Off-The-Shelf UAV Platform?

[qb7]

Hi All,

I know this kind of question was asked a while ago, but opposed to what was originally asked, my budget would quite a bit more than $500.

I have a bit of a project to work on, and need some solid advice. I will (hopefully) be building an UAV for surveillance and will be starting basically from scratch. (That is, apart from the base platform).

Although I would like to purchase an off the shelf system like the Dragonflyer Tango, I do not quite have that kind of budget to work with. I can source the navigation electronics, stabilization, camera equip, etc., but the basics is what I need first to get things off the ground (so to speak).

So far the requirements are:

1. The UAV would be required to fly controlled (with autonomous capability) for approximately 15km.
2. Fly out of line-of-sight.
3. Payload (Camera) of approx. 1.5-2 kilograms.
4. Electric power system preferably.

My question to start: What off-the-shelf fixed-wing platform should I consider?

I will certainly look forward to some experienced input.

[CenTexFlyer]

www.rpflightsystems.com

[lvspark]

I don' have an autopilot in my RPFS ShakerAP, but I do know the RPFS Wing can carry a decent payload with lots of room to spare, and is very stable. I hear they have an autopilot option that works very well.

[danstrider]

I've had terrific luck with the Telemaster series from Hobby-Lobby. Built three 8-footer versions and one 12-footer thus far. Typical mods are to strengthen the wing and make a trike instead of tail-dragger. The 6-foot version would be easy to electrify and probably carry in the range of payloads you're looking for.
http://art1.mae.ncsu.edu/twiki/bin/view/Main/8FootTelemaster

Dan

[qb7]

CenTexFlyer, Thanks for the link. It does look good, and will research it some more.

lvspark, I am taking a look at both the conventional and wing. Will have to do some more reading up on the pros & cons of both. I will search a link to RPFS ShakerAP. Thanks for the info.

Dan, great info; thanks. I definitely have my reading to do at the link you sent.

[lvspark]

I think Tower sells an electro telemaster RTF? Oh, here it is, hobby-lobby.. http://www.hobby-lobby.com/telemaster6.htm
BTW, the RPFS ShakerAP the same thing (older model?) as what centexflyer lionked to.

[qb7]

I think Tower sells an electro telemaster RTF? Oh, here it is, hobby-lobby.. http://www.hobby-lobby.com/telemaster6.htm
BTW, the RPFS ShakerAP the same thing (older model?) as what centexflyer lionked to.

Just noticed the same RPFS in both links! :)

[qb7]

lvspark. I am curious to know a little more about your RPFS ShakerAP. Could you tell me what all came with the platform when you purchased it? With your experience, how does the wing compare to a conventional platform? (eg. RPFS Slipstream II type?)

I am curious to know the pro's and con's. Maybe the wing is used for a different purpose opposed to the conventional platform?

[troynh]

Ivspark or CenTexFlyer,

Is Myron (http://www.rcgroups.com/forums/member.php?u=30009) the go to person for more info on the Shaker? Or Gene, are you the go to person? or both?

-Tim

[Myron]

Hey Tim,

Gene is doing alot of traveling right now and working with alot of "official types" in SoCal. I'm here at the home base trying to finish up the last of last years projects. I can tell you that we have been extremely busy and our web site is way behind our technology curve!..
The "Shaker" seen in the pics has been replaced with the "Spectra" and the "Talon" and the Slipstream has more or less been phased out.
The Spectra is a 54" two peice wing that breaks down and can be transported with all its support gear in one rifle case. The Talon is a 48" one piece wing that is carried in a larger custom case. The Talon weighs in at just a tic under 4LBS with a 10mp digital still camera and two CCD's with a live video feed. We have a mux that allows you to switch between the three cams while in flight. The Spectra is a bit heavier with the same camera gear and has alot more room for additional payload plus it has a hotter motor. Our focus right now is too keep the airframes flying weight under 4LBS because it looks as though the FAA is going to lighten up(pun intended) on the regs a little as long as your under that 4LB mark. Both aircraft can be configured for manual flight or full auto. If you have any more questions you can email me direct or call.

Myron
myron@rpflightsystems
512-731-3154

[Myron]

Here is a pic of each one. The blue one is the Talon and the white one is the Spectra. The new design of the center pod makes the aircraft more of a blended wing and body design.

