CRAZYRYAN

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Hi my friend had an interesting idea of building a flying saucer that actually works like one lol but i have some good ideas that could make it work.

first off is the engine that you need to design around it. hes talking about building an rc version first then build a full three seater version.

my idea was to use counter rotating props that can produce enough efficient thrust and be capable of lifting it off the air at about 200 ft. but you will need to make an airgap or venting system to draw air from outside and be able to suck the air down wards like a vector. to control the movement of the craft the craft would have the whole counter rotating system be moveable in any direction so u have no limited axis. using gyros to help over correct the movement or it could stall on one side if banked over too much. does anyone know a way to actually start building using the correct material? my example would use aircraft grade styrofoam and later carbon fiber frame.

my other problem is to design a gearing box for the drive shaft of the engine to directly mount the two fan blades and make it counter rotate. is there a way to find resources or anyone know exactly how you could add gears to rotate the blades in opposite directions? i want a simple set up but its complicated enough to make it effiently and im just pondering right now if this is feasable shoot any ideas thanks!!!

tmojosh

Hey your project is doable but depending on what you want motor and prop setups will be completely different. If is was me I would want it to hover well and wven for wow factor the outside slowly rotate. If your primary focus is a stabile hover then two motors one faced up , and a pusher down facing. Though there are counterrotating motors the two must be spaced 6 to 8 inches from each other . The farther away the more efficiency , with blades 1 to 2 jnches from each other only gains about 30 percent thrust because its " unclean" air.

charlie111

The counter Rotating Rotor Blades are being used on available Models now.You could use most of the toy except the tail rotor.I think you said you were going to vector the thrust for control.You could cover the rotor blades with your saucer shape making sure to have plenty of air intake on top and vector the bottom side.Just thought I might give you some food for thought? I have re-invented the Helicopter and have a High Performance version nearly complete after getting the Bugs out of the 1st. one.I should have pictures of it in flight soon! Good Luck on the Saucer

tmojosh

Depending on how large you want this model will greatly change the equipment needed. I would say for vtol you need to keep the gross model weight well below 5 pounds , your goal probably 3 pounds but thats hard. Yes on ebay you can find contra-rotating dual blade 9 x 5 that actually has two motors one turns each blade. However they are not in clean air so they only produce 1-2 pounds thrust depending on rpm. However if you get two axi motors like 2814 and set them up to counter rotate just by pointing the second axi motor down in line with the first with a matching pusher prop. Also I recomend running the largest prop available width with low pitch , no more than 5 -6 in pitch. Ideal would be 4 in , and there are adjustable pitch units you can get 11inch and 13 inch in three blade so you can play with pitch. For vtol you need 1.1 to 1 thrust ratio , shoot for 1.5 to 1 because the little things like rx , rx batt , prop weight , wiring and mounts often add up to nearly another pound added to your flight wieght. Its 8 ounches for a 2200 mah battery , you will need two , one running each esc motor controller , I would recomend swift 50 amp brushless controllers they are only $25 bucks each. With two of these you could have 7 pounds or better of thrust with axi brushless motors. Taking into account 3.5 oz motor , 1 oz esc, 8 oz lipo battery = 12.5 oz per motor x 2 = 25oz thats 1.5 pounds for motor, esc and batteries that can produce 7 pounds static thrust. , that leaves 3 pounds + for radio rx , servos and framing

tmojosh

Fyi with the specs provided I assumed your flying saucer was going to be 18 - 22 inches , if you want 30 to 50 inches there is a different but similar approach but it costs prob 200 to 300 dollars more. You can use 450 size trex parts , get all of them from xheli.com which are trex clones and one third cost. You can have counter rotating variable pitch mechanisms. Use fixed orientation variable pitch for top blades , they with not tilt and provide gyroscopic stabilization , then have a 450 size heli rotating oposite direction for bottom set of blades , they will need to be at least ten inches from top set for clearance. The bottom set can tilt with swash plate and three servos , one for pitch , one yaw and one for rotor pitch. Both blades will spin at 3000 rpm contra rotation , they cannot be out of synce that is what allows to hover without your flyng saucer spinning uncontrolled. When the bottom rotor tilts the saucer will move and slightly tilt in that direction. It will fly like a heli but no need for yaw stabilation. Believe me I like in tennessee and people are ufo nuts . Whats cool is if you adjust the trim on the top rotor blade the saucer will spins slowly in place, cool effect, very mars attacks. The reason why you have vsriable pitch is as you increase lift the craft lifts in a smooth motion, smooooooth is the most important feature we are looking for, a disc wizzing around uncontrollable and unable to stop midair and hover just isnt cool. :> basically you would need two heli heads and matching blade sets , 4 servos , 2 brushless motors two brushless controllers and two battery packs if you want a list of parts to make it run real smooth let me know.