RC Helicopter - 2012/05
Using a helicopter for photography
by Mark Fadely [email protected]
Hi, everyone. Thanks for visiting the “RC Helicopter” column this month. I have an interesting interview with an active Unmanned Aerial Vehicle (UAV) pilot located in the Midwest. UAVs have recently been a hot topic and it is fun to hear from a photo-based UAV operator. Here is what I learned from this passionate RC helicopter pilot.
MF: Thanks for talking with me. Could you tell us a little bit about yourself? SB: My name is Stephen Born and I live in Springfield, Illinois. I am 35 years old and have been flying RC helicopters for six years. I have been the secretary of our flying club for two years.
MF: What kind of UAV photography/video equipment do you use? SB: The helicopter I chose for my camera aircraft is an electric Align T-Rex 800. I decided to go with the flybarless system. A lot of aerial photographers use a flybar because it works with the entire rotor system. This makes the helicopter more stable than the flybarless system, which uses three gyros for cyclic correction. Stabilization response is generally faster with a flybar system. The gyros in a flybarless system will respond and correct movements after the helicopter has already shifted. The downside of using a flybar is the drag from the paddles and the occasional boom strikes.
My front-mount tube system is the PhotoShip One 2XPT — a two-axis camera mount system for RC helicopters. I chose the 2XPT because it was designed for use on 600- to 800-class helicopters. Due to inherent vibrations with RC helicopters, vibration reduction is at the forefront of a camera gimbal’s design. Vibration isolation is handled by LORD vibration isolators and silicone oil dampers arranged in a specific geometry.
There are two different styles of camera mounts: the front mount and the underslung mount. Underslung systems can create negative issues such as the pendulum effect and are difficult to autorotate. The PhotoShip One 2XPT is a front-mount system, as opposed to an underslung one.
MF: What do you know about the history of UAV development? SB: Any aircraft system without a flight crew has been termed a UAV. There are two forms of UAVs: ones that are remote-controlled and ones that are preprogrammed and autonomous. Most early UAV aircraft were not autonomous at all. More advanced setups, such as built-in guidance systems and sophisticated navigation, have since been developed. The National Model Aircraft Safety Code and AMA guidelines have a complete list of rules to follow when flying models as UAVs. These include, but are not limited to, aircraft weight, altitude limits, and keeping a direct line of sight on your aircraft.
MF: What safety concerns need to be addressed when flying UAVs? SB: Safety plays a large role when flying a UAV. With 700- to 800-class helicopters, each main rotor blade can be 800 mm long, moving at 1,350 rpm. Make sure the camera and camera mount are secure — you do not want your camera to become detached from the mount while hovering. Another risk is flying over highly populated areas.
MF: How did you get started taking pictures with your helicopters? SB: I started flying 450-class helicopters about six years ago. I went into our local hobby shop for heli parts and noticed a GoPro camera on display. I bought the camera and mounted it to my 450 heli. I went to our local flying field and took pictures of the pilots flying their airplanes and helicopters. I have always had a passion for photography and appreciate the techniques involved for that perfect shot. So I decided to combine both passions into one. Taking pictures with my helicopter has become a great hobby for me.
MF: Do you have concerns with people flying first-person view (FPV) vehicles? SB: As a member of the AMA, I am familiar with the National Model Aircraft Safety Code. An FPV-equipped model must be flown by two AMA members using a buddy-box system. The pilot in command must be on the primary transmitter, maintain visual contact, and be prepared to assume control in the event of a problem.
Accordingly, I do not fly FPV because I would not be in direct visual contact with my heli. I fly the helicopter with no visual obstructions while my cameraman manipulates the camera gimbal. I would like to make it clear that I have never flown FPV.
MF: Did you have video/photography experience or knowledge before starting the UAV project? SB: I had no prior experience with video or photography. I have learned through experience that a great picture will paint a story and good composition is the key to taking great photos.
The most desirable time to take pictures is in the first or last hour of the day. Structures in photos taken during these hours will show heightened shapes due to the shadows produced by the sun's angle.
MF: Have you had any accidents or incidents? SB: I have never had an accident or incident. I am all about safety. If I plan to fly tomorrow, I will do a preflight check the day before. I have found that by doing this I am not rushing my mandatory maintenance routine.
With so many moving parts, bearings, and electronics, there are many things that can go wrong. Having an issue when your heli is 75 feet in the air can get complicated. Preparing for the worst, I have a chosen location for an emergency autorotation before the main rotors turn.
MF: Do helicopters make better platforms for UAVs than airplanes? SB: With all the options available these days, it can get quite confusing. Larger helicopters are easier to see when far away, give you more stability while flying, and handle wind conditions a lot better than a smaller heli.
In my experience, the 90-size or 600- to 800-class helicopters are perfect for aerial photography. You should build your helicopter, electronics, and equipment around your camera. The main reason is you have to lift the camera and equipment off the ground.
MF: What do you think about all of the multi-propeller/rotor helicopters appearing on the market now? What type of aircraft would make the perfect UAV? SB: Multirotor systems are more stable than a single-rotor system. In a multirotor system, you may be using three to six rotor discs. When there are that many rotors, there are that many potential problems. If a motor were to cut out on a multirotor, the unit would become unstable and could potentially tip over. With a single-rotor system, you are using one disc. On a helicopter, if the motor cuts out, you would be able to complete an autorotation.
MF: Tell us about the advancements in GPS, autopilot, and other electronic systems. SB: Companies are making GPS and autopilot installation simple for a wide number of UAV platforms. Digital servos and computer modules are much smaller and lighter than they were in the past. In addition, vertical sensors allow for automatic and continuous in-flight weather calibration.
Another added benefit is telemetry, which allows data from your RC aircraft to link back to your radio. The information received on your transmitter can include temperatures from your ESC, motor, battery, and your receiver voltage.
MF: Do you have any advice for pilots who would like to give UAVs a try? SB: There are many things to consider. The most important one is the camera and the type of mount you want to use. You need to figure the weight of the camera and gimbal mount. This will give you an idea of what electronics, head speed, gear ratio, and pinion you will need. After that, build around the camera.
To get started taking pictures, a 450- to 500-class heli rudimentary setup will be fine. If you have the passion, enthusiasm, and devotion to really make fine videos and photos, you will need to invest in a larger-class helicopter. The cost of a 450-size heli crash will typically run $30 to $40 for repairs. Your main blades on a 700-class helicopter cost $200 or more. In this hobby, I have found you get what you pay for.
Thanks, Stephen. Hearing about your experiences in the hobby gives us better insight into what is happening within the UAV aerial photography world. We all appreciate you sharing and being so open about the way you do things.
Good luck, and I hope to see you at an event soon.
Sources
- AerialSkyCam — [email protected] — www.aerialskycam.com
- International Radio Controlled Helicopter Association — www.ircha.org
Transcribed from original scans by AI. Minor OCR errors may remain.