Myron

[qb7]

Here is a pic of each one. The blue one is the Talon and the white one is the Spectra. The new design of the center pod makes the aircraft more of a blended wing and body design.

Myron


Hi Myron,

I took a look at your company website; very impressive equipment. In reading I understand you are phasing out the conventional Slipstream platform. Do you plan another conventional platform, or just going to stick with the Spectra and Talon wing platforms?

If you do indeed plan to stay with wing platforms, could you please provide some brief insight as to you decision, and pro's & con's of Conventional VS Wing platforms?

Thanks - Lachlan

[lvspark]

lvspark. I am curious to know a little more about your RPFS ShakerAP. Could you tell me what all came with the platform when you purchased it? With your experience, how does the wing compare to a conventional platform? (eg. RPFS Slipstream II type?)

I am curious to know the pro's and con's. Maybe the wing is used for a different purpose opposed to the conventional platform?

My wing came ARF form. Two wing halfs covered, with servos and linkage installed, a center section that had the motor and speed controller installed, a couple of wing joiners, nylon bolts, and the pod. I added rc rx, FMA co-pilot, prop, battery, and went flying. I use it mostly for video although it will carry a still camera now and then. My use for the wing over one of my other conventional planes is it is easy to transport, has good payload lifting, lots of room for payload, and does real well in windy conditions. Oh, yea, it is tough as nails. Bad landings in unimproved areas are no big deal. It is also fun to fly and pretty stable, does better than most wings I have owned during low speed manuvers. It does not tip stall and spiral. At least mine never has.. Looks like it has a thick, flat bottom wing and set-up more for lifting than speed or effeciency. I am guessing their new stuff addresses the effeciency as they claim to have same payload abilities with a smaller span, and longer flight times.

Drawback would be a simple autopilot has difficulties dealing with elevon control, and mine only last about 15-18 minutes on a 3C 2100 due to the more powerful motor. I am used to flying a SS or easy star that I have set-up for 30-45 minute flight times on a 3 cell 2100.

So ,in a nutshell, it's tough, light, stable and can transport a decent payload with ease.

Advantages over a conventional design? Hmmm, good question.. I'll leave that up to the aero engineers to answer :D

I'd love to get one of the new RPFS wings and vac bag it.

[alanhsu]

Hi All,

I know this kind of question was asked a while ago, but opposed to what was originally asked, my budget would quite a bit more than $500.

I have a bit of a project to work on, and need some solid advice. I will (hopefully) be building an UAV for surveillance and will be starting basically from scratch. (That is, apart from the base platform).

Although I would like to purchase an off the shelf system like the Dragonflyer Tango, I do not quite have that kind of budget to work with. I can source the navigation electronics, stabilization, camera equip, etc., but the basics is what I need first to get things off the ground (so to speak).

So far the requirements are:

1. The UAV would be required to fly controlled (with autonomous capability) for approximately 15km.
2. Fly out of line-of-sight.
3. Payload (Camera) of approx. 1.5-2 kilograms.
4. Electric power system preferably.

My question to start: What off-the-shelf fixed-wing platform should I consider?

I will certainly look forward to some experienced input.

I was more or less in the same situation as you.

1. 15km manual controlled range is a bit unrealistic. You'd have to use autopilot at that range.
2. fly out of line-of-sight can be done with autopilot, I use UNAV's picopilot. But you run some risk doing that (can't react to situations you can't see).
3. I currently run the soarstik platform which can carry 900grams of payload. Telemaster Sr. RTF is a fast and easy solution for your payload requirement (probably overkill). However, note that telemaster is not the best airplane to fly in windy condition.
4. You can run the telemaster sr. with electric power for sure, many has done it, lots of info on the net. E-power means low vibration, no mess. But you'd also run a higher cost and lower range (compared to gas engine). You also can't land and fuel, you need to land and charge, which is an much longer process^^.

So I suggest you look into telemaster sr. RTF. Lanier Husky 106 is another choice (its on sale at towers right now). If you can cut down your payload to 1kg, you can look into soarstik, even if you can't, you can still get a soarstik to test your autopilot since its cheaper to crash.

I would not suggest any type of delta wings (flying wings like zagi) for carrying a payload, since that's not what they are designed for. You need high lift airfoil for carrying weight.

