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-   -   Crazy ideas and all dimensions flyer ? (http://www.Wattflyer.com/forums/showthread.php?t=73701)

solentlife 05-06-2014 02:13 PM

Crazy ideas and all dimensions flyer ?
 
We've got fixed wing planes that fly ... but need to keep moving to do so. We have Helicopters and Multi-rotors that can rise vertically and move horizontally.

Now we know there are various full size machines and models that can combine both.

My post is to start a thread with ideas of how to combine models .. ie a quad and a fixed wing to produce a dual purpose verti-plane .. would that be a good name ?

Lets say you took a quad .. bare rod frame .. not a bulky job like some are. Then build a plane round it .. the rotors being in circular cut-outs in 4 wings ..
A tractor or pusher prop motor at end to give the forward movement .. or even backward as well if you can sort.

So we get vertical take-off .. and transition to normal flight ...

??

Anyone game ?

Nigel

Wrongway-Feldman 05-06-2014 02:34 PM

Check this out
https://www.kickstarter.com/projects...-landing-airpl

Is this what you have in mind?

Also check out the flitetest seff 14 video. It's a little long but it has a great part about a guy that scratch built a working VTOL.

Looking forward to see what comes of this.

fhhuber 05-06-2014 02:40 PM

The main issues with VTOL "fixed" wing aircraft have been power and stability. The power issue got covered long ago. The stability issue is covered by modern electronic 3 axis stabilizer systems.

All that is really left is to improve performance.

solentlife 05-06-2014 03:00 PM

OK .. tks first for not saying I'm a nutter !!

Why am I asking ...

I have recemtly started flying quad .. little Banggod jobbie. I also fly Fixed wing as most know.

I appreciate the little 959 will not lift a reasonable fixed wing model - but there are quads out there which will.

So how to combine them ? Which is why I posted .. a rod based quad with a fixed wing job built round it. If it's a flat plate depron job .. surely that will work ..

Lets say you build an F16 / F15 style flat plate job with enlarged tail stabs - so the rotors can fit in the area of stabs .. as well as the forward two into the main wings...
ie basically 2 main wings connected by fuselage .. with quad sitting in it ..

Strap a pusher prop on the back or a tractor prop on front .. bingo !

The quad is configurable on most radios such a 9xr and higher Spek's to be controlled by pots or switched in / out .. etc.

C'mon .. bit of imagination - what can we do ?

Nigel

Yes - I'm stuck in Ukraine and minds thinking !!

pizzano 05-06-2014 04:14 PM

Take a look here:

http://www.rcgroups.com/forums/member.php?u=168745

http://www.rcgroups.com/vtols-360/

solentlife 05-06-2014 06:02 PM

Great links .. bit iffy about the saucer .. but..

Wattfflyer - can we knock up something a bit different ?

My thoughts are a stable vertical lift and the power up propulsion to fly off .. transitioning from rotor lift to wing lift ..

Nigel

hayofstacks 05-06-2014 06:10 PM

Take a slow stick, mount two 300-450watt motors on the end of each wing, then put one smaller motor at the tail to give you the equivilent of a tri copter control system. keep the front motor for forwards propulsion and your done. id probably run two 400 size motors counter rotating on the tail hooked up as a singular channel.

vtol and landing, hoverable, and enough wing area to fly forwards. if the wings don't produce enough lift, up the trims to the main wing motors.

thepiper92 05-06-2014 06:11 PM

Hmm interesting ideas. When the Twin Contest came about, I random started thinking about a twin wing, with one motor in the front and one in the rear. These two motors would be mounted to a pivoting mount to cause the motors to go vertical. The middle of the wing would have a hole through it to allow air to pass through. These props would be counter rotating, and thus the plane could be prevented from turning. If one wishes to turn, one motor would increase power, the other would lose power and the plane would turn. Then one could move the mount at an angle and have forward flight relating to the angle. Then, if one wants wing lift, simply pivot the mount horizontal. Probably a bad idea, but I suppose could work.

solentlife 05-06-2014 06:27 PM

Forget with twins .. too many iffs about stability.

Best with 4 rotors and a pusher up the back .. or prop on front.

The 4 rotor system is available out of box .. all you need to do is marry the airframe to it.

Control can be combined quad system to the airframe std Rx .. a 9XR could do it .. say vertical by rotary pots .. then flight by sticks ..

Just idle thoughts that need fashioning into a real plan ..

Nigel

thepiper92 05-06-2014 06:38 PM

What if you could pivot the two rear rotors, or two front ones.

solentlife 05-06-2014 06:51 PM

1 Attachment(s)
Ok .. here's a sketch .. just a quickie mock up ...

Nigel

thepiper92 05-06-2014 07:16 PM

How would cg be though. On a plane, the nose is technically heavier to allow balance at 25-30 of wing, but with a quad idea, you'd need more power on the front rotors than rear, or more thrust from the props. Would this not cause some banking and turning issues, due to all the front being more powerful than the read. To me the easiest way would to have vertical propulsion at the cg point.

Perhaps implementing a form are canards so the quad portion moves forward and its mid point sits along the cg line. With how it is now its seems you would actually be adding tail weight, and thus need more nose weight, perhaps leading to a quad with too little thrust for its weight. I speculate in such a design a tractor is necessary, not a pusher.

fhhuber 05-06-2014 07:22 PM

Simple.. use bigger motors and rotors in front. That handles the heavier load in front. The programming of the quad stabilization board wouldn't even notice.

