Hobbyking i86 / Eagle N6 Multi-Rotor Control Board Review

June 7, 2012 22:34 | By | 10 Comments

At a mere $20, the Hobbyking i86 is a cheap clone of the Eagle N6 V1 board. Unlike KK, MultiWii and most other boards it does not require the user to flash a firmware in order to fly, instead the airframe type can be set via DIP switches. It’s simple, it’s cheap and it’s small, but is it worth saving money on the controller board?

The i86 / Eagle N6 controller is one of the most compact boards on the market

The first noticeable thing is the size of the board. It’s tiny, only 40x40mm, weighing just 8 grams! At that size it’s feasible to put this board into a small foamie plane as stabilizer. The board has a nice quality feel to it, the soldering is top notch and the multilayer PCB really feels solid. This is not a board that will break easily. Servo output is clocked at 400 Hz, which can pose a problem with low-speed ESCs, so make sure you get  an ESC that supports a high update rate. Turnigy Plush are usually a solid bet, but HobbyWing ESCs seem to work fine too. Supported input voltage ranges from 4V to 6V.

The i86 board installed in a 450-size quad frame

Much like the KK board, there are three pots for changing sensitivity (as well as some basic setup, which we’ll get to later) – a telltale sign that the i86 board is based solely on a gyro. The gyro sensor used here is an integrated STM 3-axis MEMS type, sitting smack in the middle of the PCB. Aside from connectors for up to 6 motors and the receiver inputs, you get a block of DIP switches for selecting the airframe type and flying mode, and an ISP socket for programming new firmware.  The good news is that there’s already alternative firmwares out there for the Eagle N6 and they work just fine on the i86 too. The even better news: You don’t need to care about getting an ISP board and upgrading the firmware. This controller just works.

Eagle recently released a Version 2 of their controller board, which features an external crystal oscillator for the microcontroller, but lacks support for fixed wing airplanes. In our opinion that’s a bad trade, as the crystal won’t do you much good in practice, while the airplane mode is an intriguing capability considering that most airplane gyros have worse gyro chips and cost more.

The i86 / Eagle N6 supports everything from airplanes to hexacopters and a few more exotic variations. Not bad for $20

Setup is quite simple, you start with a basic airplane program on your transmitter, and don’t change anything (except for the throttle reverse for Futaba owners, but they are used to that already…). Then you set the DIP switches to configure the right airframe type.

To configure the stick center position, just turn the PITCH potentiometer counter clockwise to zero, keep all transmitter sticks centered and the throttle at zero, connect the battery, and wait until the two LEDs stop flashing and only the blue LED stays lit. Then you disconnect the battery, rotate the pitch pot back to center position, and you’re ready to fly!

The only other available configuration mode is activated by dialing the ROLL pot to zero, which will make the board forward all throttle input directly to the ESCs. As you might have guessed, this is used for programming your ESCs for things like throttle range and such. We found that most ESCs work just fine with the defaults however.

This board comes with an arming mechanism that is tied to the elevator input. To arm the board, just move the elevator stick down and hold it there for two seconds, at which time the blue LED will light up. Check that the props are turning in the right directions, and then carefully apply throttle. During your first hover just check if the control directions are correct (we had to reverse rudder direction on our Futaba 12FG) and then you’re set! If the copter feels “mushy” and you have to work a lot to keep it in place, dial up the pitch and roll potentiometers on the controller board. Thankfully changing sensitivity can be done on the fly, no need to repower the controller. Changing airframe type and flight mode however DO require a powerdown.

Speaking of flight mode, the i86 supports a beginner and a “sport” mode. Beginner mode is the default, and will keep the quad much more stable and limit your control inputs to a safe range. This is good for filming and related activities, while sport mode gives you free reign and agile controls.

Flight Performance

Simplicity and cheap price count for no