[CenTexFlyer]

I would not suggest any type of delta wings (flying wings like zagi) for carrying a payload, since that's not what they are designed for. You need high lift airfoil for carrying weight.

I agreed with most of your post until this last uninformed comment. Unless of course you a speaking directly about a Zagi, which in that case, you are correct - it is not designed to carry a load.

However, a properly designed flying wing offers the most versatility between conventional and tail-less aircraft of it's class. A payload of 900 grams has historically been no problem for our Spectra class of flying wing. At least for the last two years or so, and things stand to improve dramatically in the near future. A few other notes:

Envelope : You can fly a wing in winds that would ground a Telemaster. While carrying the same weight.

Efficiency : We carry only two servos for control surfaces. Less to be damaged, less to affect (critically) flight performance.

Turnaround : Changing out (not charging) a battery would likely require less time and less margin for error than fueling a tank.

Autopilot : Granted, the U-Nav is not designed to fly a wing, but there are those out there that do just fine with a wing.

If you should wonder what I base this one, you can visit www.rpflightsystems.com and see what we have been working on for the past 7 years and what we have done with our wings. Just the facts, nothing "theorectical", actually used out in the field, proven to be tough.

Gene

[qb7]

Thanks for the information on your setup; much appreciate. That is basically what I am looking at starting off, and add my own components as need arises. I am not familiar with terminology; what do you mean by "...and vac bag it"?

My wing came ARF form. Two wing halfs covered, with servos and linkage installed, a center section that had the motor and speed controller installed, a couple of wing joiners, nylon bolts, and the pod. I added rc rx, FMA co-pilot, prop, battery, and went flying. I use it mostly for video although it will carry a still camera now and then. My use for the wing over one of my other conventional planes is it is easy to transport, has good payload lifting, lots of room for payload, and does real well in windy conditions. Oh, yea, it is tough as nails. Bad landings in unimproved areas are no big deal. It is also fun to fly and pretty stable, does better than most wings I have owned during low speed manuvers. It does not tip stall and spiral. At least mine never has.. Looks like it has a thick, flat bottom wing and set-up more for lifting than speed or effeciency. I am guessing their new stuff addresses the effeciency as they claim to have same payload abilities with a smaller span, and longer flight times.

Drawback would be a simple autopilot has difficulties dealing with elevon control, and mine only last about 15-18 minutes on a 3C 2100 due to the more powerful motor. I am used to flying a SS or easy star that I have set-up for 30-45 minute flight times on a 3 cell 2100.

So ,in a nutshell, it's tough, light, stable and can transport a decent payload with ease.

Advantages over a conventional design? Hmmm, good question.. I'll leave that up to the aero engineers to answer :D

I'd love to get one of the new RPFS wings and vac bag it.

[qb7]

Yes, manual control at 15K would be unrealistic. An autopilot is definitely in the plan. I previously read about UNAV's Picopilot and will have to take a look at that one again. I know there are others on the market and still have to narrow down which would work best with whatever platform I decide on.

I took a look that the Telemaster's and Soartik, but am looking more for a carbon fiber frame opposed to balsa. Also, kind of need the "cool factor" to provide a better impression for clients. It may sound silly, but I believe people are more use to seeing the sterotype UAV's for professional aerial AP. This stemming from military applications of course. The standard RC airplane platforms still give a toy impression even though we know they "function well" as professional AP platforms. In my case it is not just a matter of how the job gets down, but how it looks as the job is performed. Gotta listen to the client on this one!

I was more or less in the same situation as you.

1. 15km manual controlled range is a bit unrealistic. You'd have to use autopilot at that range.
2. fly out of line-of-sight can be done with autopilot, I use UNAV's picopilot. But you run some risk doing that (can't react to situations you can't see).
3. I currently run the soarstik platform which can carry 900grams of payload. Telemaster Sr. RTF is a fast and easy solution for your payload requirement (probably overkill). However, note that telemaster is not the best airplane to fly in windy condition.
4. You can run the telemaster sr. with electric power for sure, many has done it, lots of info on the net. E-power means low vibration, no mess. But you'd also run a higher cost and lower range (compared to gas engine). You also can't land and fuel, you need to land and charge, which is an much longer process^^.

