Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: KaweS on January 31, 2008, 02:13:01 AM

Title: Building a Flying Robot
Post by: KaweS on January 31, 2008, 02:13:01 AM
hi,
i'm new to robotics as well. my advantages are that i can program in C [for computers, but someone already did mention it will take me a day to learn in] and i can spend a bit more ;p
my disadvantage is that i didn't even build a $50 robot ;p
i built just a 'vehicle' based on 2 CDs, polyester body and a DC motor form my ex-CD-ROM ;] it can go forward and even backward if i change connections ;ppp
i know that's nothing, but i'm a bit ambitious and i learn really fast if i want to learn something

i'd like to build a robot which can fly [preferably with wings - not rotors] [see: http://www.youtube.com/watch?v=U5hGYWVdzVk] but definitely not r/c but autonomous. i want it to fly around me and avoid obstacles.
i guess i'll need lots of sensors and quite good ic.

ok - now the questions ;p
how can i tell the robot where am i? satnav or what? ;p i don't expect to come to me hundreds of miles, but let's say from my room to kitchen ;p i want to put for example plan of my flat and use wavefront algorithm - is that a good idea?
what kind of ICs could i need? i think lot's of memory and fast processing time - maybe 8 bit is not enough?
what materials can i use? what for body/wings?
what about flying time? i don't want it to run just for 5 minutes... i know - more power - heavier batteries
what about costs... i know i cannot expect too good news regarding this point ;p

to be honest i'm thinking already about version 2, but for now that's enough ;p

thanks a lot for any help and ideas ;]

cheers,
Karol
Title: Re: Building a Flying Robot
Post by: skatj on February 01, 2008, 12:14:57 AM
Umm, an ornithopter, especially of that size, and indoors, would probably require a great deal of experience before someone would even think about working on it.

I suggest starting with a fixed-wing aircraft based on an inherently stable airframe that uses a GPS receiver as sensory input.

expect to spend 600$+ for that.
Title: Re: Building a Flying Robot
Post by: frank26080115 on February 01, 2008, 12:43:11 AM
Although your enthusiasm is great, you need to crawl before you walk and walk before you run, and a flying robot is like riding a bike if running is compared to a home built hexpod.

If you must make a flyer, I'd suggest making a lighter-than-air robot like a blimp, exactly the same as a wheeled robot except way less mechanics to worry about, just keep it light.
Title: Re: Building a Flying Robot
Post by: SmAsH on February 01, 2008, 02:30:59 AM
a blimp? as in filled with helium and the motors underneath? thad't be cool
Title: Re: Building a Flying Robot
Post by: KaweS on February 01, 2008, 02:37:37 AM
i expected those replies. i know that is a huge jump over all the basics which i should practice, but i think i'm able to do it. but on the other hand i'm not in rush so i can do some more basic robots. just suggest me what could be helpful - i don't want to build a car with basic sensor just to learn how to avoid obstacles. do you really think it is necessary?
what more - i don't want it light - it has to be quite heavy, cause i want it to fly outdoor... so if that is possible [i could require really big wings] i want to fly it outdoor. if not i'd rather go for rotors. i want to keep it as small and heavy as possible ;ppp i know that i'm asking for impossible... and don't forget that i want it to fly for quite long time [1st post]. so if it just can't be done - i'll stay with light flier for indoor use only.
what about a blimp? nice... but not for me. i want it fast in movement and changing directions and i think it's impossible with a blimp.
i live and work in UK, so 600$ is not a big deal for me ;p

cheers,
Karol
Title: Re: Building a Flying Robot
Post by: SmAsH on February 01, 2008, 02:39:55 AM
lol yer you brits can afford everything of ours. anyway...if you want it heavy i would suggest atleast 4 powerful motors with BIG blades. you may be lucky.
Title: Re: Building a Flying Robot
Post by: airman00 on February 01, 2008, 08:07:00 AM
quadricopter or tricopter

first worry to make it levitate autonomously , no moving yet

have the blades tilt for propulsion
Title: Re: Building a Flying Robot
Post by: JonHylands on February 01, 2008, 08:35:44 AM
If you're set on using wings for flight, I would strongly advise you to buy one first, so you can get an idea of how well they work, how much they weigh, and how the wing mechanism works.

http://www.hobbytron.com/CyberHawk-Ornithopter.html

Whatever route you take, to get to where you described in the first post, expect to spend at least a couple grand and a couple years...

- Jon
Title: Re: Building a Flying Robot
Post by: gmatkins on February 01, 2008, 09:35:01 AM
You might be able to hack a WoWee dragonfly. They're cheapish and they sure fly. To save a little weight try putting it's brain somewhere off-board and have the brain talk to the body via RC or IR. If you were willing to wear they transmitter on your body (and it could be quite small) then sensors on the dragonfly's body could use the signal both to receive information and to keep track of you.
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 01, 2008, 11:43:27 AM
If im not mistaken, you said you wanted to make something that flew like a regular airplane as opposed to a helicopter? That wouldnt work in and indoor setting. It would crash into everything and anything.

Basically for autonomous navigation and avoidance like that, you would probably need image recognition rather than just range finders. Range finders can be fooled and mislead. That is very very advanced. Like some of the others said, first work on making something that can simply rise straight up and then land again by going straight down. Perhaps using a range finder on the bottom of it so it knows when its about to hit the bottom so it can ease its velocity to about .1 m/s or so to reduce the shock of landing... and also some compression springs on the landing gear to help with that also.
Title: Re: Building a Flying Robot
Post by: KaweS on February 02, 2008, 06:29:38 AM
thanks for all the responses ;]
just a quick note to be clear what i'm looking for. i want a craft what can hover and move all the directions like a helicopter, but i'd like it to use moving wings, like a bird.
cyberhawk looks cool and i love one point from it's description - 'So realistic, you'd swear it could drop a load on your head!' hehehe
anyway i think it will be to difficult to develop and take too much time on experiments on most efficient design, so i think i'll stick to rotors.

