Charlie Joe's Christmas Wish
In the fall of 2000, Laurie T. called and said she was in a
jam. All the guys in her family are involved in one
way or another in drag racing. Her husband owns and
operates a drag racing team, her 11 year old son drives a
junior dragster, and her youngest, Charlie Joe is an avid fan
of legendary funny car driver John Force.
Six year old Charlie had come to her and stated that Santa
can make anything. And he was sure that if she
just asked, Santa could make a John Force funny car for him
to drive. Charlie has a number of battery powered
ride-on trucks, so he's no stranger to driving.
She tried to tell him that maybe some things were
beyond even Santa, but he was not to be dissuaded.
Laurie wondered if I was interested in being an elf.
I love a challenge, and am a race fan myself, so I accepted
the assignment.
The project began by surreptitiously making off with an old
Power Wheels® truck that had been sitting around in the
garage, unused for quite some time. Of course the day
after this long-forgotten toy came home with me, young
Charlie was grilling his Mom about the whereabouts of his
truck.
Shown here it has been partially dissected in order
to study the wiring and power system. At first the
wiring was baffling, seeming to double back upon itself.
But, with a good deal of help from my Father, who is
good with electronics, we figured it out and I stripped the
wiring, switches, batteries, motors, running gear and wheels
from the old truck.
The next step was to download and study photos of John
Force's funny car and produce working drawings to map out
the course ahead on paper. My original thought was to
build a scale model of the real funny car, with the wheel
diameter setting the scale ratio.
Unfortunately it wasn't until I got the chassis
layout and side view elevation all done that it occurred to
me that there was a problem. This "toy" is
intended to be a Christmas present. The weather around
Christmas is often a bit unpredictable. The T family
has a large family room in which the boys often ride their
large toys, but at almost 7 feet long, turning radius will be
a problem for indoor use.
So I re-designed it to be more of a caricature of a funny
car, with a more reasonable size and turning radius for
indoor use.
The first stage of actual construction was to build a
light weight but strong chassis. My solution was to
laminate up a frame work of 1¼" wide strips of
¼" baltic birch plywood. By alternating
strips that ran the full length with ones that ran full
width, a strong, stable lattice was achieved. Keeping
it light weight is very important so that the battery powered
motors won't be overloaded by weight of car and
passenger.
Once the chassis was ready, I added mounts for
steering gear and the drive motors and rear axle. The
"shock towers" are probably over-built, but I'd
prefer to make sure the steering gear can stand up to bumping
along in the back yard without that sickening crack
of a major suspension part giving up the ghost.
They're braced fore & aft and cross braces will be
installed as the ribbing is added in the nose section.
A compartment will be mounted between them to provide a
secure yet easy to access place to keep the 6 volt batteries
and their charger.
With most of the body ribs & stringers
installed, I flipped the chassis over to ease installing the
skirt supports and battery compartment belly pan and to give
the under side a thorough coat of sealant to help protect it.
The baltic birch ply is quite weather resistant, but I
prefer not to take chances. I decided to use a skirt
around the edge rather than setting the chassis that low to
help with ground clearance. This would not be a
concern if it was used only indoors or on the driveway, but
drag from grass and uneven ground could cause the motors to
overload and trip the breaker.
The body uses ribs and stringers like a model
airplane to keep the weight to a minimum yet provide a rigid,
sturdy frame for the skin. 1/4" Baltic Birch Ply
is used for all of these structures, with reinforcing blocks
made from shop scraps -- mostly poplar -- where additional
strength is needed. The polyurethane glue assures
great strength, but slows construction because all parts
installed must be securely clamped for 12 hours while the
glue catalyzes.
One side effect of this glue is that it foams out of
the joints as it sets up. Once hardened, the foam
trims away easily, but I must be vigilant and remove it
anywhere it would interfere with the fit of other parts.
With the rear fender wells bent into place, dash board mounts
and the firewall with it's attendant accelerator pedal
and wiring in place, it's starting to come together.
Rather than running the wiring underneath the floor
boards, I ran a length of 3/4" dowel through the table
saw to flatten an edge, then used a cove bit in the router
table to hollow it out. This tube runs from the fire
wall to the rear wheels like a transmission hump and conceals
the wires running to the motors on the rear wheels.
With the dash installed, the switches can be wired
and all systems tested before the body panels start going on.
My thanks to the Woltman Company for allowing me to
use their sublimation equipment to produce the 4 nifty gauges
used on the dash.
The steering gear from the original truck was
installed backward to that the tie rod is behind the front
wheels instead on in front. This was to necessary
because this car is about a foot longer than the truck was.
I had hoped to bend the metal parts of the tie rod and
steering rod and use the same direct connection used
originally, but found that this would not work out.
Instead I elected to go with the cable system shown.
It's more complex, but quite reliable.
The most difficult, complex curves are on the
nose of the car. So to deal with that, I constructed a
hollow nose cone from layers of basswood. Basswood is
very light weight and easy to carve and shape.
I'll use a rasp to rough out the shape, then sand with
successively finer grits to make a smooth surface.
The interior panels have been painted and installed,
Dash in place and all wiring secured, we are ready to start
fitting body panels.
The neighbors thought I was crazy when I set
up this "Witches Kettle" for steaming the plywood
that will become the skin of the car. Baltic birch
becomes quite pliable if soaked in very hot water for about
15 minutes. This is great for smaller pieces, like the
wheel wells, but more of a problem with larger panels.
I wanted to keep the body panels as large as possible to
maximize strength and minimize the number of joints to fill
and fair. I had hoped that by steaming the panel over
the wash tub, I could get the desired effect. Wrong!
With an air temperature in the mid 30°s the wood
cooled far too fast. I ended up bringing out all my
shop rags and soaking them in the near boiling water, placing
the soaking, steaming rags on the wood where I needed it to
bend, then working with clamps to persuade it some. It
worked, but it wasn't as easy as it should have been; one
quarter panel took me all afternoon to fenagle into place and
secure. If I ever do this again, I'll buy a horse
trough.
After having a terrible time getting the rear
quarter panel installed, I sawed the front quarter panel into
smaller pieces -- strips where the curves are trickiest --
and installed them with many, many little screws instead of
clamps. Clamps would get in the way of installing the
rest of the strips. The 130 screws will be removed
once the glue sets up hard. Then the screw holes and
seams between panels will be filled with automotive body
putty, faired off, and the whole thing sanded smooth ready to
paint.
With the body sanded smooth and a base coat
of gloss white on, Elf #2 is called in to lend her artistic
talents to the layout of the paint job. She also had
the foresight to bring along a die-cast model of the John
Force car to serve as a pattern... MUCH easier to visualize
this way than by working with the pictures I down loaded from
the internet. Especially since no two of these had the
same paint job!
Most of the paint is in place, and lettering is
going on. Now all that is needed is to produce many
many little sponsor stickers to give it that
'authentic' look. Also have to permanently
install the super-charger and it's air scoop, rear
spoiler, and of course the seat.
Of course everyone knows that dragsters
don't run knobby mud tires, which is what the original
truck came with, so it was necessary to turn them into racing
slicks. This was accomplished with black silicone
sealant and Styrofoam - used as a filler. As it turns
out, the wooden fender wells magnify and project the sound of
the electric motors into a satisfyingly powerful growl as the
car speeds around the family room.
The finished product was a tremendous hit with the
budding young racer and we are very happy to have been able
to make Charlie's Christmas so joyful.
Merry Christmas Charlie!
|