So I suggest you look into telemaster sr. RTF. Lanier Husky 106 is another choice (its on sale at towers right now). If you can cut down your payload to 1kg, you can look into soarstik, even if you can't, you can still get a soarstik to test your autopilot since its cheaper to crash.

I would not suggest any type of delta wings (flying wings like zagi) for carrying a payload, since that's not what they are designed for. You need high lift airfoil for carrying weight.

[qb7]

Gene,

I have come across you forum name "CenTexFlyer" on more than a few forums. Now I know where you hang your hat! (Or should I say wings)

From a fixed-wing novice standpoint, I found through researching that the consensus places the wing platform as an all around better platform for combined stability and payload carry. Not necessarily from a military standpoint, but from the hobbyists and commercial vendors out there.

I agreed with most of your post until this last uninformed comment. Unless of course you a speaking directly about a Zagi, which in that case, you are correct - it is not designed to carry a load.

However, a properly designed flying wing offers the most versatility between conventional and tail-less aircraft of it's class. A payload of 900 grams has historically been no problem for our Spectra class of flying wing. At least for the last two years or so, and things stand to improve dramatically in the near future. A few other notes:

Envelope : You can fly a wing in winds that would ground a Telemaster. While carrying the same weight.

Efficiency : We carry only two servos for control surfaces. Less to be damaged, less to affect (critically) flight performance.

Turnaround : Changing out (not charging) a battery would likely require less time and less margin for error than fueling a tank.

Autopilot : Granted, the U-Nav is not designed to fly a wing, but there are those out there that do just fine with a wing.

If you should wonder what I base this one, you can visit www.rpflightsystems.com and see what we have been working on for the past 7 years and what we have done with our wings. Just the facts, nothing "theorectical", actually used out in the field, proven to be tough.

Gene

[CenTexFlyer]

Gene,

I have come across you forum name "CenTexFlyer" on more than a few forums. Now I know where you hang your hat! (Or should I say wings)


:D We've been hanging around flying our wings for a little while ;)

[alanhsu]

I agreed with most of your post until this last uninformed comment. Unless of course you a speaking directly about a Zagi, which in that case, you are correct - it is not designed to carry a load.

However, a properly designed flying wing offers the most versatility between conventional and tail-less aircraft of it's class. A payload of 900 grams has historically been no problem for our Spectra class of flying wing. At least for the last two years or so, and things stand to improve dramatically in the near future. A few other notes:

Envelope : You can fly a wing in winds that would ground a Telemaster. While carrying the same weight.

Efficiency : We carry only two servos for control surfaces. Less to be damaged, less to affect (critically) flight performance.

Turnaround : Changing out (not charging) a battery would likely require less time and less margin for error than fueling a tank.

Autopilot : Granted, the U-Nav is not designed to fly a wing, but there are those out there that do just fine with a wing.

If you should wonder what I base this one, you can visit www.rpflightsystems.com and see what we have been working on for the past 7 years and what we have done with our wings. Just the facts, nothing "theorectical", actually used out in the field, proven to be tough.

Gene

My bad, I was only speaking from my experience flying Zagi.
I would love to see your plane in person.

I think the biggest advantages of a delta wing over traditional design is that its tougher and easier to work with and launch.

But I still think delta wing platform is less suitable as a heavy payload carrying UAV. It simply isn't as stable and as efficient compared with traditional design. You can design the airfoil to carry weight, but you are limited to smaller prop size and shorter elevator moment arm. Smaller props are less efficient and shorter moment arm require the autopilot to work harder(more expensive)

Nevertheless, it is very suitable as a sub-1kg payload carrying platform. Very cheap and easy and crash resistant. Combined with FMA copilot, I think you might even be able to use picopilot instead of more expensive autopilot system.

[alanhsu]

I took a look that the Telemaster's and Soartik, but am looking more for a carbon fiber frame opposed to balsa. Also, kind of need the "cool factor" to provide a better impression for clients. It may sound silly, but I believe people are more use to seeing the sterotype UAV's for professional aerial AP. This stemming from military applications of course. The standard RC airplane platforms still give a toy impression even though we know they "function well" as professional AP platforms. In my case it is not just a matter of how the job gets down, but how it looks as the job is performed. Gotta listen to the client on this one!


Yup, cool factor is important if you need to handle clients.