1st problem which i need to solve is the design. do you know any proven architectures? [yes - helicopters] ;]
2. batteries - i read a bit and i found out that the LiPo batteries are the best for air-crafts. please correct me if i'm wrong.

the idea with brain out of the body is quite good, but where could i mount it? carry it with me? what about transmission? wi-fi? and i guess i have to put some basic intelligence in it in case of lost connection - i cannot allow it to crash ;p
what about GPS? i read a bit about it and hi-end receivers can pinpoint object to 2-5 meters, what i think is not enough. for instance if i'm in another room and i want it to come to me it will not know where to go... what about levels? what if i'm above or below it - on another floor? i live in a maisonette...
any other ideas for positioning?

//EDIT
[youtube]sN7jz7P7p1Y[/youtube]
i just found this vid and i think that's just awesome. i didn't know that something like that is even possible. how can it hover? shouldn't it just spin around? that's why helicopters have tail propellers...
that would be great for my robot. it would move vertically when precision is important and horizontally to go fast
Title: Re: Building a Flying Robot
Post by: dunk on February 02, 2008, 10:17:44 AM
hi KaweS,
your not making things easy for yourself.
what you are describing is taking 2 of the harder unsolved aspects of robotics and combining them.

indoor localisation is not an entirely solved problem. on a stable ground based platform it takes people years of research.

autonomous aircraft are very difficult as well. people have managed to make rotor platforms that can keep them selves level but it a non trivial task and flight times are very short due to battery life.
again, be prepared to spend a lot of time and effort building a platform that can take off and keep it's self level.
look into balancing segway style robots for more information on the types of sensors you will need to use.

Quote
how can i tell the robot where am i? satnav or what? ;p i don't expect to come to me hundreds of miles, but let's say from my room to kitchen ;p i want to put for example plan of my flat and use wavefront algorithm - is that a good idea?
Quote
what about GPS? i read a bit about it and hi-end receivers can pinpoint object to 2-5 meters, what i think is not enough.
2-5 meters is only out doors. satnav is no good indoors. if you can find a sensitive enough GPS you might be able to get resolution down to 20-25 meters or so indoors.
if you are prepared to drop your indoor requirement then GPS may be an option for you.
there are no easy ways to determine your robot's position inside.
the easiest method would be to fill your house with beacons and have an onboard map of your house and where the beacons are.
another method would be to use ranging sensors and use pattern matching against an onboard map of your house in an attempt to determine where your bot is. this approach is hugely processor intensive and difficult to achieve, especially with the limited lightweight sensors you will need to use on an aerial platform.
bear in mind you are going to have huge problems getting accurate sensor readings from a moving flying platform.

although i'm not suggesting you use it, search this forum for SLAM (Simultaneous Location And Mapping) for a little insight into some of the problems you will face.
you will face similar problems with the advantage of already knowing the layout of your house in advance so you can start with a known map.

Quote
.what materials can i use? what for body/wings?
what about flying time? i don't want it to run just for 5 minutes... i know - more power - heavier batteries
what about costs... i know i cannot expect too good news regarding this point.
look around on Radio Control forums.
top end ready built electric RC helicopters can run for a maximum of around 30 mins on LiPoly batteries. i would expect far less from a home made platform.
as for price, this is going to cost you many $thousand as there is no way you will get it right on your first attempt and will undoubtedly end up re building many times.

as you might have guessed, i don't think you will get very far treating this as your first project.
i think you would be far better working on the different challenges independently with the aim of building a flying bot once you have some experience in the technology involved.
as a first project start trying to build a working microcontroller platform that can control servos and RC motor controllers. for someone with the experience you describe this will be non trivial.

next use it to control your wheeled vehicle so you can experiment with sensors and map solving on a ground based platform. i'd be surprised if you get a ground based system that can locate you on it's own within a year.

next i would experiment with angular rate sensors and acceleration sensors to try and build a balancing segway style bot. you will need good understanding of these sensors to keep any flying platform upright.

anyway, good luck with it but seriously, you will have far more success if you pick simpler objectives to learn about the technology involved before starting on your flying bot.


dunk.
Title: Re: Building a Flying Robot
Post by: KaweS on February 02, 2008, 06:08:47 PM
i didn't realized it could be that difficult...

do you think that i should build a heli first and then try to create a plane from it? [ok - i'll create a wheeled vehicle first, just to learn basics, but after that]

indoor localisation.
i'm thinking about making my robot able to recognise area - the room where it is at the present moment. i have no clue how long would it take and how much memory consume... [i think about... let's say 3-5 inches cubes] it should remember some areas even after switching it off [all rooms in my flat, my workplace...]
when it has a 3d map of area and it's able to go any direction i think it will not be to hard to find and go the quickest way from A to B.
i think i need to use different sensors altogether to create such a map. and it has to move around to recognise all the area. it needs to be able to check the way it goes to avoid hitting moving obstacles. what about tracking other objects? if it detects collision course it needs to find another way or just hold. but this would be very difficult and consumes lots of power...
i can install another thingy on me to recognise the area and then send info to the robot which obstacle is me ;]

