I went through some crashes on my Quad, and this is my solution.
It worked real well, I don't buy props that often now days!
I tried to reply to comments, but my reply link does not work or that may be me, who don't know how.
Anyway, to answer comment; Carbon fibre frame is 0.33 pound, flying time with it is 16 to 18 minutes with 5000 3s lipo
total weight on Quad is 3.42 pound excluding battery. flying time is gained by 4-6 minutes without carbon fibre frame (tape off to remove).
I have not thought about making a kit (It took me a lot of time + itchiness from carbon dust, headache from fume of epoxy). if there is demand, may be.
Quad is now very stable in NG code, PID tuning was very difficult though.
How I built is in my own comment on my blog along with some pictures.
Motor is e-flite 1020Kv, esc is e-flite 30 amp, prop is apc 12x6P electric. Video cam is 520CCD OSD & 5.4 Ghz Video Transmitter from DPCAV, 12CH Futaba T12FGH.
Comments
CF is hard enough to reconstruct - If you plan on crashing often, I would consider putting some more flexible foam covering on the outside, a 1cm thick strip of EPP perhaps.
The main question is, how does this affect maximum endurance? Is it flyable without the external frame to compare? 16 to 18 minutes is a lot.
I really like this ARDrone like CF "bumper".
Offtopic: did you consider using lower pitch props?
I did not think this is going to generate that much interest, and I just realized my old Iphone's picture quality is horrible.
This is picture of my first protection frame that I build by using drywall tape epoxy over Dow Corning's 1" thick styrofoam was cut in shape. This served me well for all that crashes I had until I realized that I need something lighter and flexible to absorb impact.
and this is layout for carbon fibre frame cut out. (I used center section for support to hold four carbon fibre ring and laminated with carbon fibre.
Carbon fibre ring was made over cut out circle of styofoam with 1" cut strip from roll of carbon fibre cloth & masking taped over one side to hold carbon strips in the place (without tape applied first carbon fibre cloth will come out piece by piece in the cutting process), epoxyed first layer, let it dry, removed masking tape for all 3 layer. (Yes it is 3 layer 6oz carbon fibre cloth), then cut it out from styrofoam and sanded a lot.
Inspiring result.
Hope you tell more about-it.
How did you manage to build the structure to include propelers protection rings?
For a glass/carbon fibre nubie like me would be cool if someone did a tutorial on the stuff. Love to give it a go.
and how much does it weight?
very nice!