(^86) The Official Raspberry Pi Projects Book raspberrypi.org/magpi
hile well-known Pi
community member David
Pride admits that Nerf
guns hadn’t been invented when
he was a youngster, his interest
was sparked when he saw two
tables full of Nerf gear at a car boot
sale. “I started wondering whether
you could operate the trigger
mechanism with a servo – turns
out you can!”
Following some successful
experiments firing smaller, single-
shot Nerf guns using a servo, David
turned his attention to larger Nerf
Projects SHOWCASE
Say hello to David Pride’s Nerf-toting robot!
You have 20 seconds to comply...
t currently I
runs on 14 AA
batteries
The firing
mechanism
is mainly
3D-printed
David plans to
add a camera
He’ll upload
the STL files for
3D printing
FRED-209 is
sadly too big
for Pi Wars
Quick
Facts
The custom 3D-printed firing
mechanism shoots the foam
darts from a Nerf magazine
FRED-209
Built on a Rover 5 chassis,
the robot has caterpillar
tracks for extra grip
W
Wall-mounted alien
targets drop down
when shot by FRED-209
DAVID PRIDE
Currently studying for a PhD with the
OU, David is a well-known member of
the Pi community. Previous projects
include a Lego-sorting robot arm and
Connect 4-playing robot.
piandchips.co.uk
models. “[I] realised that there are
essentially two types: the pump
action ones and those which use
two flywheels to propel the dart.
I didn’t know exactly how the
mechanism worked until I actually
took one to bits!”
Initially, David simply strapped
an upside-down Nerf gun to the
top of his 2017 Pi Wars robot,
X-Bot. “I realised that this wasn’t
really going to cut it, so set about
designing and 3D-printing a
complete setup that I could mount
on top of a bot. It uses the original
Nerf flywheels, and the original
Nerf magazine which can hold six
darts. The rest is all 3D-printed. I
also designed a simple mechanism
to translate servo movement into
lateral movement to push the dart
into the launcher.”
During the two months of
evenings and weekends he
spent working on the project
over the summer, several design
changes were made. “The biggest
disappointment was that the
huge chunky motors I had didn’t
have enough torque to turn the