what kind of sensor would be useful/necessary?
accelerometer for sure
color sensor? i think it's useful, but not necessary to work
compass? i have no clue what could i use it for?
encoders - yes
force and torque sensors - yes
Sharp IR Range Finder - lots of ;]
sonar - i think sharp ir is enough
something else?
Title: Re: Building a Flying Robot
Post by: airman00 on February 02, 2008, 10:27:30 PM
first make a quadricopter or tricopter that can hover autnomously , then well talk  ;)
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 03, 2008, 12:17:44 PM
~To affectively achieve what you are talking about here, I think what you would need is cameras and image recognition... which is a huge deal.
~You would need an accelerometer of course, yes. To determine how fast it is going parallel AND perpendicular to the ground (2 seperate accelerometers).
~Color isnt really TOO important for a robot unless you want it to track and follow and/or shoot at a specific color... or perhaps I identify specific color coded markers.
~A compass would be required so the robot knows its heading in relation to the map in its memory
~The encoders can be used on the rotors (of a heli, please dont even try to make a plane out of it for indoor use. That could be disastrous) to monitor the RPMs. This is handy for a number of different reasons.
~To get the amount of force you will have to plug the amount of RPMs into an equation involving the amount of air moved per rotation of the blades and the amount of rotations per minute(or second).
~For the Sharp IR, this could be used to sense the distance between the bot and the ground, ceiling, so it doesnt rise or fall into anything... like a ceiling fan or something :P...
~Sonar, IMO, would be better for use on the front and rear of the craft so that it can detect objects in front of and behind it so it doesnt try to move forward or backward when something is in its way.
Title: Re: Building a Flying Robot
Post by: KaweS on February 03, 2008, 02:11:12 PM
thanks for your replay - it helps a lot ;]

but do you really think that sonars will be better than sharp IRs? as i read IR is not perfect, but still works. in the opposite sonars are very vulnerable to noise, in particular in places with not too much space around and lots of obstacles.

what about accelerometers, they can be even 3-axis. look what have i found on google: http://www.rapidonline.com/productinfo.aspx?&tier1=Electronic+Components&tier2=Integrated+Circuits&tier3=Sensors&tier4=Digital+MEMS+3-axis+accelerometer&moduleno=79653&catRef=82-1006 (http://www.rapidonline.com/productinfo.aspx?&tier1=Electronic+Components&tier2=Integrated+Circuits&tier3=Sensors&tier4=Digital+MEMS+3-axis+accelerometer&moduleno=79653&catRef=82-1006) and it's just £14. i just wonder if they work all the same. i know that i need hi-end cause it has to be quick and hi resolution response, to react fast.

compass? i think if it has a map, it is enough, because on the map doors will be located as well and depending on readings from sensors it will know where it is at the moment and which direction it has in front of it. compass could make it faster to recognize at the beginning, but it's more to implement, when after few readings from sharp IRs or sonars it will localize itself as well.

cheers,
Karol
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 03, 2008, 02:13:55 PM
Dont have much time to explain at the moment because I have to leave but:
The sharp IRs are very much directional but the sonars have a wide angle of detection when in a stationary spot

I would have the compass still. I wouldnt rely on the positioning of objects to find your heading. This is extremely difficult not to mention very system intensive.
Title: Re: Building a Flying Robot
Post by: SmAsH on February 03, 2008, 02:17:10 PM
but would a scanning ir work?
Title: Re: Building a Flying Robot
Post by: cooldog on February 03, 2008, 02:46:09 PM
but would a scanning ir work?

yes but i's really heavy for a flying robot
Title: Re: Building a Flying Robot
Post by: airman00 on February 03, 2008, 04:16:04 PM
well today i was playing around with my r/c heli with a camera mounted on and I realized that if you could have accelerometers relay info back to a PC over bluetooth or something , then the robot can autocorrect for human errors. If the heli sees its going to crash it can autocorrect the human operators mistake.


Or even easier, since I have a wireless cam on it , I can output the values of the sensors onto an LCD on the heli and then use roborealm to convert the visual numbers into data numbers.
http://www.roborealm.com/tutorial/Digital_Reader/slide010.php (http://www.roborealm.com/tutorial/Digital_Reader/slide010.php)

What do you think?
Title: Re: Building a Flying Robot
Post by: KaweS on February 03, 2008, 06:48:14 PM
i need to say that i'm a bit surprised of myself. to be honest most of my projects [any kind of] i never finish when it comes to learn new stuff ;p but today i spent many hours studying helicopters - how do they work and so on. generally last week i learnt lots about robotics and related stuff and i still want to learn more ;p i just printed many pages regarding helicopters and hopefully i'll have enough time to read it at my work ;p

i think that i'll buy an RC heli to hack it or at least some parts of it - rotors and engine
i think i'll skip a quadracopter or a tricopter. tomorrow i'll read more about various types of rotor systems and then i'll decide.

i still don't know what about sonars and IRs - instaling 8 around plus another two - one on the top and other at the bottom or some sonars - no idea how to locate them.

compass - honestly i don't really think about it now.

camera on my heli? for sure, but not yet ;]
airman: keep developing and share your results so i'll use them when it will be the proper time ;p
Title: Re: Building a Flying Robot
Post by: airman00 on February 03, 2008, 06:51:56 PM
well can I just get four r/c helis and connect them together and use those main blades?


something cool
(http://img.dailymail.co.uk/i/pix/2007/05_02/SauceDM2505_600x692.jpg)
Title: Re: Building a Flying Robot
Post by: airman00 on February 03, 2008, 07:00:45 PM
forget four blades


would two blades work?

basically two helicopters attached together
Title: Re: Building a Flying Robot
Post by: KaweS on February 03, 2008, 07:07:52 PM
i don't know too much about rotor systems yet, but
2 main rotors connected together - no - they both spin clockwise so you cannot use it.
2 helicopters connected together - somehow it could work - try to connect two the same helis, which work at the same frequencies, to each other and use one transmitter to control them like one - could be really nice ;] i'll try it when i'll be able - my manager won't be around and it won't be too busy

lil'bro looks crappy, but has nice abilities ;] try to find the frequency it works at and take it over hehehehe
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 03, 2008, 09:36:12 PM
lil'bro looks crappy, but has nice abilities ;] try to find the frequency it works at and take it over hehehehe
That would be hilarious

2 main rotors connected together - no - they both spin clockwise so you cannot use it.
You could reverse the polarity of one of the choppers' motors and flip the prop of that same chopper upside down. That would work.


