Scratch-Building Multirotors

Written by Lucas Weakley Scratch Building Multirotors As seen in the Summer 2017 issue of Park Pilot.

I’ll be the first to admit that the way in which I acquire multirotors is not the most popular approach. When I want a new drone, I start from scratch, design a frame, have it CNC cut or 3-D printed, and source all of the hardware and electronics to make it fly as fast, as long, and as stable as I need. When I first started doing this in late 2010, I had no idea what I was doing. My first tricopter barely got off the ground because I chose underpowered motors. But even then, it was unthinkable to me to need to purchase a kit of parts to build a multirotor. Throughout the years, I have learned a ton and I now can design multirotors that rival many off-the-shelf units. But is the approach of building these aircraft really necessary? I’d like to share some thoughts about building vs. buying a multirotor.

Lucas’ second tricopter was more successful and flew better than his first, although his flying skills had not caught up yet, as you can probably tell from the look on his face! Photo by Kent Weakley.

Although I usually define building a multirotor as starting from scratch with designing and constructing a frame, purchasing a prefabricated frame still demands a lot of work before the aircraft is ready to fly. Motors, ESCs, batteries, controller boards, lights, etc. all have to be purchased to meet the requirements of the person flying the multirotor. The kit manufacturer might recommend an electronics parts list, but it’s still up to the builder to assemble the various components into a homogeneous, functioning aircraft.

Lucas’ third tricopter design was the most successful and is the aircraft that was used to film most of the aerial videos from 2012 that you can watch on his YouTube channel. Weakley photo.

In this sense, designing the frame of a multirotor is just an added customizability that someone could choose to do. Building from a kit or from scratch both require a lot of knowledge, so the process isn’t accessible to everyone—especially those who are new to RC. Buying an RTF (ready-to-fly) multirotor, on the other hand, is getting easier. Many of the videography drones on the market today take out the learning curve of both the assembly (many require none) and the flying. Control systems in these multirotors are so advanced that many people need little to no practice to fly them. This ease of use is enticing to someone who wants to use the aircraft as a tool instead of purchasing it for the fun of flying an RC model. I think this is an important distinction. I have built several multirotors for videography work in the past, and I still use them today. But I have to admit that today’s off-the-shelf aircraft with video cameras surpass anything I could put together as a kit for the same application of being an aerial camera. I don’t, however, usually build beginner-friendly video-taking quadcopters. Although these are great at what they do, for someone with a background in piloting RC aircraft, the simplified controls feel incredibly limiting.

This quadcopter is what replaced all of Lucas’ other videography multirotors. It was very stable. With the electronics that he sourced, it could fly for approximately 20 minutes. Photo by Lucas Weakley.

I prefer flying a multirotor with the throttle stick controlling the speed of my motors—not the rate of climb of the aircraft. When I pitch, roll, or yaw my multirotor, I prefer it to move the amount I input into the sticks, not stop at predetermined angles. Although features such as auto-leveling and heading-hold are convenient, they undeniably limit the versatility of the aircraft. This is, of course, my preference. There will always be a market for tools that people can use without much experience.

This quadcopter was meant to replace Lucas’ other video multirotors, but the design focused on looks more than performance and was subsequently too heavy and frequently overheated. Weakley photo.

Similarly, I believe there will also always be a sustained market for individuals who want to design and build their own custom aircraft. Take the ever-growing sport of FPV drone racing, for instance. Although there are RTF racing drones sold by several companies, most pilots assemble their own multirotors. Many of these people do a substantial amount of work, researching the best components and experimenting with different controller board settings. This research has become easier with the flood of how-to-related content in forums and YouTube videos in recent years.

In Lucas’ high school engineering program, he helped organize a project to design and build quadcopters. This was the aircraft that he designed as an example. Weakley photo.

What’s the big deal though? Why do I find it important to keep a do-it-yourself attitude in this hobby? Well, it mostly comes down to the increased respect for the aircraft. I have found that people who have built their own multirotors are much more cautious and responsible when flying them. For me, at least, this is because I see my aircraft as more than a single price tag that I can replace. I also enjoy this philosophy because I am a maker and am excited about designing a unique aircraft that solves a problem or attains an aspiration that I have.

In the same high school engineering project, Lucas helped his team design and build this quadcopter for a competition. It took approximately two hours to build. Now that was a challenge! Weakley photo.

The next time you want a new multirotor, consider skipping the off-the-shelf solutions. Jump onto YouTube, or talk with someone who is knowledgeable within your local flying group. Develop a new skill in electric RC multirotor design—it can be an incredibly satisfying experience. I hope to see your creations in the sky!