pointer shines through the stem of
a wineglass, which spreads the beam into a vertical
line on his face. The wineglass stem is a cylindrical
lens that spreads the beam in only one axis.
A camcorder looks at this green line from an angle
and sees a wiggly, green line silhouette. The computer
192 Make: Volume 14
records the video frames of this wiggly green line.
(The nylon sock holds his hair down. Hair is too fine
for the beam, and shows up as spikes.)
How do we turn all those video frames of squiggly
lines into a 3D model? Jensen wrote a MATLAB
script that does it. (You can see the step-by-step
instructions on Instructables at makezine.com/
go/3Dscanner, including the script.) The software
does some simple trigonometry to calculate the
distance to each point on the surface of the face,
then assembles the 3D model. There’s commercial
software that does the same thing, as well as a
rapidly growing collection of free utilities.
Once I had 3D models of myself, I proceeded to
3D-print them and then cast those parts in metal.
I made some titanium toy soldiers of myself. I also
made self-portrait cremation urn bookends of my
head. I thought they were pretty creepy, but my
mom loved them. She’s still got them on her mantel.
Video of the scanner in action:
Tim Anderson is a columnist for MAKE and a founder of Z Corp.
Photograph by Tim Anderson