How to build a Tcopter
When my friend told me about the tricopter he was building, I decided to embark on a similar journey. We based our designs on the rcexplorer build which proved to be an excellent starting point. We both found however that the frame was susceptible to vibration, enabled propellers in the vision of wide angle on board cameras and was prone to breaking easily during a crash. It was then that I decided to try some other designs which led me to the Tcopter.
Why a Tcopter?
When I redesigned the Tcopter I wanted make it more suitable for filming, my main reason for building one in the first place. I wanted:
- to remove the propellers from camera sight
- reduce vibrations that were transferred to the camera
- make the frame more crash resistant through shock absorption
- make the frame easier to repair
- balance the frame yet make it smoother during flight
- make it float in water
- make it easier to land and have more protected propellers when landing at an angle
The Tcopter I designed worked surprisingly well. I really couldn’t believe how easily it ticked all the boxes and as you can see, the resulting video even with unbalanced slightly damaged motors and unbalanced propellers turned out great. The frame turned out a fair bit heavier than the RCexplorer tricopter frame, however I found the resulting video was much smoother with far less balancing work.
Several of my friends have wanted instructions on how to build a similar version, so I have decided to put up a build log here. It is one of the most rewarding (and challenging) experiences I have ever had and I can’t quite explain the satisfaction of being able to capture stunning HD video from a home made device which beams back a birds eye view from above.
That being said, it is harder than it looks to put one together with the available online resources, especially for someone (like me) with zero RC experience. So hopefully I have pulled together all the ingredients for a successful Tcopter and your build will be smooth and enjoyable.
Ordering the Parts
First up, you must order some parts. Whilst this may seem like a trivial part of the project, I have found it the most frustrating. Below I will list the parts you need for your build, but you will find that only a handful are ever in stock. Since model builds and access to build logs like this are gaining popularity, parts for such builds are becoming increasingly more difficult to get hold of. That said, I will try and offer alternative choices which will get you flying asap. I have also listed the bare minimum requirement and also a guess at how many spares you will need to begin with. There is nothing worse than finally getting your Tcopter in the air only to find that a critical spare part is out of stock for a month.
Servo: BMS-385DMAX Digital Servo x 1
KK Board (stabalisation): HobbyKing Multi-Rotor Control Board V2.1 x 1
Transmitter Controller: Turnigy 9X 9Ch Transmitter w/ Module & 8ch Receiver (Mode 2) x 1
Battery Charger: Turnigy Accucel-6 50W 6A Balancer/Charger w/ accessories x 1
Connectors and Miscellaneous
Steering Mounts for mounting servo connection: Front Wheel Steering Arm & Mount Set 40mm x 1
Battery Connector: Nylon XT60 Connector x 1
Motor Connection: PolyMax 3.5mm Gold Connectors x 1
Male to Male Servo Lead: 10CM Male to Male Servo Lead (JR) 26AWG x 1
Wire: Red Turnigy Pure-Silicone Wire 16AWG x 4
Wire: Black Turnigy Pure-Silicone Wire 16AWG x 1
Heatshrink Tubing: Turnigy Heat Shrink Tube 25mm Transparent x 1
Building the Frame
The frame can be made out of locally purchased materials. It is really just a light, robust but flexible structure that allows your 3 motors to be spread in a Y or T shape with all the other bits mounted so that the balance point is where your control board is mounted.
For my latest design I used electrical conjuit as it is cheap, light, and fits neatly into common connectors ideal for building a frame out of. It is a bit heavier than carbon fibre, but this doesn’t concern me. It is easy to make, cheap, and any extra weight increases frame inertia which isn’t such a bad thing for reducing camera vibrations either.
First Person View (FPV) Flying
Once you have a flying tricopter or tcopter, a whole new (but slightly expensive) world awaits when you delve into the wonderful world of FPV. FPV view is essentially a video link from your Tcopter to you on the ground which allows you to see exactly what your Tcopter sees!
Here are the parts you will need for an FPV setup:
- A camera with a video output – eg. GoPro Hero 2
- A video transmitter and receiver
- a TV or video goggles which allow you to see the video output from your Tcopter
Camera for FPV
You can either use the video output from your onboard video recording camera such as a GoPro, or you can use an additional camera.
Video transmitter / Receiver
- Choose one which is in a different frequency range to that of your remote control.
- Choose one which does not interfere with military or other restricted frequency waves in your country
- Choose one which is suitable for the terrain you typically fly around. The lower frequency video transmitters will be less effected by trees and things interupting line of sight between your transmitter and receiver.
Goggles or TV screen
If you can afford it, buy a set of goggles, they win hands down every time, don’t need mains power in the field, block out daylight, and even allow head tilt features which you may consider installing down the track.
If you want to start out cheaply, an existing TV provided it is rigged up to your receiver which is placed outdoors can work just fine. Just note that you should avoid flying over cars/buildings/people/infrastructure especially when starting out as a crash could do some serious damage or injure someone. For this reason, I have dived in and spent my money on some goggles and not regretted it one bit. I can go into the most stunning remote natural landscapes, pop my goggles on and start flying. They can be powered off a standard battery pack and draw very little power.
Setting up the Tcopter
Once you have built the Tcopter, you will need to set up these things:
- flash the KK board with the correct firmware (RCexplorer has an excellent walkthought here)
- calibrate the speed controllers
- change remote from type 2 to type 1
- set up directions on remote control
- set exponentials on remote control
- set centre points on remote control
- calibrate level sensors for stability
I will try and gradually add information for all the above.