After learning lessons from building my first tricopter I was eager to build my second one, this one with a camera for HD recording and FPV views.
- Motors: Dt-750
- ESCs: Hobbyking 30, flashed with SimonK firmware
- Propellers: 11″, 1x CCW, 2x CW
- Battery: Zippy Compact 3s 4000mAH
- Flight controller: KK2
- Tail servo: Turnigy TGY-390DMH
- Receiver: FrSky V8FR-II
- FPV Camera: Sony Super HAD CCD 600TVL
- Video transmitter: generic 400mw 1.3GHz
- Nav lights: 3528 LED strips, type A (extra bright)
- Boom lights: WB2811B LED Strips
- Boom light controller: Arduino Nano, custom firmware
- Booms: custom made from solid red oak
- Frame, feet, yaw mechanism: custom fabricated from 3mm Baltic birch
- AUW (All Up Weight): 1446 grams (includes camera’s and battery)
All the parts were designed in AutoCAD and fabricated on my laser engraver. I went a little overboard with designing parts, but it was fun. I named this tricopter Sparkles, the name will make sense later.
In traditional tricopter fashion, the booms fold back for easy storage and transportation. The booms are held in the forward position by compression. The booms are made from red oak hard wood, nice and strong.
This tricopter’s purpose is a FPV (first person view) practice craft. The FPV camera is a Sony Super HAD CCD 600TVL. This camera was selected for it’s small size, fast refresh rate, high resolution, and excellent contrast response to ever changing lighting conditions.
The camera on the lower battery tray is a Mobius Action Cam. The Mobius is essentially a GoPro in a different package with little sacrifice in features and video quality. The Mobius also sits on the dashboard of my car as a dashcam when not attached to my tricopter.
The FPV camera can tilt’s from facing forward to almost fully in the down position. The tilt is controlled via a potentiometer on the transmitter. As you can see the camera is mounted in a custom fabricated box. The metal frame the camera was originally mounted in was rather heavy, too heavy.
The video is transmitted by a 1.3GHz 300mW transmitter. 1.3GHz was selected because it has greater range and less breakup over 5.8GHz systems. The transmitter cost only $35 and works great.
To the right of the transmitter is a relay and push button below the relay. When the button actuates the relay which switches power on to the transmitter. I added this feature because if the transmitter is turned on without an antenna attached the transmitter will be destroyed. (In the case the battery is connected to the tricopter and I forgot to attach the antenna) A little extra wiring an $1 relay has already saved me $35!
The purpose of this mounting system for the Mobius Action Cam is for vibration dampening. This technique was first implemented by David at rcexplorer.se (the inspiration behind my tricopter designs) My version uses extra large zip ties and they work great! Day and night difference in video quality over the camera being directly mounted to the frame vs mounted with antivibration.
The flight controller is the KK2 board and was selected for simplicity. The only feature the KK2 lacks over other flight controllers is altitude hold.
The receiver and transmitter set is from FrSky and is the V8FR-II. The custom mounting bracket keeps the grey antenna roughly at 90 degrees apart per receiver specification.
The landing gear/feet are simple and to the point. My last design the feet were attached via zip ties, and I broke those ties off every other landing. This time the feet being screwed in seems to be a better design as they tend only to break on sheared landings.
On of my favorite parts of the tricopter design is the yaw mechanism. The servo is a Turnigy TGY-390DMH; a bit expensive, but is high quality and the gears will not strip out in the event of a crash.
Also, you can see that that the motor is mounted by zip ties. On the event of a crash, the motors tend to pop the zip ties verses destroying the prop, motor shaft, or mounting brackets. A few pennies vs dollars of repairs.
The yaw mechanism has a full 180 degree rotation. Some flight controllers turn the yaw server mechanism a full 90 degrees from zero during arming, APM does this. The yaw mechanism is study, especially with the reinforcing strips glued onto the riser tabs.
The navigation lights are LED strips glued to circular mounting brackets. My first tricopter’s nav lights had an issue of being covered when the craft is at certain angles and causes disorientation. This mounting technique allows the nav lights to be visible at all angles.
The nav lights are manually activated via a toggle switch.
But wait, there’s more. UFO lights! Under the booms are strips of WS2811B LED strips.
Inside this box is an Arduino Nano that control the three WS2811B LED strips. The pattern is selected on the transmitter using one of the potentiometers.
More on the lights a little later when I take a good video of the system.
Here you can see the LED strips on the underside of the booms.
That’s it for now. Hopefully next summer I can take in flight videos of the awesome lighting system!