That would basically create an Osprey (http://www.fas.org/man/dod-101/sys/ac/v-22.htm)
Title: Re: Building a Flying Robot
Post by: airman00 on February 03, 2008, 09:38:11 PM
no i mean a two bladed chopper like this


top view would look like this
O-O

the O being the blades

but try the two helis attached , tell us what happens
Title: Re: Building a Flying Robot
Post by: SmAsH on February 03, 2008, 11:22:54 PM
hmm yes that may work but youll probibly have a hard time changing the frequency.
Title: Re: Building a Flying Robot
Post by: hgordon on February 04, 2008, 07:05:59 AM
If you're serious about this, spend a few hours (or days) reading old posts here -
    http://www.rcgroups.com/multi-rotor-helis-200/

The problems you want to address are VERY complicated, and you need to develop a basic understanding of flight dynamics for different airframe architectures before you can begin to figure out how to integrate sensors and onboard computer controls.

That said, I will note that this is a VERY interesting subject area, and quite addictive.  I have 3 UAV projects in the works at the moment - 2 of them are described here -

    http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A23537
 
    http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A22738

As you can see, I'm still struggling with basic flight stability issues, so fully autonomous flight is still a distant goal, but I'm motivated.
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 04, 2008, 10:59:22 AM
no i mean a two bladed chopper like this
top view would look like this
O-O
So it would create a Chinook (http://www.enemyforces.com/helicopters/ch47_chinook_2.jpg)
Title: Re: Building a Flying Robot
Post by: KaweS on February 04, 2008, 12:44:29 PM
i've got some cool stuff for you guys
just gimme few minutes to upload it ;ppp

ok
here it comes 2 rc helis connected to each other and operated by one transmitter ;]
[youtube]KWnobua4cGQ[/youtube]

more info: http://robo.kawes.eu/picoo/ (http://robo.kawes.eu/picoo/)
ps: this time i compressed the imgs ;p
Title: Re: Building a Flying Robot
Post by: airman00 on February 04, 2008, 02:39:01 PM
no i mean a two bladed chopper like this
top view would look like this
O-O
So it would create a Chinook (http://www.enemyforces.com/helicopters/ch47_chinook_2.jpg)

exactly like a chinook!

any robot chinooks out there?

@Kawes  : thanks for the video!  Any idea  how to make it not spin the body so much , or maybe you can do three or four helicopters taped together , please?
Title: Re: Building a Flying Robot
Post by: KaweS on February 04, 2008, 02:48:34 PM
believe me that i'd love to, but i;m just not allowed to do sth like that ;p
my mgr was just off today. i didn't expect that so i hadn't too much time to figure out a nice connector for them.
next time i'll try to give you some more ;p
Title: Re: Building a Flying Robot
Post by: hgordon on February 04, 2008, 03:24:54 PM
Next time, use coaxial rotor heli's like the Blade CX2 and you won't have the issue of rotational torques.
Title: Re: Building a Flying Robot
Post by: KaweS on February 04, 2008, 03:58:30 PM
well... we do just one rc heli with coaxial rotor - Apache AH64 Longbow (http://www.modelzone.co.uk/rc_apache_ah64_longbow-details.htm)
the 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
Title: Re: Building a Flying Robot
Post by: airman00 on February 04, 2008, 06:07:31 PM
well... we do just one rc heli with coaxial rotor - Apache AH64 Longbow (http://www.modelzone.co.uk/rc_apache_ah64_longbow-details.htm)
the 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

OK cool!

Im thinking of having four helicopters attached together ( with the back rotors taken off) , maybe you can do that one day ...... ;)

Title: Re: Building a Flying Robot
Post by: KaweS on February 06, 2008, 04:15:54 PM
i just read that IR may have problems to recognize black colour - id doesn't see it!
does it always occur?
does it depend on quality of IR and it's readings?
can i adjust it somehow?
what about working in places with various brightness? let's say it flies from building outside.

i think i gonna need to use both IR and sonar to determine space availability...

and what about reading through rotors. is it possible with IR? do i need to place it on a boom or sth?
Title: Re: Building a Flying Robot
Post by: KaweS on February 11, 2008, 02:31:47 AM
last night a CAD a big my robot
i'll write something after work
just 2 pics for now:
(http://robo.kawes.eu/hss/overview_m.jpg) (http://robo.kawes.eu/hss/overview.jpg) (http://robo.kawes.eu/hss/radar_m.jpg) (http://robo.kawes.eu/hss/radar.jpg)
                 overview                                                  radar [on top and bottom]

what ya think about such a design? i forgot to attach legs [3 or 4]

PS: propellers are bent wrong direction - but it has to be just a general design to give you an idea of what i'm thinking of ;p
Title: Re: Building a Flying Robot
Post by: Tsukubadaisei on February 11, 2008, 05:17:03 AM
I am building some flying robots as well. http://www.societyofrobots.com/robotforum/index.php?topic=3197.0 (http://www.societyofrobots.com/robotforum/index.php?topic=3197.0)

