All good things come to and end and so it is with the Son of FrankenSolo. What a fun project.
I built a gimbal for this project using OlliW’s STorM32NT gimbal controller. OlliW has provided excellent compatibility with Ardupilot and your choice of connection methods. You can use PWM, Sbus, Spektrum or serial connections between the flight controller and the gimbal. You can use Mavlink or OlliW’s own STorM32 mode serial. Lastly you can use native mode STorM32 as I did which is a serial connection and the Betacopter branch of Ardupilot which includes OlliW’s improvements for his gimbal. Native mode has the richest set of features.
I was unhappy with all the Nex sized gimbal frame kits I bought. Some the adjustments on the axis were not long enough to properly balance the camera. If you can’t balance the gimbal it is game over no reason to continue. Some I did not like the way the anti-vibration plate worked. In my opinion the rubber anti-vibration balls must be in compression. This means the yaw motor must attach to the top plate of the anti-vibration platform and not the bottom. It is critical to stop vibrations from the multirotor affecting the video. Next I want the cables to be dressed neatly and not floppy around in big loops. This means using hollow shaft motors and running your cables through the center of your motors. You can’t have gimbal balance if your cables change position as the gimbal moves around. As OlliW pointed out to me you can’t have the cables going through the motor jam up and cause the motor not to rotate freely, however. It seems appropriate for the Son of FrankenSolo project that I build a FrankenGimbal from all my gimbal kits acquired over the years. I was able to cherry pick the parts that worked for me and finally build a gimbal I was happy with.
So one of the most difficult aspects of building a gimbal is the management of cables. That is one advantage of OlliW’s NT gimbal system because in the distributed motor module version, which I did not use, the only wires going to each motor are the NT bus which is tx, rx power and ground with power to the motors for 5 wires.
The most difficult of the whole project is getting control of your camera. You need to get video from the camera up to transmit to the ground and you need whatever control you want to trigger or zoom etc your camera. This is a good reason to consider these factors before you decide on a camera.
The camera and gimbal is a major payload for the multirotor and never forget that every gram counts. A heavy gimbal and camera can instantly weight down your multirotor such that you end up with 5 minute flight time. Don’t forget that adding battery power to get more time is a lost cause. You end up adding battery just to lift the new battery you added with no change in your flight time.
It is a complete system and when you design a multirotor you need to consider the payload right from the start.
I am using a Ricoh GR because it produces high quality images and it is lighter than most camera in this size class at 245grams. The gimbal wound up weighing 505grams. The AUW weight is 4000grams with the 10500mah TItan LI-ION battery.
I love using the Solo motherboard for DIY projects. I have the Solo Controller running Solex on my Tablet with video from the Son of FrankenSolo displayed on the tablet. But for actual flight I will use my goggles. I just can’t see the tablet display in sunlight. Solex has voice commands which is nice. The only thing better would be OlliW’s new Pixhawk cube carrier board with the Sololink IMX6 board piggy back.
I like the lights on the quad. WIth OlliW oreo lights the status of the quad can be easily seen and my Flytron Neo light strips are a lifesaver for me. I have a real hard time determining direction of the aircraft in the air and the neo lights have a running white light that moves toward the front of the aircraft, pointing me to the forward direction, red lights on the right and green lights on the left rear of the aircraft help determine orientation.
Using OlliW’s UC4H via UAVCAN has been easy to build and easy to troubleshoot. It is a complete system now with a general purpose CANbus node, available off the shelf from JDrones, that can connect all your existing peripherals to your multirotor on a robust common bus.
Now the final step to see how it flies and determine the flight time.