The Karl brothers—Ryley, Keegan and River—had a clear vision: They dreamed of a fast and efficient lightweight aircraft kit. The problem? Nothing existed that met their specifications, standards and wish list.
So they decided to start their own company to create kits for hobbyists to build planes in their own garages. The dream started in 2014, when the brothers formed DarkAero Inc. in Madison, Wis. Although they readily admit that the company was little more than a name on paper at that time as they all had full-time jobs, leaving them with limited spare time to devote to their passion.
This changed in 2017 when the siblings quit their corporate gigs and pooled their savings. Growing up in Frederic, Wis., the brothers were always building something, tinkering with it and/or taking it apart to see how it worked. They each bring a specific area of expertise to the group, specializing in different engineering disciplines with degrees from the University of Wisconsin-Madison. Ryley Karl, the eldest at 38, is an aerospace engineer; Keegan, 36, is a mechanical engineer; and River is an electrical engineer.
Getting Started
After taking flying lessons and building a plane from a rival kit, the brothers did a lot of research, rented hanger space and purchased some shop equipment.
But they knew it wouldn’t be easy getting the business off the ground, let alone sustaining success. According to the U.S. Bureau of Labor Statistics, about half of new businesses fail within the first five years and only 25% make it to 15 years.
Starting a company that makes so-called experimental kit airplanes has even more challenges than most businesses, including safety and regulatory concerns. But the Karl brothers were determined to succeed, and now are on the verge of launching the DarkAero 1 personal aircraft—with the help of industry partners such as CNC provider Tormach Inc.
The standard kit will include all the airframe components—the airframe itself, canopy, engine mount, landing gear, control hardware, fittings and fasteners, and, of course, detailed instructions. Other components, such as the engine, avionics, wheels and brakes, propeller and paint, will need to be purchased separately. The emphasis is on lightweight components that are ready for assembly, without overly complex requirements.
The complete flying cost of a DarkAero 1 is estimated at about $200,000.
The two-seater is expected to have a cruising speed of 275 mph and a 1,700-mile range. Designed around a 200-hp UL Power engine, the DarkAero 1 has a 750-lb useful payload.
Machining Partners
“What we’re doing at DarkAero is developing a high-performance aircraft kit that combines lightweight composite materials with precision-engineered metal components,” says Keegan Karl, co-founder and vice president of DarkAero. “We’re now transitioning from the prototyping stage into flight testing and production activities. Throughout the whole process, we have been using Tormach equipment, including the 1100 PCNC and now, our newest model, the 1500MX.”
The Madison, Wisc.-based, 11-person operation expects to grow with demand as well.
But as a self-funded startup set on vertical integration, they needed more information regarding specific materials that would be lightweight enough and still have the necessary strength. Along with their research, they understood there would have to be a lot of novel design, prototyping and testing. And they knew all of this would not be easy on a start-up budget.
“Someone has to have solved some of these problems before, and some of that information has to be out there already,” Keegan Karl recalls. So after countless Google searches and YouTube videos, he found resources such as NYC CNC, Titans of CNC and Saunders Machining Works. But the complications of prototyping testable parts remained, along with the incredible expense and time required to outsource production. Once again, the Karls took to the Internet and, this time, discovered Tormach, a manufacturer of CNC milling machines, “practically right in our own backyard” Keegan says, noting that the equipment manufacturer is also based in Madison.
Small-Scale Precision
Especially in aerospace development and manufacturing, there are plenty of opportunities for things to get out of hand and become overly complex. Prototyping in-house with Tormach machines allows DarkAero the ability to avoid many possible pitfalls, which is precisely Tormach’s mission.
When it started in 2001, Tormach says no company was producing CNC machines that were highly capable in a smaller size. Options were limited at that time to small or good, but you couldn’t have both, the company claims. Tormach set out to fill this gap, not with a “one-size-fits-all tool that was right for everyone, but (with something that) for some, could make a huge impact,” the company says.
Tormach now boasts a long list of notable customers, including NASA, the U.S. Navy, Oak Ridge National Laboratory and Tesla.
The Need for Speed
The ability to rapidly produce high-quality production-ready aerospace parts without having to go through layers of suppliers before being able to test a part allows DarkAero to mitigate risk and transition beyond prototyping more efficiently, according to DarkAero.
While the brothers were happy with the Tormach 1100, the new 1500MX was able to get the job done faster with a higher material removal rate. It also provides smoother finishes, which can make a big difference when testing aircraft prototype components.
In a video posted on the company’s website detailing some of the capabilities of the Tormach 1500MX, Keegan points out that DarkAero owns the first production unit of the Tormach 1500MX. A servo-driven CNC mill with linear rails and an epoxy granite frame, the 1500MX features:
a spindle capable of going up to 10,000 rpm;rapid movements for the X and Y capable of 12,000 inches per minute; and600 inches per minute in the Z.
This allows for a much greater material removal rate than with the previous machine, which provides the additional advantage of making it better suited for production, according to DarkAero. There is also through-spindle coolant capability and a touchscreen that is described as “nice and really intuitive to use,” and a washdown feature allows for easy chip cleanup to save time and labor, the company adds. Additionally, there is a built-in camera that records any emergency stop events to quickly diagnose problems.
An automatic tool changer saves time, Keegan says. “You can upload your program, hit go and then walk away to get other things done without worrying about chip evacuation or changing out tools.”
Following an in-person demonstration, the Karl brothers could see how the 1500MX’s capabilities to produce larger components would suit their needs. The North American-made 1500MX allows DarkAero to create its own prototype components. And Tormach’s servo motors with 23-bit absolute encoders and battery backup also meant DarkAero never had to reference the machine, even between power cycles, making the system that much more attractive.
“I could essentially just put the G-code into the machine and let it go,” Keegan recalls. “Plus, with its ease of use, there will be a much shorter training curve for new employees as the organization grows.”
Taking Flight
The Tormach 1500MX has improved workflow, especially regarding production readiness and precision. As a result, DarkAero expects to launch the standard production kit available within a year. “We are looking at a slow ramp up, probably only producing a handful of kits in the first year. But within a few years we are targeting 50-plus kits annually,” River says.
“We were able to make much of what we needed on the Tormach 1100, pushing it pretty far,” he continues. “ But the main thing we were looking for was doing things faster and being able to work on materials like steel. And to work on those materials more quickly.”
Not only does the Tormach 1500MX provide the benefit of not having to spend extensive capital outsourcing one-off components for proof-of-concept, but DarkAero also successfully shortened its feedback loop for making improvements to designs.
“We owe a lot of the successes that have gotten us where we are today to companies like Tormach, who make such equipment accessible to startups,” Keegan Karl says. “With our own Tormach 1500MX, we are able to get much more quickly and efficiently to better designs for manufacturing.”
For more information about DarkAero, visit www.darkaero.com or call 608-616-9409. For more information about Tormach, visit tormach.com or call 608-849-8381.
