This system provides a lightweight, simple, full protection top bottom and sides. This is not a guarantee by any means, but my 5 year old boy has been able to safely crash with no damage so far, actually I crash harder than him but still, no issues yet….
Find two guitar strings, you can get two sections out of one string giving you four, one for each hole I’m using a A string (low E or a A depending on the gauge you buy) basically you want it to be just thick enough so that the wound section wont go thru one of the four corner holes on the crazyflie.
Cut them down to size, I have had pretty good success with 7 inch wire end to end, Including the exposed section
Unwind and remove the top winding of the guitar string exposing about 3/4inch of the straight wire inside, keep the measurment the same on both ends. This helps with balancing and keeps it easy to use
Find center on the exposed wire and bend the end just slightly maybe around 20˚ lay the string on a flat surface and bend the other side the same so that they are both pointing in the same direction.
Attach by sliding the exposed wire down thru one of the corner holes, wrap around in a loop and slide the other side up thru the same hole.
Now with the bent wire modification (3a.) this gives us a post where we can now attach some small rubber bands adjacent to each other or criss cross, (I used some really small very elastic bands my daughter uses for her hair) attach on top and bottom for best results.
Bonus these bands now also hold the battery in-place and provide extra protection for the motor wires.
You don’t have to bend the wires or use rubber bands but with the bent wire modification (3a.) This fixed the problem of having them pop out and also keeps them in line, now I have to make very small adjustments after a pretty heavy crash.
The smaller the wire the better for weight issues, but you want it just long enough to protect the propellors.
So far the the wires I’m using have not had much of a weight issue and provide a really nice springy protection for the crazyflie TOP and BOTTOM.
Im using a Logitech USB dual action, with raspberry pi headless and it works fantastic, but thats based on just plug and play, I don’t have anything to compare it with as far as performance but it works for me, once I start playing with hacking this thing I may run into some issues I will note them, If you have any comments or issues you have had let me know thanks….