If you are building this project for pratical application and do not need to think about clients like in my case, then balsa construction is actually better than the "cool" carbon fiber.

Balsa is as strong as carbon fiber at the same weight, but its a lot cheaper and easier to work with. Thus you can easily build your airplane perfectly (I am talking about flight performance, and crash resistance), while with CF, you can easily overbuild everything (meaning you lose flight performance, but gain crash resistance and durability). In layman's term, you are beefing it up, haha.

Crash resistance is a good thing if you will be crashing a lot, but it is completely unnecessary if you plan on just flying and not crashing at all.
With my project, I will be carrying expensive sensors, so I plan to have less than 1 crash for every few hundred flight, thus crash resistance is not a factor at all for me.

Just throwing out an idea for you to think about. Something half balsa half CF might be perfect for you.

[lvspark]

Thanks for the information on your setup; much appreciate. That is basically what I am looking at starting off, and add my own components as need arises. I am not familiar with terminology; what do you mean by "...and vac bag it"?

Very strong and Very light


http://www.pilotsguide.com/rc/vacbag.shtml

Added: Check around your area with some high end thermal flyers.. Thats where I saw my first bagging, and wow those bagged wings were sweet!

[kd7ost]

Crash resistance is a good thing if you will be crashing a lot, but it is completely unnecessary if you plan on just flying and not crashing at all.
With my project, I will be carrying expensive sensors, so I plan to have less than 1 crash for every few hundred flight, thus crash resistance is not a factor at all for me.



Hear hear. ;) Design to fly, not to crash. You will accomplish what you habitually work towards.

Dan

[lvspark]

But I still think delta wing platform is less suitable as a heavy payload carrying UAV. It simply isn't as stable and as efficient compared with traditional design. You can design the airfoil to carry weight, but you are limited to smaller prop size and shorter elevator moment arm. Smaller props are less efficient and shorter moment arm require the autopilot to work harder(more expensive)

Not so simple IMO, just personal preference. A wing can be stable and efficient. Conventional design for simple UAV is an easier task, but not for the reasons you state.

I'll go off topic a little since this is an older thread, and pose some possible advantages from my POV. With the shorter elevator moment pitch stability comes from specific airfoil design and smaller control surface throw. Roll stability comes from the sweep and acts like dihedral. Some flying wing designs are inherently very stable. That being said, servo and control arm linkage should be set-up so servo has full range of motion with small amounts of surface throw that results higher resolution of motion and less servo torque required for the control. (we all know a drone does not need to loop or roll like a zagi)
Advantage might be a smaller/lighter servo could be used, with higher precision, and less current draw on power supply? That advantage could be used to lower the weight of the aircraft to increase payload, or longer duration due to the reduced power consumption or weight?

There is no issue with prop size. Elevon position, length, or span can be designed around most any prop. Example.. 50% control surface on a 48" span wing would allow 24" for prop clearance. 12" elevons out on the tip would provide more than enough surface area for positive control.

The shorter moments do not make the auto pilot work harder, no rudder does. If a rudder was installed, any "normal" AP would do fine. The moment has nothing to do with it. It usually does take a more complex AP to handle the elevon control. I toyed with a simple AP on my wing and it did work. Not even close to perfect, but I did not spend much time fine tuning it either, I just wanted to see if it would work one afternoon, and it did.
(radio set for standard controls to Rc RX to a simple rudder throttle AP to an onboard elevon mixer to FMA copilot in elevon mode to servos)

Also consider that 99% of the flying wing/blended body creates lift where in conventional design, the fuse and other non-lifting parts create drag. Should be able to move the same payload the same distance, more efficiently, with a wing due to the difference lift vs drag.

“Boeing has conducted studies showing a BWB aircraft would be about 80 percent of the gross weight of a conventional aircraft designed to perform the same mission. The aerodynamic efficiency of the concept, uniformly distributing the lift over the total span of the aircraft including a lifting fuselage, requires about 30 percent less fuel to accomplish the mission,”
http://www.af.mil/shared/media/photodb/photos/060613-F-0000F-001.jpg
http://www.defenselink.mil/transformation/images/photos/2006-09/Hi-Rez/SCANEAGLE1.jpg

How about the best of both worlds??
http://www.flightglobal.com/assets/getAsset.aspx?ItemID=18778

Not dissin you or conventional aircraft design ( I am o.k. with both), just bringing it up for conversation.

