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Old Sep 18, 2012, 08:43 PM
Never fly an A model anything!
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Originally Posted by Stefan_Go View Post
I agree and I disagree. Understanding flight-dynamics basics, yes. But not understanding model-building (which my questions were circling around). There is a difference between only acquiring the knowledge necessary for effective (and safe) operations and learning tons of stuff that I'll never need and I'm not interested in.
As an example, to get a driving license for a car, I need to be able to safely operate it and I need to know the applicable legislation but I do NOT need to know how an engine works, let alone how to build one from scratch. There are many people who do because they are interested in that but not knowing the underlying technical details does not make me an unsafe driver.
This is not the place to argue but cars operate on the ground on massive infrastructure and under hugely regulated systems governing safety. If you were to take a car into the performance realm, then your understanding of the engineering and dynamic limitations would be more essential.
Your unfathomable comparisons to a car experience when you have said that light aircraft abound in your space underscore my concerns.

I will not clutter this thread any further with opinion on this.
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Old Sep 18, 2012, 09:04 PM
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Moved to PN
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Old Sep 18, 2012, 09:44 PM
Keep calm and carry on.
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Joined Jan 2012
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My point was that it takes many flights and lots of testing to get it tuned. The whole time you are flying manually, then testing autopilot, then recovering from inevitable danger manually, until you have it right.

There are lots of guys flying x8's with autopilots, including me.

Again, best of luck.
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Old Sep 18, 2012, 09:55 PM
Never fly an A model anything!
jayb1rdz's Avatar
Antarctica
Joined Apr 2008
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Stefan,
Despite my concerns, I should first say, welcome to the forum and apologies for sounding hostile. Not my intent.

I certainly appreciate that you have come here to get advice from guys that have huge experience. I have certainly saved hundreds, if not thousands by absorbing the insights of others here.
Ciao j
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Old Sep 18, 2012, 09:57 PM
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Ah, you meant, without having to control it manually BEFORE using the autopilot...
Sorry, English is not my native language. sometimes I miss details .

Back to my original questions - 30 series motor means 30-ish mm diameter, like e.g. Turnigy 3020B-600 or Scorpion SII-3020-890KV (just with more kV or a bigger prop)?
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Old Sep 18, 2012, 10:12 PM
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Originally Posted by Oso M View Post
Stefan

I love the ambition.

If you are going for pure autonomous flight you should really consider a traditional airframe (fixed wing, ailerons, elevator, and rudder). Not that a wing isn't great for autonomous, I just think you're going to be swimming in details without experience. Like trying trig without geometry. You could probably figure it out but will be slow and frustrating.

Great autonomous flight requires a good deal of tuning. All those PIDs are already challenging enough but without RC experience its going to be even more difficult. You might have read that a lot of people have difficulty tuning flying wings. There is just a lot of complexity in elevon mixing.

Unless you want to build a slingshot launcher you'll obviously need wheels for auto take off. You can however do auto landing without wheels. But again the tuning without a rudder might be tough.

Here's another topic people might debate me on. Endurance, I think a lot of people say that tractor props are more efficient in the long run. I don't know the aerodynamics involved to back that up though.

I hate to say this is as much as you won't want to hear it... But I would start with a smaller more simple airframe and get the basics of rc flight and all the moving parts first. Then move your gear into the X8 or something else.

Just some thoughts.
Autonomous is not synonmous to landing gear. As we have seen to operate auto does not mean it must TO & land convensionally. I intend mine to be auto eventually. Catapult with or without motor running when released and a parachute to land. Still all auto and still a reasonable choice frame for endurance. My 2c
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Old Sep 18, 2012, 10:23 PM
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When using a parachute, how do you control wind-induced drift between chute opening and touchdown (I'm thinking of the bird drifting to "bad places" like water or inaccessible areas / private ground / etc.)? Or do you choose an LZ where drift is negligible, like a wide plain area?
Whats the minimum opening altitude for a landing chute with a 3 or 4kg X8?
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Old Sep 18, 2012, 10:34 PM
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Quote:
Originally Posted by Stefan_Go View Post
Ah, you meant, without having to control it manually BEFORE using the autopilot...
Sorry, English is not my native language. sometimes I miss details .

