The new camera gimbal

The Cave quad is designed as a payload carrier, strength, reliability and durability trump weight and performance.

The old camera gimbal was a cheap hobyking thing, and while it worked, it was never straightforward, and it didn't take a big impact to break it or make it fall apart. It also suffered from a limited range of motion in both directions.

The new one is direct drive, using much larger servos. The yaw servo has been modified to be continuous drive, so we should be able to look around 360 degrees, and the device is designed to be self contained, so it can rotate continuously in one direction for as long as desired.

The parts:

• Yaw servo (modified for continuous drive)
• Tilt servo
• Receiver
• Flip 32 flight controller
• Video Camera (Mobius Action Cam clone)
• Video transmitter
• OSD for Video
• 350mAh 3S battery
• 4 LED spotlights
• 2 voltage regulators

Using the FC to pass through the servos also has the advantage that the gimbal will be self stabilising to some degree, although the use, and effectiveness of that remains to be seen. 

Big Quad

This quad is a payload carrier, designed purely to fold up small, and lift a potentially heavy load.

It runs on a folding 60cm X platform with 10mm square cross section aluminum arms - it's a cheap and versatile platform from hobbyking, and spares are available.

This is lifted by 12 or 14" props, spun on 750kV motors.

The whole thing packs down into a length of 8" ID PVC plumbing pipe, making a waterpfoof and almost indestructible case that can fit throw confined spaces and be abused without damaging the quad itself.

A 5Ah 3S battery powers the motors and flight controller, with seperate small batteries for lights, cameras and 2 penlight lasers that assist in range-finding.




At the moment it runs twin recievers and video transmitters - one controlling the craft, and another controlling a gimball camera with live video transmission

The idea is to have modular plates that can be attatched or removed to alter the functionality, these will include:

• A secondary video layer
• Additional lighting for night work
• Additional sensors
• A parachute
• Bumpers and landing gear as required

Cave Quad - Finally we can record data

Finally we have the data logger functioning, apparently the original flight controller I was testing on is buggy on the UART 1 lines.

Solder the OpenLog datalogger direct to the flight controller, or via wires if that suits your layout better.

The settings required in Cleanflight are as follows:
 - Enable Blackbox on UART 1, set baudrate
 - Enable blackbox

Data is recorded whenever the craft is armed, and you can verify that it is recording by the flashing LED.

The data that is sent from Cleanflight is in binary format, and is not immediately human readable. The Cleanflight blackbox flight recorder viewer allows you to get a visualisation of some of the data, but it seems to be limited in what it can display.

Instead we are just converting the file into a .csv viewable in excel, as the main thing that we are interested in is the barometer value at the peak of the flight. This is accomplished using Blackbox Tools, and dragging and dropping complete and non-corrupted files onto the blacbox_decode.exe executable. This will give a csv file that includes all of the data embedded in the blackbox log, which includes barometer altitude as well as stick positions, motors etc.