Recently I got my full scale pilot license and I started collaborating with a local enterprise taking aerial videos with an array of different machines.
I was blown away by the stability of the video that well tuned and GPS assisted multirotors can produce, so I decided to buy a cheap quad for myself to shoot videos in the spare time. Until today I have been using my loyal tricopter, which left a lot to be desired in terms of stability and accuracy.
Banggood was having a nice sale on their CX-20, so I pulled the trigger and got one. This is exactly the same model sold by Hobbyking under the name of Quanum Nova, and it is a great entry level AP platform.
Note:
The CX-20 by Banggood is sold in three versions: Open Source, Big Shark and Zero, while the Nova by Hobbyking apparently is always the Open source version. Needless to say...get the Open Source if you want the possibility to play with the APM based firmware and have access to future updates.
As usual, there is not a chance that a model of mine arrives to the maiden without some modding, and the CX-20 was not an exception:
- First of all I added a brushless 3 axis Gimbal for a Gopro. I am using the widely known GLB 3 axis gimbal with a Storm32 controller. More on that will follow on a separate article
- Upgraded propellers to cope with the added weight - use ORIGINAL DJI 9450s
- Added FPV capability to be able to frame the shots (Boscam TS351 VTx and Eachine 5802S diversity FPV screen)
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| The trusty Boscam TS351 I use on almost every FPV model I own, routed through the shell to expose the antenna |
- Added MinimOSD (which for the moment does not work though :) but more will follow on this
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| The Minim OSD installed in series between the gopro and the VTX |
- Moved the GPS antenna in the dome and shielded it with aluminium tape (like space B-movies of the 50's) to improve GPS reception and loiter accuracy. It works!!
My experience so far with this quadcopter, to be honest, is mixed: so far it flies horribly and it takes quite a lot of learning to program it properly.
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| I am using 3000mAh batteries, which do not fit inside the CX-20, so I had to get "creative" with fixing it... |
If you bought the Open Source CX-20 or the Quanum Nova you can plug it to your PC, fire up a software called "Mission Planner" (download it here) and calibrate the compass, the GPS, the radio, and tweak an impressive list of parameters to make your quad fly better (or worse).
Mission Planner is very intuitive to use, but make sure you read what is generally called "the Bible" of the APM copter system, found HERE.
Sooner than you think you will be able to program routes, waypoints, flight modes, and many more cool nerdy things to your quad, to have it fly autonomous missions.
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| Mission Planner screenshot showing waypoints. Image courtesy of APM |
Would I recommend this quad to everyone? Heck no! You can think of it as an android phone compared to an iphone (where the iphone is a DJI Phantom). If you enjoy tinkering, modding, saving some money, be able to expand the possibilities of your quad, by all means, get the CX-20 /Nova, you will not be disappointed. If you have the spare cash, and want a complete product (gimbal and camera are included) that works out of the box, at the price of using a closed system which you cannot modify or customise, the Phantom 3 is your choice.
There is a thread on RCGroups.com discussing this quadcopter. The thread is enormous and almost every topic has been discussed there...
It might take me a while to get this model tuned in, in the meantime...happy landings!