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.
Title: Re: Building a Flying Robot
Post by: Trumpkin on February 11, 2008, 09:19:55 AM
you need a waaaaaaay bigger propeller on top to keep it up. 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.
Title: Re: Building a Flying Robot
Post by: gmatkins on February 11, 2008, 09:44:13 AM
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. I think this thing will fly.
Title: Re: Building a Flying Robot
Post by: Trumpkin on February 11, 2008, 09:49:14 AM
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?
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 11, 2008, 10:34:20 AM
Its an intriguing design indeed. 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.
Title: Re: Building a Flying Robot
Post by: Trumpkin on February 11, 2008, 12:41:25 PM
Quote
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.
that's pretty much what I said. ;D
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 11, 2008, 12:46:44 PM
I was just elaborating and building upon what you said...... and im cooler *Strikes a pose* :P
Title: Re: Building a Flying Robot
Post by: KaweS on February 11, 2008, 01:45:59 PM
cheers for those replies
to be honest i have no clue if it would fly - this is just an idea how it would look like. i've got another idea, but i'm too tired to CAD it today - maybe tomorrow.
for sure i don't want it to look like a helicopter - UFO-like thingy is what i want ;p

I am building some flying robots as well.
hope you'll help me ;ppp
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.
i don't know anything [yet] about aerodynamics and sure i'll google it first. if not - i'll have thousands of experiments for a good body ;p

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.
i think if one is slower than another, then it will turn, and that's what i want to use to operate it
Also the body is to fat and will catch wind to easily.
for sure i don't want it too big. i'm still not sure if i want to fly it outdoor. if so. it needs to be quite heavy to force the wind. if not - i want it as small and light as possible.

It looked to me like the propeller on the bottom is intended to counter-rotate to alleviate the need for a stabilizing rotor.
exactly - it's a kind of coaxial rotor ;p
And depending on the resources available the body is doable.
i think to make body of polystyrene - easy to adjust, with some kind of cage to make it a bit stronger - plastic perhaps.

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?
i'll paint eyes and mouth on it ;ppp hehehehe
well.... what's the difference for me? it's important for robot to know where is it's front ;p


i'm just surprised that no one said a word about the radar... i read a bit about them and i know that they're better than sonars in the air. but i couldn't find anything how could they work in small areas and at short distances...

for now i just keep on learning anything what is helpful to build a flying robot ;]

cheers,
Karol
Title: Re: Building a Flying Robot
Post by: skatj on February 16, 2008, 02:54:47 AM
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.

With two rotors, top and bottom, how do you intend to control the direction of flight? I'm not an expert on coaxial rotors, but I believe yaw can be controlled through differential torque of the rotors (doubt it would work on something like that though), but that won't matter unless you can pitch or roll the craft as well (can't tell which one it is for that design).

Don't try to come up with your own innovative design, especially if you don't know basic aerodynamics. Copy what others have done, you can't expect to pioneer anything with no experience.

A gps-only fixed wing aircraft designed around an inherently stable airframe, with a manual override pilot to take off and land is the cheapest, and easiest aerial robot to build.

Oh and, you won't be able to use a cheap accelerometer for something like this. You need a full-blown 6 axis IMU, especially since you want to design a completely new airframe that is incredibly unstable.
Title: Re: Building a Flying Robot
Post by: hgordon on February 16, 2008, 09:10:54 AM
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.

+1 what Skatj is saying

If you're serious about this, spend some time reading the threads on http://www.rcgroups.com/uav-unmanned-aerial-vehicles-238/ and http://www.rcgroups.com/vtols-360/
Title: Re: Building a Flying Robot
Post by: KaweS on February 17, 2008, 09:00:47 AM
it was just a proposition - i don't know how will it look like at the end, but certainly not like the first design - it's ugly ;ppp
second one is on it's way

how do i want to move?
first of all i don;t know yet if i gonna make variable pitch of blades - it will be more difficult and at the moment i don't know if it's worth effort
1. hovering
both rotors spin at the speed with opposite directions
2. moving up/down
adjusting pitch of blades
OR
adjusting speed of rotors
3. turning
one rotor spins faster and the other spins slower
4. moving forward/backward
and here i have problem ;p
general idea is to change pitch of one or both rotors, but i have no clue how it would behave - if i won't find anything i'll just test different solutions
what i'm thinking about is to tilt top rotor or both rotors that direction [it depends how fast the robot would turn] and then tilt the rotors to normal state.
i was thinking about a servo for each of rotors, to tilt them. you should already know - it can NOT change direction while is moving. but it's not problem at all - there's an other problem - keeping it balanced would be impossible or very difficult to achieve.
so i think i need to design a swashplate. it's difficult as well, but far less than previous solution... ok it was not a solution ;p

btw - what do you think about 2 motors connected parallel? does it have a sense?
(http://robo.kawes.eu/hss/full_m.png) (http://robo.kawes.eu/hss/full.png)  (http://robo.kawes.eu/hss/gears_m.png) (http://robo.kawes.eu/hss/gears.png)
[click to enlarge]
Title: Re: Building a Flying Robot
Post by: skatj on February 17, 2008, 03:35:50 PM
Again, what are you prepared to spend on this project? Even tried-and-true rotorcraft airframes that are relatively stable cost hundreds of dollars and extremely complex coding to balance. If you are deadset on going with rotors, at the very least go with a quadrotor or coaxial helicopter design, but I warn you even the most skilled of amateurs (read: non-military, non-industry) have not completely succeeded in building an autonomous helicopter. No offense, but what makes you think you can do it?

Variable pitch rotors are EXTREMELY difficult to fly, even for human pilots, let alone an autopilot.

