I am new to this so I have a lot of questions. Some might be quite obvious, others not :)
In the long run I would like to be able to build an extremely stable quad with:
- Autopilot with complete two-way comunication like the ArduCopter and a ground station + fpv
- Gyro stabilized gimble with camera with zoom.
- Camera facing fwd for flight, with complete osd-system (power consumption, position, and so on.)
- Flight time should be quite long, more then 30-40 minuttes. I need to go from 0 to 1100 meters, do the photos and videos, and then return. More or less straight up and then down again.
- Shuld be capable of handlig 6 m/s wind with some more for gusting.
As you all see, this is not a starting point. This is number two... or maybe number six... or later :)
I have been playing around a bit with Autodesk Inventor. I do this as a substantial part of my daytime job, so I threw together a 20 minutte model for illustration only.
I have some questions:
- Pitch and roll is achived by altering the torque/rpm of the engines. One increases, and the diagonal one decreases. Is yaw achived by altering the two rotating in the same direction to allow torque to do the yaw rotation?
- I would not build a quad to travel distances. (Then I would build a plane.) I want it to be stable to allow fpv quite from the start. Should I get the CG above the rotors, or below? Modern fighters have an unstable design to allow for quick manouvering. A cesna 172 have high wings to allow the CG to be below the center of lift. The big difference being that the pilot flies a cesna and asks the computer in an f-16 if he can fly this or that way :-) More or less the same as I would ask the ArduCopter to do. So should the CG be above or below the rotors to help stable flight?
- Shuld I try to move as much weight as possible to the center, or should I move them out to use the mass to stabilize?
- I have made the model with the skid mounted to the center. Is this wise? It would maybe help reduce vibrations compared to a design with skids mounted on the boom?
- I have a black ball below the center. This is just to illustrate the camera. Is this a position to go for? Or shuld the camera be mounted between two booms, with battery or something else compensating on the diagonal?
- Should I mount a beam between the motors to reduce vibrations?
- How much would something like the ArduCopter 3DR Quad (http://www.udrones.com/product_p/acrtf2.htm) lift, and what flight times should I expect?
I hope that someone would be able to give me some guidance here :)
A lot of questions, but if you have some replies to some points, it would be extremely helpfull :)