[CenTexFlyer]

I couldn't have said it better meself, Mike! Thanks!

[kd7ost]

I too am not here to dis any design. Everything from conventional, to pusher, to pure wing and even rotor craft all have advantages as well as disadvantages over each other. It does us well to understand the pro’s and cons and decide for ourselves what design best fits our needs. People that put down one design over another simply lack the open minded approach to see the big picture.

A pure wing beats all the other designs for efficiency. The Horton brothers in Germany knew this as well as did Jack Northrop in designing his flying wing aircraft. The modern B2 bomber takes advantage of that as well as the inherent stealth capabilities. (A by product of the design that we usually don’t care too much about in our applications) Smaller props are fine in a flying wing. It’s because with the efficiency of the design you can fly with smaller power plants not having to overcome all the drag found in a conventional design. I have been flying a Great Planes slinger for over a year now and am astounded at the flight times I get with a small motor, prop and battery pack combination. With a little wind I can throttle way back and loiter, almost helicopter like with a little up elevator without losing altitude. Its very fun and a good learning experience. But there are two qualities in the design that I don’t like. One is simply interior space. With a small cargo there is no issue. But I really like the cavernous interior of a conventional design as I add, remove, change camera’s add fuel or what have you that makes the “loadmaster” task easy.

The other issue I have is a little more complex. I like Yaw. I do think the flying wing can be made to have Yaw but the airframe needs to be a little bigger and some unconventional things would need to be done. Something like putting a small airbrake on each tip that can be deployed on one side or the other to induce drag on that side and effectively yaw the plane. (This is only important to me in the type of AP I do. And may not be critical to most other folks) And despite any arguments to the contrary, the flying wing does not have the same inherent flight stability as a high wing conventional aircraft. You can look at the design, spend a few minutes with Newtons Laws and see that for yourself. Now I’m not at all arguing that as something that is bad or that can’t be worked with. As Mike has pointed out, setup is critical. But that’s the case with any UAV set up. (Depends on mission and quality of autonomous components of course) A UCAV is more radical than any manned fighter for example but that’s another story.

Now my favorite comment that I and others have been beat up over. A wing is pitch sensitive when compared to a conventional tailed aircraft. This is something we just can’t get around or argue with. The Wing is very short along the longitudinal axis. The direction of flight. Shoot a 6 inch arrow from a bow and track its flight. Shoot a 3 foot arrow from a bow and track its flight. Perfectly balanced and in a vacuum you may not detect much difference. But introduce a dynamic flight environment and see what happens. A little cross wind, some gusts in general, a tiny variation in control surface variation between one side or the other and the short flying contraption needs more subtle inputs to keep it straight. By the same token though, the short one can be brought back on line with very tiny adjustments. As the longer one veers off at a much slower rate, corrections to its flight path through control surfaces require more amplitude and or longer duration. They both will behave the same in the end but with different required correction capabilities. That’s why it is so important in a wing to keep the servo and linkage setup as smart as possible. Like Mike described above. Use a servo with good positioning capabilities. It’s best to use a servo with 5 pole or coreless motors for fine position response. Use a high torque rather than a high speed servo. High torque is plenty fast but slows down the response just a bit. It also takes less current to move because of additional gearing to get the job done. Set the radio and servo to get full motion during flight. Adjust the linkage to minimize the control throw and get that as close as possible first. Then make only small adjustments in your radio’s EPA to get full travel. Never set up a radical plane and use the radio to tone it down. That doesn’t take advantage of the servo qualities. You’re shooting yourself in the head. This setup concept applies to any airframe you use by the way. But it’s more critical in the flying wing. You want to fly smoothly using good stick resolution achieved from proper mechanical setup. This optimizes the design of your mechanics. It’s not hard to do in any design btw.

Many lower cost autonomous components don’t have the response or speed required to fly a flying wing without painstaking set up. It is harder to integrate because of the setup mentioned above and the fast response of the wing. Autonomous flight components are not anticipatory. They are reactive. The pilot can do both but by and large the pilot is anticipatory. Slow GPS refresh rates may have you flying zig zag patterns etc if your flight control setup is too extreme. Keep it toned down.