I am telling you this because I too, once wanted to build a UAV, and I was just as naive and uninformed about it as you are. I had people who gave me a dash of cold water and put me on the right track, and if they didn't, then I would have ended up wasting hundreds of dollars.
Title: Re: Building a Flying Robot
Post by: KaweS on February 17, 2008, 05:04:15 PM
i am ready to spend £££ or even ££££ in years to design and then develop it. i am ready to spend thousands of hours for research.

what about complexity of coding? i really don't understand - how could it be so difficult? i guess what all i need is just to make it able to go any direction in 3D and if it drifts anywhere - go back.
ok - maybe i wrote it too easy. i know that i need to include present state of the rotors and even every single blade in it. i know that i need to stop before i achieve the destination, to stop exactly there, where i want to. and so on.

why did i choose a design with a rotor on each side? cause i found it the best solution to keep it small - coaxial needs a lot space between rotor discs - otherwise they will collide with each other. i know that would be MUCH easier - i could even use a ready mechanism from an rc heli. but it's not what i'm looking for.

and what make me think that i can? simplifying i think that i can make it, cause i think it's just up to me [and money] ;p it's extremely difficult and that makes me even more into it. as you know i'm not experienced. i am hungry to learn more and more about it. i believe that there is no impossible...
if i'll fail... well bad luck ;p but if i'll succeed... i'll be in kinda heaven ;]

as i guess you have a bit of knowledge. can you then help me? at least point me, where to look for or even what to look for.
what about money? i'm not a typical human - i don't like money... i'm dreaming about peace in the world and as long as there will be money there will not be peace. even if i'd put ££££ in it and then fail i wouldn't care about the money, but about failure itself.
Title: Re: Building a Flying Robot
Post by: HDL_CinC_Dragon on February 17, 2008, 07:23:17 PM
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. This isnt quite as easy as it sounds. Programming can be quite difficult for that sort of thing. Im too tired to get into detail as Ive been up for too long on too little sleep >_<

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.
Title: Re: Building a Flying Robot
Post by: KaweS on February 17, 2008, 08:16:35 PM
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.
as far as i know hi-end GPS receivers can pinpoint object to 2-5 meters [i need 1cm or so]
i though gyro/accelerometer would solve the problem [correct me please if i'm wrong]

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.....
for sure, but as i already told - that's not what i'm looking for

tired. must stop typing.
me too... g00d night and looking forward for few more words when you wake up ;]
Title: Re: Building a Flying Robot
Post by: izua on February 18, 2008, 12:30:40 PM
isn't a bee a pretty good flying robot? has tons of mAh-s, enormous torque and speed (think wings flappings per second) and is pretty smart :P just go get a bee and put it in a box :D
Title: Re: Building a Flying Robot
Post by: airman00 on February 18, 2008, 12:39:51 PM
OK guys, this thread is starting to get sorta off topic

the first thing  is first

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 way

After doing some research on the chinook helicopter I found that it works like this

Quote from: Wikipedia
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.[2]
(http://members.aol.com/alsgen/chinook.jpg)

It has two blades on top for lift and two jet engines pointing backwards for thrust forward

Maybe we should make two blades for thrust and two fans in back for thrust...what do you think?
Title: Re: Building a Flying Robot
Post by: KaweS on February 18, 2008, 03:55:49 PM
OK guys, this thread is starting to get sorta off topic
god bless you ;p

how will the darn thing hover autonomously?
Once we get that set straight , then we'll talk about GPS and sonar ,etc.
i wrote that before. for now we can skip starting the robot - i'll launch it from my hands at the beginning, till hovering and moving will be done.
once it's in the air, it'll make decisions based on sonars reading - if it drifts any direction, it will try to go back by calculating proper angel of rotor discs and the thrust. while it's moving [or trying] ;p it will still keep on calculate readings and include the previous ones. on that base it will decide to adjust angel and thrust.
that's why i ask for sensors - which will be the best for this purpose? sonar/radar/IR or any combination of them. i'll repeat once again, that GPS can pinpoint to metres - not centimetres, what makes it useless for me. if you know any better GPS devices - let me know please ;]

I propose three blades , but maybe there is a better way
After doing some research on the chinook helicopter I found that it works like this
Quote from: Wikipedia
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.[2]
It has two blades on top for lift and two jet engines pointing backwards for thrust forward
Maybe we should make two blades for thrust and two fans in back for thrust...what do you think?
Quote from: wikipedia
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.
the third is my favourite sentence ;]
but it's too big for me...
general idea of using 2 horizontal rotor discs to get as much thrust as i can get from 2 engines is still included. also i included idea of coaxial rotors. but it's still too big - they can NOT be to close to each other, because they will collide with each other when you'll tilt one [in real helicopters just the top rotor change pitch]
i want to keep it really small and that's why i've chosen such design. and i don't see a reason why it would be [far] less stable than normal coaxial helicopter.

so please - if you can help me - help me
stop saying that i will not do it cause it's too difficult...

cheers,
Karol
Title: Re: Building a Flying Robot
Post by: airman00 on February 18, 2008, 04:14:52 PM
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?
(http://www.aerospaceweb.org/aircraft/transport-m/v22/v22_01.jpg)

You can have a servo tilt the blades
Title: Re: Building a Flying Robot
Post by: KaweS on February 19, 2008, 02:42:59 AM
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!!!!
eee yeah i know. i didn't say i want to skip it. i meant i can skip start from the ground at the beginning till it will learn how to hover and then i'll go back to take off.

what about this design?
transverse rotors are like tandem - they take too much space ;[

You can have a servo tilt the blades
i thought about it as well, but in this case i'd need 2 servos for each rotor disc to tilt it any direction. it's much simpler than a swashplate, but drain more energy and much more room. still, i didn't refuse it.
Title: Re: Building a Flying Robot
Post by: Trikky2 on February 24, 2008, 05:45:39 AM
Hi there,

If you are interested in buying a kit of parts to start a fling robot how about something like :
http://www.asctec.de/main/index.php?id=15&pid=14&lang=en&cat=hobby

The people across at surveyor.com got one flying with the 'guts' from their SRV-1 controlling it and the camera working.

