ROBOTRUCK

ROBOTRUCK LIVES!!!
I have been accumulating Fisher-Price Powerwheels vehicles
for some time now as a potential source of drives for 12 or 30
pound robots. For Halloween of 2003, I had chased kids
around the yard with my 60 pound robot S TONE AXE. For
Halloween 2004 I decided to animate one of the Powerwheels
in my collection. I added a Victor 883 speed control, a Hi-tec
805bb servo for the steering, and I used a couple of Futaba
servos to operate the hood and a Harley Davidson sound box.
I added a large toy robot driver and got the lights in the head
working. I used a Fisher-Price 6V SLA battery to power the
steering servo & Rx and a 12V 13Ah Hawker Genesis for the
drive motors. ROBOTRUCK turned out well as can be seen in
these videos:
1. CHOMP & GROWL
2. WHEELIE

There were a couple of Halloween costumes that probably
needed to be changed after ROBOTRUCK lunged from the
darkness illuminated only by a couple of tiki torches and
glowing robot eyes.

I had so much fun on Halloween that I decided to enter
ROBOTRUCK in the 2004 Stokesdale Christmas parade. I
dressed it up in Christmas attire as seen in the picture. I walked
far enough behind it that the crowd did not see me with my big
radio until ROBOTRUCK was past. I had an incredible amount
of fun with the kids and elderly. One little boy was watching
from a wheelchair and I nudged him slightly and then chomped
on part of his chair much to his delight. His mom mouthed a
silent "thank you" and I just beamed. One little girl screamed
as ROBOTRUCK approached and then tried to follow it in the
parade until retrieved by her parents.

In September of 2005, I took ROBOTRUCK to Atlanta for the
Dragon*Con Science Fiction Convention and entered it in the
parade that passes through downtown. It fit right in with the
legions of storm troopers, fairies, wizards, Klingons, Vulcans,
super heroes, you get the picture. It was a big hit with the
crowd. I had some driveability problems because of the slick
plastic wheels and the rear weight bias. On one dowhill
section, ROBOTRUCK would lock the rear wheels and spin
around backwards when I tried to slow down. This firmed up
my decision to revise the design.

In October of 2005, I made the following changes to
ROBOTRUCK:
1. 4-Wheel Drive - I removed the steering servo, welded the
steering links in the straight ahead position, installed two
additional motor/gearboxes on the front, an additional Victor
883 speed control and wired the motors and controls for skid
steer operation. I used smooth wheels from another
Powerwheels to minimize traction and therefore the power
required to steer.
2. Steerable head - To add a touch of realism to the robot
driver, I opened up the clearance in the neck pivot to reduce
the torque requirements and mounted a servo in the head with
a flexible shaft sticking downward and anchored in the torso. I
used a flexible shaft to protect the servo gears from the over
enthusiastic children with which ROBOTRUCK must deal.
3. New Eyes - ROBOTRUCK was originally equipped with tiny
yellowish incandescent bulbs in the eyes that were not visible
in daylight. While I was installing the head servo, I replaced the
eyes with bright red 10mm LEDs that were very visible and
even used less power than the bulbs they replaced.
4. Air Horns - One thing I have discovered with ROBOTRUCK
is that there are kids out there that are just rude and have not
been raised properly. They will grab, pull, and kick at
ROBOTRUCK in a destructive frenzy that really took me by
surprise. To answer this threat, I installed 105db air horns
controlled with a Team Delta RCE-220 control board. I used
the landing gear switch on my transmitter for activation.
5. General changes - To improve controllability, I relocated the
batteries from the rear to the center. I now use two 13Ah
Hawker SLAs in parallel to power everything with a 5V
regulator for the radio and controls. I made a hinged acrylic
cover for the truck bed and located the controls there. With the
relocated center of gravity, ROBOTRUCK will no longer
wheelie.

With these changes, ROBOTRUCK was a big hit during the
2005 Halloween evening. If the glowing red eyes and metallic
teeth didn't scare the kids, the air horns would.

I entered the revised ROBOTRUCK in the 2005 Stokesdale
and Greensboro Christmas Parades. Both were a real hoot.
The Greensboro parade was televised and I was interviewed
by Eric Chilton of WFMY, the local CBS affiliate. You can see
the interview by clicking here.