In my last article, I explained how I used a mini-quadcopter as the basis for a DIY hovercraft. My inspiration for that project was the Tiny Whoov, a hovercraft built around the Blade Inductrix. Blade sells their own hovercraft adaptation, called the Inductrix Switch. Just recently, Blade released yet another new vehicle based on the Inductrix frame, the Inductrix Switch Air.
The Inductrix Switch Air introduces a set of wings to the quadcopter frame. A few simple transformation steps allow you to fly this machine as a pure quad or as an airplane/quad hybrid. Furthermore, the quadcopter components can be snapped into the hovercraft hull of the Switch. This makes the Inductrix Switch Air a sort of 3-in-1 flying machine.
About the Inductrix Switch Air
First things first: "Inductrix Switch Air" is a mouthful. So I'll just call it the "Air" in this article. Blade offers the Air in two variants. The Ready-to-Fly (RTF) model ($60) includes everything needed to get this machine in the sky. If you already own a compatible Spektrum transmitter, you can save a ten bucks by going with the Bind-N-Fly (BNF) version ($50).
I have the RTF model. The included 2.4GHz transmitter is considerably smaller than a standard RC transmitter, but it is still large enough for my adult hands to hold and use comfortably. The package also includes four AA-size alkaline batteries to power the radio.
There are features within the transmitter that belie its outward minimalist appearance. The quad's onboard flight controller (FC) has separate flight modes for each form of the vehicle (quad/wing/hovercraft). These modes define how the vehicle responds to control inputs. They are selected by moving the control sticks to specific positions before arming the motors. A multi-colored LED on the FC indicates which mode is selected. Additional options within each flight mode are chosen by pressing inward (axially) on the right control stick. An inward push on the left control stick toggles motor arming.
The quad is powered by a 150mAh single-cell LiPo battery. Flight/drive times are typically less than 5 minutes. So, you'll want to grab a few spare batteries ($4). Blade includes a USB-powered charger. It takes about 30 minutes to charge a dead LiPo. It works fine and is convenient, but I prefer the more detailed charging oversight provided by my fancier chargers.
A clever modular design is the key to this quad's shape-shifting traits. A core central unit contains the flight controller board and battery mount. Each of the four shrouded fan units simply snaps into place. Gentle pressure with a fingernail is adequate to mate or demate a fan with the frame.
There are two sub-mode options within the quadcopter flight mode: Stability and Agility. Stability mode is essentially what is commonly called Horizon mode. There are limits to how far the quad can pitch and roll. The amount you deflect the right control stick defines how far the quad tilts or rolls. Releasing the right stick causes the quad to self-level.
Most rookie pilots find Stability/Horizon mode the easiest to fly with. Even so, the Inductrix is very nimble with this setting. I was able to zoom around my living room at impressive speeds with complete control.
Agility mode is equivalent to rate mode in other quads. The amount you move the right control stick defines how quickly the quad pitches and rolls. There are no limits, so the quad can be flipped and rolled with skilled hands. Agility mode does not provide self-leveling.
While Agility mode is more challenging to fly, it also offers the most control. You will definitely be a better pilot once you get used to the nuances of flying in Agility mode. The tough, lightweight Inductrix is a good learning platform.
Overall, the Inductrix Switch Air in pure quad form is a fun little machine. It is quite maneuverable and relatively fast. There's a good reason that they are so popular for organized indoor drone racing. I've found that the shrouded props come in handy when you bump into something (and you will bump into things!). The quad will often bounce off and keep flying!
Flying Wing Operation
The wing components consist of a 1-piece foam wing and a plastic bracket for attaching the rear rotors. I tacked the bracket to the wing with a few small drops of Foam-Tac so that it would not fall off and get lost when the quad is unattached. Small tabs of Velcro help hold the front fans in place.
Within the Air flight mode are two sub-modes: Beginner and Expert. The only difference is that Beginner mode mixes roll and yaw commands into right/left movements of the right control stick. Expert keeps these commands separate, with yaw control on the left stick.
Flying with the wing in place is a unique experience. There are no aerodynamic control surfaces on the Air. All control is accomplished via differential thrust and torque of the four rotors. It's not much like flying a regular fixed-wing model. Nor is it quite like flying a pure quad. Although it is definitely more quad-like than wing-like. Despite the nuances, I think the Air is easy to fly. I had no trouble adapting and got used to the controls quickly.