As for using the coanda effect, have a look at :
http://jlnlabs.online.fr/gfsuav/index.htm

All the best.

Richard
Title: Re: Building a Flying Robot
Post by: KaweS on February 25, 2008, 01:02:27 PM
i've already seen it, but thanks anyway
i didn;t know about coanda effect and i need to learn a bit about it as well ;p

cheers,
KaweS
Title: Re: Building a Flying Robot
Post by: paulstreats on February 25, 2008, 02:12:56 PM
I remember a demonstration of this effect is to place a small paper bowl upside and quickly waft your hand over the top of it. The bowl should lift up.

A paper bowl with a computer fan over the top of it might be a more promising demonstration, its all about passing air over the top of a curved surface. It creates a moment of low pressure, meaning that everything surrounding the low pressure area tries to fill it, so air from above below, left, right etc tries to fill the gap. In realism air from all the angles rushes into the area, but there is a drag towards the center of the low pressure. If there is an object there, this also gets dragged towards the area of low pressure, so the fan creates a low pressure area and the rest of the craft gets dragged towards that area (remember that every other direction gets dragged also). I pretty sure that this is how it works, but ive not heard mention of it for 4 years or so.

It might be interesting to see ideas using impellor type fans aswell
Title: Re: Building a Flying Robot
Post by: airman00 on August 27, 2008, 10:45:43 AM
Hey guys

guess what , I suggested my idea of a flying robot to the NYC robotics group I am a member of and they dig the idea! Looks like I'll be building this thing after all.
Title: Re: Building a Flying Robot
Post by: dunk on August 27, 2008, 06:45:02 PM
Quote
Looks like I'll be building this thing after all.
i'm actually making some progress in this direction too although i'm more interested in a fixed wing aircraft as it will be able to stay aloft much longer.

i'm working along the theory that i'll need to remember how to fly a RC aircraft my self before i'll be able to automate the task so i have been building my own RC system.
from there i'll be able to add autonomous functionality to the receiver module while still having the option of an override button on my transmitter module.

i'll be starting with a 2 channel glider because that's what i used to fly years ago. i've built a nice delta wing i think should fly ok...
i just this evening finished the firmware for the R/C system. test flight (or test crash...) later this week.

i'm fairly pleased with the R/C system.
no noticeable lag between moving control sticks on the PS2 controller and servo movement
i'll be documenting it soon so you'll be able to use it as a starting point if you want Airman. (ha! just realised how apt your UN is to this thread....)

if i had to design the R/C again though i'd definitely go with radio transceivers rather than the unidirectional RF modules i used.
having the ability to monitor sensor data from the plane while in flight would be useful.
anyone know any R/F transceivers that are good for over a mile range at low power draw?


dunk.

[Edit]
just answered my own question:
http://www.digi.com/products/wireless/point-multipoint/xbee-pro-series1-module.jsp (http://www.digi.com/products/wireless/point-multipoint/xbee-pro-series1-module.jsp)

next question: anyone used the XBee modules?
Title: Re: Building a Flying Robot
Post by: Terarius on August 28, 2008, 10:42:12 AM
Ive thinking about making a rc flying bot as well :P would be cool.

I cant really imagine a robotic flying robot based on sensors that controlls the motor/servos signals.
Cant see how that'll be sucessfull :P
Title: Re: Building a Flying Robot
Post by: Private Reid on August 29, 2008, 08:36:35 PM
I just finished installing Dragon NaturallySpeaking version 9  speech recognition software.

And I'm still trying it out so sorry for the mistakes.

But I'm thinking of making a robot airplane, I bought a mini rc airplane and found it could hold a lot of weight.  And I'm thinking the way to make it  a robot.thinking ill use a single IR sender and receiver attached to the nose of the aircraft. it was just a thought and of doubt it will ever come reality ( like Merce Mountain reports) "Like most of my other robots"  :D
Title: Re: Building a Flying Robot
Post by: roboki on September 30, 2008, 04:34:00 PM
When I read your long story of building this hovering, autonomous, 3dcPos tracking robot, I had to log in.
Although I'm fairly new to micro robotics, I have some background on aerodynamics, and anything related to flying objects, and experienced in R/C aircrafts.
I'll be honest and mean. It's not gonna work, and you'll fail miserably. Period.
People have been travelling with wheels for thousands of years, and it took another 300years after the first controllable vehicles came out that the wright Bros manage to stay in the air for 13seconds.
It's only been a century since the Flyer-1 took off, and it's only been last decade or so that we started seeing robotics even DARE to mix with aircrafts (by institutes who specialize in these things).
From my experience of watching what others(specialized in at least University level of aero studies) are capable of, it'll take another 5-6years before we start seeing some form of autonomous robots  hovering over our heads.
From what I hear (your CAD doesn't display for me), your robot is considered a micro~R/C-aircraft. That is, anything small enough to fit in your bag. Here comes my batch of reasonings as to why you should consider things beforer you even start this project:
Firstly, one of the major reasons why robotics couldn't mix with micro-aircrafts is due to source of power. Gravity is a mean thing. Just to keep your robot off ground, it takes tremendous amount of energy. Those R/C crafts you see have Battery life of at most 20minutes. This is done by specially designed batteries made specially for toy companies. (wowee uses a battery size of a bubble gum to power their dragonfly for about 8minutes). Even from annual R/C convs, most battery powered planes can't stay up more than 15minutes (that is, if the wind conditions are optimal), and that's why we have fuel combst engines. Considering that you want full electronic components and use direct thrust to gain lift AND hover, you need some NASA level of engineering to do all these things that you want it to do.
Secondly, using twin rotors sounds fancy, but to have all your 3 dimensional controls with pure thrust will require some 5mb big coding to sense and calculate your moves. This isn't like a wheeled bot where you're always on a stable leveled horizon and you move forward and backwards. You get constant fluctuations and dynamics in all your coordinates. ALL outdoor aircrafts require either extremely stable design, or sensitive sensing and sophisticated programs to keep their head up and stay balanced. Your controls will not work as simply as you think it would.
Right off back of my head, I can think of dozens of reasons as to why this will not work(GPS?/mapping radar for in a 3D situation?/Autonomous only works in static env where data programmed is all it needs, not in a always changing environment/mass(material)/where are u even tryin to get thrust for all this?/money???/how many hours will you spend...?/Many other "roflable" ideas. , but I don't think it's even worth it to fight over such minor post...