Yakfishingfool 05-06-2014 07:22 PM

put the motors on rotational bars that sit within the wells. Balance would be interesting unless you could use a servo to shift weight from center to forward.

thepiper92 05-06-2014 07:33 PM

I think shift the quad forward would help to avoid added tail weight... Unless the control board was moved well away from the quad portion. I imagine tricky wiring no doubt. Maybe a tricopter design that pivots the rear motor horizontal and you could even use thrust vectoring

xmech2k 05-06-2014 08:02 PM

I can't find it now, but I saw some teens made a cool quad tilt-rotor in the style of the Curtiss-Wright X-19.
http://upload.wikimedia.org/wikipedi..._X-19_1963.jpg
It was made simply of flat foam with perhaps some structure for rigidity, and the fuselage was more boxy than the X-19, and it was amazing. They had some smarts, because they had to make it use the normal quad stability system when the props were vertical, then switch that function off and used regular flight controls in forward flight. They had a great video showing it flying and transitioning very successfully. I saw another video with a bit of a demo at an indoor event as well. Wish I could find it again.

solentlife 05-06-2014 08:31 PM

I think fhhuber has it ... the stab board will handle that.

The quad rotors don't actually have to stop .. they can stay balanced for level hover ... the only problem comes when you want to turn or pitch up / down.. IF you revert the plane to standard controls.

BUT if you use the quad rotors to provide the 'yank and bank' .. then you are halfway to success..

Piper and you lot have made me look at it from the OTHER side. Initially I looked at Quad to only do vertical and then plane would revert to conventional flight. But in fact if you use the quad as lift off ... and as means to turn / pitch up / down .. then all the conventional plane part needs to do is propel the model forward.

So instead of putting the Quad on the pots - I would put the conventional motor on a pot .. and the Quad on the sticks. Of course conventional ailerons / elevators can be mixed in as well to keep the conventional boys happy !!

I think it's coming together ..

Great stuff ...

I know there is actually a model produced by one of the Chinese factories similar to this .. never actually seen one in the flesh - but remember a few adverts on here or RCG .. I'm not really interested in a factory solution .. the fun is putting this together from OUR ideas !!

Cheers
Nigel

solentlife 05-06-2014 08:33 PM

Oh and doing it that way - no need for tilt rotors or Thrust vanes .. plus the CoG bit is basically solved ... you just balance the quad as centred to the airframes CoG limiting the difference of ends ...

Nigel

Wrongway-Feldman 05-06-2014 10:24 PM

Very interesting ideas.
I was thinking perhaps instead of a X configuration for the quad layout a + instead.
Two larger rotors in the wings with a smaller rotor in the nose and tail.
Perhaps even 4 small ones all around.
The 2 in the wings would tilt for traditional flight providing forward thrust while the nose and tail rotors could either spin down in traditional flight or could even be used as pitch control.
As I imagine it this layout would look the most like a traditional plane with the added VTOL capabilities.

solentlife 05-07-2014 05:46 AM

I know I said I was trying to avoid an out of box model ... but that was with regard to the finished job. There are already combination models out there... RTF / ARF.

But for the quad part - I think an out of box for that is best. Or at least an established design.

I feel the rotors in wings, (4 wings) is best as the rotors will be quite large and difficult to set inside a fuselage width.

I also feel that tilt of any rotor is not needed if the full rotor functions are maintained. The pitch is obtained by differential front pair to rear ... bank is obtained by differential side to side. Forward motion by a conventional prop ...

Nigel

thepiper92 05-07-2014 06:16 AM

I was thinking that tricopters are much better fliers, pivoting on the front rather than middle, and perhaps the rear prop could be made to go horizontal it could be the pusher itself, and have thrust vectoring in of itself. With this you could program the quad to pivot the quad on rudder rather than aileron, may even eliminate banking, having just pitch, pivot and thottle. This would allow you direct transition into plane mode, and use thrust vectoring for rudder. A mix of sorts could turn off the front rotors when the rear goes vertical. I feel tri would also keep less weight on the rear, as well as allowing you to not need an extra motor.

solentlife 05-07-2014 07:01 AM

So .. OK .. who's up for a build then ?

Seems already we have differing schools of thought - excellent - more the merrier. Whole point is to evolve and develop a working concept .. and maybe actually build and fly ...

Anyone ?

Nigel

solentlife 05-07-2014 07:41 AM

My plan of action :

Based on the sketch I posted earlier ...

4 x donkey motors with suitable props (most likely 6x4 or similar)

Arrow shafts or alloy sections .. 2 of - one across each wing / fuselage / wing section to lock the rotor mounts to.

6mm Depron

Quad controller

small to mid range motor for forward flight.

Park Rx to control additional elevators, ailerons and motor.

All control to be mixed into a 9xr ..

Vertical lift by 4 fixed rotors .. bank and pitch by same = Quad controller / gyro stab. The bank and pitch commands also mixed to ailerons / elevators of Park Rx.
Forward flight by pot controlling ESC of single propulsion motor = Park Rx

I still reckon there is no need with this above - to have any tilt of rotors .. the 4 rotors via the standard quad / gyro board will stabilise the model ready for transition. Keeping the quad controls active while flying forward will stop the gyro system fighting the models manoeuvres.

Nigel

fhhuber 05-07-2014 04:35 PM

You probably won't go fast enough for it to be an issue, but there is an effect of using rotor lift (helicopters) that limits maximum airspeed.

Even turning off the quad system motors you'd still have to deal with that effect as the props windmill. If you could guarantee the props stop with the blades aligned fore-aft you might be able to avoid it.

thepiper92 05-07-2014 05:22 PM

Possible to add motor brake on the rotors perhaps.


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