You can build this frame in a day using a 3D printer and a few carbon fiber tubes, The frame is lightweight and was designed to carry a variety of companion computers and other sensors. Fully assembled the frame itself weighs less than 400 grams empty and can carry a lot of gear.
The various assemblies slide onto the carbon fiber tubes using 3D printed parts for each assembly. Relocating or adding new sensors is simple using the sliding rail systems. All of the rail parts are locked in place, except the battery tray which can slide back and forth and then lock to adjust CG.
In this build the drone is configured for Pixhawk and an Odroid XU4 computer, as well as a Raspberry Pi.
On board it has two thermal cameras facing forward and down, IR Lock Landing Sensor, Lightware SF10 Laser Altimeter, OpenMV sensor, and 3 RGB cameras. Below is the downward facing sensor package, including IR Lock generously donated by Thomas Stone.
The mission for this drone is to locate a human in the water using the thermal camera, then fly toward the person and deliver an automatically inflating life preserver. On a thermal camera the image of a person in the water is very distinct and clear. With both forward and down facing 320x240 thermal cameras, the companion computer can also assist in navigation.
This version has a Pixhawk Flight Controller mounted on it, connected to an Odroid XU4 Computer, and there is also a second Raspberry Pi 3 on board to drive the down facing 1080P RGB and Thermal Cameras.
The forward facing 4K RGB and Seek Compact Pro 320x240 cameras are connect to the Odroid SBC running Ubunu 16.06 and FlytOS to run the ROS Application for the camera.
Some of the parts are laminated with Carbon Fiber Cloth and Epoxy Resin for reinforcement. The carbon lamination does not add as much weight as you would think and adds enormous strength. The next version will have vaccuum bagged parts.
I have also fitted this frame with Qualcomm's Snapdragon Flight development board. Since Snapdragon Flight has on board WiFi, the other single board computers can send data and image streams via WiFi.
The parts can print on most any 3D printer with a bed at least 6" wide. I have found that different printers require that you scale the parts slightly for a perfect fit. On my Makerbot Replicator 2 I scale each part 104% for a perfect fit.
If you want to laminate the parts, I found this kit very helpful, Gorilla Works Carbon Laminating Kit, but you can also find high quality carbon fiber cloth, laminating materials and other supplies at Dragonplate and RC Foam
For simplicity's sake I am uploading all of the parts to bothThingiverse and Tinkercad. I re-designed most of the parts so that they can be edited in Tinkercad, which makes it simple to customize. I will post a link later to the uploaded collections of parts.
This drone uses T-Motor 3510 700kv motors with APC 12x5.5 inch props and a 10,000ma Multistar Battery. The T-Motors & matching 40A ESC's are efficient enough to use these low C rating batteries.
These images show only the frame, but there is a lightweight cover that is 1mm thick that fits over the whole rail assembly. The camera dome in the nose was salvaged from an RC Jet airplane, but I'm working on a new dome.
There is also a light weight cover for the entire drone that slides on in 4 sections. I'm in the process of reinforcing this cover with fiberglass and carbon fiber, and though it won't be waterproof it will be water resistant (more like a boat than a submarine).
The landing gear is interchangeable and I will be using 34" Foam Floats in this version.
This drone is going to be used in a demonstration for ABC News in the near future. I'll have plenty of video to post shortly.