Back to my original questions - 30 series motor means 30-ish mm diameter, like e.g. Turnigy 3020B-600 or Scorpion SII-3020-890KV (just with more kV or a bigger prop)?
Yes. I use a SII-3020-1110Kv on 3S for instance.
There are people throwing *much* bigger motors on this plane, but when emphasis is on
efficient cruise there's no reason to be adding all that extra weight.

ian
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Old Sep 19, 2012, 01:48 AM
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Originally Posted by Stefan_Go View Post
When using a parachute, how do you control wind-induced drift between chute opening and touchdown (I'm thinking of the bird drifting to "bad places" like water or inaccessible areas / private ground / etc.)? Or do you choose an LZ where drift is negligible, like a wide plain area?
Whats the minimum opening altitude for a landing chute with a 3 or 4kg X8?
I read somewhere that 15m/sec descent is reasonable...1 thousand , 2 thousand...15m,30, 45, 60m. Basically I think (operative word) 60 is a minimum height. There are is a sec or 2 before the chute fully deploys buy the glide scope on this plane with the motor off is insignificant. Chute design will make a huge diff on drift. No hole in it and it will drift. I have a chute from Fruity chutes very good quality (actually way over spec = heavy) it is their 60" Iris.The lines between the chute and the plane are about 7m so you need to consider that in the height. I believe with practice/experience you can estimate drift if the wind strength and direction are known. Fly up wind, release and visualise 3sec deployment, 4-5sec descent on a drift angle per the wind strength. None of this cannot be handle by eg diydrones APM.
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Old Sep 19, 2012, 04:20 AM
www.eahk.gr at Iraklion Grete
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Originally Posted by saabguyspg View Post
you can see my 31AP thread here..

http://www.rcgroups.com/forums/showt...575919&page=76

I love my FY products... yes there are some downfalls but so far they are the easiest to set up and they just work.

If you expect military grade performance then you are gonna have to spend lots more money

Steve
Ty man
No I'm not looking for military performance
I have 2 cameras One with sony-ccd for fpv osd and second is a HD camera from HK
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Old Sep 19, 2012, 04:26 AM
Auxerre - France
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Originally Posted by deTonaTor_NZ View Post
Thanks, the X8 slided in between Aluminium tongues. And yes it disassembles and is put into a bag for easy transportation.

Carl.
Really I will be interested if it works well to order one of it if you want to sell it of course !

Fab.
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Old Sep 19, 2012, 04:43 AM
Aalesund, Norway
Joined Jun 2012
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The FY31AP can do all that the Auto X8`s in the videos did, except from the landing.
But did that really look lika an auto landing..? The airplane flared. How can that be done without some kind of ILS or radar ?
And there was a guy with an RC radio. Maybe I am misunderstanding something

But my X8 has a low KW motor and 4S batteries. It flies really quiet and slow. Very easy to fly. VERY easy..
And about the car engine: You do not need to know anything about sharks to learn how to swim the great barrier reef. But it is highly recommended..
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Old Sep 19, 2012, 05:38 AM
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Originally Posted by daggad View Post
But did that really look lika an auto landing..? The airplane flared. How can that be done without some kind of ILS or radar ?
And there was a guy with an RC radio. Maybe I am misunderstanding something
Ultrasonic AGL-altimeter. Pretty standard stuff in the APM and the APM has an autoland algorithm. In the APM you can either plan a fully autonomous flight on the PC and transmit it to the APM or you can use a switch at the TX to change flight modes. Generally it could also be that the legislation in the country requires that the operator can switch to manual control at any time.

Quote:
And about the car engine: You do not need to know anything about sharks to learn how to swim the great barrier reef. But it is highly recommended..
xD, I see your point . You gotta love that Aussie-humor .
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Old Sep 19, 2012, 11:09 AM
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My folding prop does not have anything to push against going forward. Another words, you can physcially move the props far enough forward that they touch the trailing edge of the plane. Is this correct or have I got them mounted wrong? I did build a bracket to keep them from going over center to the rear
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Old Sep 19, 2012, 11:20 AM
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Originally Posted by jb_bak View Post
My folding prop does not have anything to push against going forward. Another words, you can physcially move the props far enough forward that they touch the trailing edge of the plane. Is this correct or have I got them mounted wrong? I did build a bracket to keep them from going over center to the rear
That's fine. Centrifugal force will keep it from going forward.
What is extremely important is that you have a prop-stopper to prevent
a blade from folding back past the center line. If it does, it will not swing open
when the motor starts and the severe imbalance will literally rip the
motor from the plane.

ian
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