They used a roboteq brushed DC motor controller with
simple analog inputs for position reference. The code they
wrote includes potentiometers and momentary switches in
The rest of the car is built ground-up, too. Among the
components Parsons worked with are the TREMEC T56
Magnum transmission, Wilwood disc brakes on Konig
wheels, GT Radial tires, and a Vortech supercharger.
In 2016, he used Solidworks to model and order
prototypes for a new version of the clutch system.
“I’ve been using Solidworks for quite some time before
this,” he says. “It just made sense to use Solidworks to
visualize everything when I made it, with respect to 3D
printing, the functions of how it would actually work and
looking at the model. Before I actually have it in my hands, I
can model it all and then order the parts, instead of ordering
the parts and then modeling, which saves time. I was
Solidworks-certified before the accident, so that helped out
Making the clutch required relatively little prototyping but a
lot of changes once he got it in the car.
The roll cage was another element he built mostly on his
own, using Solidworks CAD to scan the interior of the car. It
wasn’t easy for him to climb in and out of the body, and 3D
scanning the interior was much easier. He could tweak the
design in the data file instead of having to physically build
elements to test.
“Due to my issue that I’ve always had creating that stuff,
I’ve been lucky enough to have a 3D scanner at our shop.
We’ve been able to capture a lot of data from a lot of cars
relatively quickly. So I don’t have to do the testing, but I have
the data and can make changes whenever I want instead of
having to build a roll cage and iterate on it.”
One thing he doesn’t want to do is to make “half-assed
bars that get placed into cars for no reason.”
Before producing anything, he will adjust the elements for
strength, weight, and the location of the bars in order to find
what he wants. And part of that effort is aesthetic; it has to
look like a racer.
“We can play around with stuff that looks cool but
functions really cool too,” Parsons says.
At his shop he offers customization services like this.
“To do custom work, I have to acquire the car, scan it,
strip the interior, and then we can go into the 3D design. We
need to be able to CNC model and CNC bend it,” Parsons
The shop has grown a lot in the past year, and Parsons
says it’s stressful to manage the shop as a business and
learn more skills to apply to his own cars at the same time,
especially because money is always an issue. But he’s been
working on cars since he was 18, and some challenges in
his business don’t seem to be stopping him.
“Cars drove me into fabrication,” he says. “Actually, cars
shaped me into what I am today. If I didn’t play with a race
car, I wouldn’t do anything I do today. Cars were the things
that broke my back, but cars also saved my life. They helped
me recover after something so tragic.”
More information about the Chairslayer racer, its mission,
and the organization that supports it can be found at:
Like many of the parts for Chairslayer’s adaptive controls,
A close-up of the hand-operated potentiometer that feeds the driver’s
inputs into the Chairslayer’s digitally controlled clutch system.