It seems like your dedicated, but sometimes you have to take your time and practice before your can jump over a wall.
However, I offer these tips in case you are really determined.
1) To Hovering problem, you can use whatever you want, just as long as your thrust is greator than your weight. This problem is rather easy... One propellar or twenty does not matter. Just like the vid of airplane hovering in mid air, if your bot's weight is heavier than radial drag your propellars create, you won't spin (good example would be drilling a hole on a wood-your body mass/innertia VS drag is too big that system will try to do least work by not "rotating" you). You can even have jet-engine for all I care. Theoretically, its the motor's power that determines take off weight, not the RPM or the Torque.
If you increase your torque, you reduce torque, and more speed, less strength. Yes, there is the optimal line because of the mass of the propellar and the minimal rad drag, but you can go with 25000 RPM small motor+3cm radial prop and achieve same thrust as to much powerful motor with less speed and more torque with bigger props (bigger doesn't mean better).
2)As to controlling in z(height) axis, I strongly suggest using speed of rotors. Pitch control requires high level of engineering. To have pitch control in such small robot packed with electronics is going to be extremely hard. If you want to use pitch control, you need lines of calculations as to shape of your prop and dynamics involved.
3)Turing- You said one can turn slower and one faster, but the problem involved with coaxial rotors, is that once your reduce speed on other rotor, you get difference in lift. This causes fluctuation in altitude. Helicoptors/VTOL like chinook and osprey use sophisticated level of programming to deal with this variance. if you are building a helicoptor, I suggest you get control for height and X/Y controls seperately. This means get vertial climb control seperately and turns/forward backwards seperately. However, if you MUST have it your way, use dividing thrust vectoring component under your "lift" rotor. In case of osprey(VTOL craft picture), it uses it's Ailerons to convert downwards thrusts' to sideways. You can use vector thrust like F-22 Raptor or ailerons, straws, or anything else that converts downwards thrust to sideways.
4)As to foward, I repeat Vertical control fluctuates and ur X/Y (forward and sideways) are not. Rule of the book is to have Vertical and Forward/turn seperated. You will find that Vertical thrust and maintaining that value will be much tougher than X/Y, as gravity only affects downwards. And if you get a sideways flux (like wind blowing from sideways), your bot will tild, creating diversion of your vertical thrust into sideways and some crazy movement (most cases, strong winds for R/C helicoptors result in "Impossible to control scenerio", where as in airplanes more stable). But if you really insist, then you can use diviersion of vec comp of lift thrust, as 3). Using some kind of rudder/elevator/aileron to shift winds coming downwards is easiest way if you choose to stick with your design.

Honestly, I feel like laughing at you, as to a fool who haven't built a 50$ bot to tackle such challenging project.
Seeing that you find the vid of acrobatic R/C plane amusing, you have a long way to go. Start small and get a R/C plane. Understand the physics involved. Starting at a NASA or University research level project is like skipping over the basics of skating, and going to the NHL, just cause you love hockey.
Hope I don't discourage you too much. Someday you'll be able to build your bot. Just that, that someday is not today...
Title: Re: Building a Flying Robot
Post by: nanovision on August 04, 2011, 12:59:00 PM
  Many people considered a telephone, light bulb, and even airplane impossible.  The wright brothers were told by academics with doctorial degrees in numbers not accurate this was so.  And for many people these things remained impossible.  Edison thrived in failure, as did Bell and the Wright Brothers but they took that failure public and without degrees in their respective areas of achievement accomplished the impossible.

  Perhaps you should visit diydrones.com (http://diydrones.com) where the impossible happens every day.  That is, that ordinary people learn to transform rc planes and helicopters or whatever into flying bots or skybots.  You could also visitbotmite.com (http://botmite.com) where I built a flying robot learning along the way.  However, I should point out that I code in more than a few languages and have more than a few years in electronics.  And, the point is one needs to start somewhere.  The biggest failure is not starting - especially such a wonderful learning experience as this.  As Edison is noted for saying "Rules, we have no rules.  We are trying to get something done here."

   Look at the economy, its a failure.  It was engineered to fail.  The fractional reserve system of the Federal Reserve Bank which is no more federal than Federal Express is making failure institutional.  But in some ways "the Fed" is a huge success and making the dollar, now a note signifying debt and only debt (as far as the Federal Reserve is concerned) - see how money is made - and transferring real wealth to a tiny group of a few people taking over political institutions and our lives. 

     
Title: Re: Building a Flying Robot
Post by: ofnature on August 05, 2011, 08:06:15 AM
Obviously he hasn't heard of the alphabet soup's (your fbi, cia,etc) flying insects..
Title: Re: Building a Flying Robot
Post by: NGuggemos on August 07, 2011, 11:36:57 AM
Wings are going to be pretty difficult for you to set up and make them function properly. You might just have to make something like a helicopter.