DIY
IMAGING
Stepper right up:
Webcam-software-plotter
system draws your
likeness While U Wait.
SCRIBBLER BOT
Homemade two-axis plotter finds work as
a caricature artist. By Douglas McDonald
Photography by Douglas McDonald
The Scribbler Bot is a software-hardware system Plotting the Course
that converts a digital image into a stylized physical The first step in building the Scribbler Bot was
drawing. The software component converts a finding a way to control and move the stylus
webcam snapshot into a line drawing that consists along two axes. I needed a system that could keep
of a dense network of “scribble lines.” It then exports track of where on the page the stylus has been, is
this vector-based representation as a set of currently, and needs to go, while correlating these
point-by-point motor commands to the system’s locations to their analogous positions in the
hardware component: a homemade orthogonal image’s digital representation.
plotter. The plotter creates the drawing using a Creating this setup is possible by using stepper
pen, pencil, or any other medium you can attach motors — which move in discrete, programmable
with a zip tie. amounts — and a dual-motor control system. After
This article focuses on building the plotter, some searching, I decided to use the A200-SMC
which moves a stylus along both x- and y-axes system from Stepper Control (
steppercontrol.com).
— in contrast to a printer, which moves its print The A200 includes a hardware controller board
head along one axis. Orthogonal plotters, aka that connects to a Windows machine via parallel
flatbed plotters, are often used for full-sized port, and software (which I did not use) that
engineering and architectural drawings. commands the controller board from a PC.