Takeoff (and landing) is done vertically. The Air auto-levels in a slight nose-high attitude. Once airborne, you push the right stick forward to pitch the nose down and get the Air moving forward with the wing basically horizontal.
In slow forward flight, the wing doesn't generate enough lift to be of any significant help to the fans. But that doesn't mean that it isn't beneficial. When flying the Air within my home office, I thought it was exceptionally easy to control. I attribute this to two things. First of all, control response is more sedate than in pure quad form. I don't know if this is a result of different factory control settings or physical effects of the mass and area of the wing. Whatever, the cause, the controls are noticeably softened. The other obvious change is that the wing provides excellent visual orientation…which is always a challenge when flying multi-rotors via line-of sight. I feel comfortable flying the Air much further away from me and more aggressively than I do when it is in quadrotor form.
Whatever work the wing may be doing, it certainly provides a dramatic visual effect. It looks like an airplane flying very slowly…and that's fun. I have a few fixed-wing models that I can fly within my house, but none are as stress-free and maneuverable as the Air. It will even fly backwards!
I have a few fixed-wing models that I can fly within my house, but none are as stress-free and maneuverable as the Air.
The faster you fly the Air, the more airplane-like it behaves. You really need an indoor basketball court or similar space to fully explore the Air's performance envelope. I've flown the Air in a large indoor space as well as outside (on a very calm day).
I'm impressed by how fast the Air moves at full-gallop. I'm not sure if it's faster as a quad or wing. Any top-speed time in quad form is limited to very short sprints to keep it close enough to see. The enhanced visual cues with the wing attached allow me maintain full speed indefinitely within a very comfortable area. Ignoring any actual data that may exist, it just feels faster to me with the wing.
Blade claims that as you build forward speed and the wing begins to generate lift, the forward fans slow down to produce less lift. It makes sense, but I have not figured out a way to test how much of a shift actually takes place. The data junkie in me thinks it would be interesting to analyze what's going on.
Yaw control is very effective with the Air. It turns nicely whether flying fast or slow. Roll control is much less a factor. I'm not even sure it's necessary. Aerobatics are not on the menu. The fun with flying the Air is weaving around barstools and basketball hoops in areas where most other fixed-wing models dare not fly.
Hovercraft parts are not included with either version of the Air, but the RTF transmitter is preprogrammed with hovercraft flight modes. You'll need to purchase a Skirt $10, Base Plate ($8), and Screws ($4) to assemble a complete hovercraft hull to mate with the Air's quad core Likewise, hobbyists who have the Inductrix Switch hovercraft, can upgrade their model with wing flight modes.
The hovercraft sub-modes are Single-Stick and Dual-Stick. Dual-Stick provides discrete control of the lift (front) fans and the propulsion (rear) fans with up/down movements of the right and left control sticks, respectively. Directional control is via left/right movement of the left stick. Single-Stick mode puts all control on the right stick. Lift and propulsion controls are combined in up/down movement, while yaw is commanded with left/right movement.
I prefer using Single-Stick mode most of the time. Dual-Stick may offer more precise control, but it seems like overkill to me. I have no trouble driving the hovercraft exactly the way I want using only the Single-Stick option.
The Switch hovercraft works best on smooth floors, but it will also scoot across rugs. It is significantly smaller than my DIY hovercraft, and that makes it easier to drive around in tight spaces. Want to rip a top-speed dash through the kitchen? No problem…send it!
I am impressed by how maneuverable this little hovercraft can be. Combined with its small profile and footprint, you can set up a racing course just about anywhere. There's no need to worry if your racing gets out of hand. The foam shell of the hovercraft is like a giant bumper. I've smacked it into a wall at full speed and it just bounced off.
As with my DIY hovercraft, my only problem so far is related to dog hair. It seems particularly attracted to the propulsion fans of the Switch. I remove the props between every run to untangle the mass of hair that invariably gets wrapped around each motor shaft.
I'm writing this while in the thick of winter here in Buffalo. This is the time of year when I have an extra appreciation for indoor RC options. The Inductrix Switch Air offers three significantly different RC experiences with one core platform. I think it will be a good remedy for cabin fever until spring arrives...not that I plan to stop using it then!
Terry is a freelance writer living in Buffalo, NY. Visit his website at TerryDunn.org and follow him on Twitter and Facebook. You can also hear Terry talk about RC hobbies as one of the hosts of the RC Roundtable podcast.