Beginners: please read this post and this post before posting to the forum.
0 Members and 1 Guest are viewing this topic.
Quote from: airman00 on February 03, 2008, 09:38:11 PMno i mean a two bladed chopper like this top view would look like thisO-O So it would create a Chinook
no i mean a two bladed chopper like this top view would look like thisO-O
well... we do just one rc heli with coaxial rotor - Apache AH64 Longbowthe only problem is that i am not allowed to take it out of the box, charge it and play ;[the same with those Picoo Z - they came from returned packs, where the other one was broken.i use what i can, but i'd love to be able to 'test' some better stuff ;p
I think if you make the diameter of the propellers bigger, maybe even double, and made the body a little bit skinnier you would have more chance of a successful build. You may have difficulty turning and such.
I am building some flying robots as well.
But no offence but from your CAD I dont believe your robot is going to fly. I think the body in the middle will reduce a lot the efficiency of the two motors. Have you tried to calculate the flux of air through the propellers. The fluid lines(I dont know how to say those in English)? Not to mention that that body is difficult to build. I am not a mechanical engineer so I cannot expleing everything in detail to you but as a bio-system engineering student I studied some basic mechanics at college including fluid-dynamics. And I can tell you that in order to build high-speed, flying or under-water vehicles and robots, some basic knowledge of flui-dynamics is fundamental. I am not telling you to buy the thickest book in the book store about fluids. Just use google and get some idea about aerodynamic principles. I think ADMIN knows about this stuff much better than me. He is a mechanical enginer and is building an aquatic robot.
also i don't think the propeller on the bottom is a good idea. i think if the propeller on bottom is even a little bit slower (or faster) than the one on top it will do flips.
Also the body is to fat and will catch wind to easily.
It looked to me like the propeller on the bottom is intended to counter-rotate to alleviate the need for a stabilizing rotor.
And depending on the resources available the body is doable.
it may fly I don't think it will. also, wouldn't it be confusing when the robot flys since you wouldn't know which is forwards?
Even if it does fly, that thing will be as stable as a jet-propelled brick, which would require hundreds and hundreds of dollars and the most difficult coding imaginable to keep it in the same place for more than half a second.
For the "if it drifts anywhere, go back" part you would need to use GPS and have the robot monitor its GPS coordinates and if it sees a change in its latitude, go the opposite corresponding direction, etc, etc.
I think the easiest way to go would be a standard chopper design. That way, up and down is controlled only by one rotor, and turning is controlled by another. Both independent of each other.....
tired. must stop typing.
The Chinook is powered by two turboshaft engines, mounted on either side of the helicopter's rear end and connected to the rotors by driveshafts. The counter-rotating rotors eliminate the need for an anti-torque vertical rotor, allowing all power to be used for lift and thrust. If one engine fails, the remaining engine can drive both rotors.
OK guys, this thread is starting to get sorta off topic
how will the darn thing hover autonomously?Once we get that set straight , then we'll talk about GPS and sonar ,etc.
I propose three blades , but maybe there is a better wayAfter doing some research on the chinook helicopter I found that it works like thisQuote from: WikipediaThe Chinook is powered by two turboshaft engines, mounted on either side of the helicopter's rear end and connected to the rotors by driveshafts. The counter-rotating rotors eliminate the need for an anti-torque vertical rotor, allowing all power to be used for lift and thrust. If one engine fails, the remaining engine can drive both rotors.It has two blades on top for lift and two jet engines pointing backwards for thrust forwardMaybe we should make two blades for thrust and two fans in back for thrust...what do you think?
This configuration also has the advantage of being able to hold more weight with shorter blades, since there are two sets. Also, all of the power from the engines can be used for lift, whereas a single rotor helicopter uses power to counter the torque. Because of this, tandem choppers are among some of the most powerful and fastest. The CH-47 Chinook for example, has one of the fastest top speeds of any helicopter in service.
it has to hover in place that is a must , you can't have it just flying around everywhere. Hovering is a must!!! that should be done first!!!!
what about this design?
You can have a servo tilt the blades