It can be done though and I stand by Gene and Myron and RPFlightsystems skill and experience. Also Mikes experience and reports. I have met Gene and Mike both in person and those guys know their business.

My own choice of airframes have to do with a variety of mission concepts. I need a cavernous fuselage. I need a big plane because I need to fly pretty high and safety through visibility is a must. Ease of setup and tolerance of minor variations is a must. The ability to land cross wind, (Stiff cross wind) is a must. Cross coupled ailerons and rudder provide the ability for that like nobodies business. I have to take off and land on rural roads and I have to deal with the unfavorable winds or I’m at a loss. My Pegasus design fits all those bills. Being a mid engine design it has a faster pitch rate than a tractor design. We rotate around the mass and mid airframe mass takes less effort. Not to mention it keeps the prop, fuel residue or what have you behind the electronics bay. (Yes I know, Electric has no residue) I’m not going to purchase what is needed to fly a 20 pound airplane and the ability to fly six hours within 7 hours of time frame in electric. That’s just too much un-needed cost in batteries, chargers, and batteries in my vehicle to keep up with during the off season. It becomes a loss with respect to cost effectiveness in the big picture. Gasoline works great. (Sorry, off topic a bit here)

The design Mike posted a link to above looks great. That’s the Integrator by Insitu. It is the best of both worlds. But by every stretch, it’s a conventional aircraft with a high lift wing. It retains ailerons, elevator and rudders while still keeping in a large fuselage.

A wonderful flying wing design is also made by the Insitu folks out of Oregon. The Scan Eagle. Take a look at their site and view the flying wing with massive cargo space.

http://www.insitu.com/

Anyhow, its just not as easy as asking what is best. (I know that wasn’t a question) But there is a lot to consider. And I do design, build and fly electrics too.

Maybe the best thing to do to start with is just to stick with something you are familiar with and that you have confidence you can succeed with. Examine your experience, your skill sets and what you think you can best accomplish to start with. As you move along you will learn new things that help you decide a direction. All of us have been through a growth and prototype process. It is probably quite rare to have your prototype design also be your final design.

I too am just throwing this out for discussion.

Dan

[lvspark]

Good info..

I agree flying wing does not save the SAME inherent flight stability of conv but it does have inherent flight stability. A few years ago I met these zingwing guys at a show and bought a few of thier wings. Awesome little flyers.. The kids loved em' and so did I, so simple and so stable.
I would suggest everybody try a few! http://zingwing.com/
http://www.youtube.com/watch?v=hmLAttm_2xI
http://www.youtube.com/watch?v=WpOSQTL73CQ

[rc34074]

kd7ost- where do the planes you show come from? do you build them? or buy them?

I'm referring to the Pegausu and Dragonfly?

Please post links to their source. thanks

Ed

[Unterhausen]

kd7ost- where do the planes you show come from? do you build them? or buy them?

I'm referring to the Pegausu and Dragonfly?

Please post links to their source. thanks

Ed
Ed, he builds them. He's got a couple of build threads either here or in AP. I'd look at the threads that he has started.

[qb7]

Ivspark and Kd7ost....very good information and definately eyeopening! I am just getting back from a lengthy work trip. I am so glad you guys chimed in; you both provided a lot of "food for thought" on how I can approach. I actually have across you (kd7ost) on RC-cam I believe, and you certainly know your AP setups!

rc34074...just the question I was going to ask. Unterhausen...thanks for answering! :)

[rpage53]

There a number of critical items missing from your mission profile. Real time surveillance at 15 km will require high altitude flight and powerful radio downlink, in which case you could maintain manual control. It would also require a substantial payload capability.

If all you want to do is fly to a location and take a picture with a hobby grade camera, you could do that even with a Zagi. Mission success might be low. There are thousands of dollars separating the 2 options.

I worked on a similar project 20 years ago and we were required to file flight plans and operate similar to other general aviation aircraft in Canada. I don't want to open the "legality" debate here, just want you to be aware of the complexities of what you are proposing.

Good luck,
Rick.

[qb7]

Hi Rick,

Well, it looks like I will now change what missions spec I am pursing. I think the complexities of what I was trying to pursue would definitely be beyond my knowledge and capability, and would take quite a ramp time to accomplish. So, I would like to try and stick with something that may be less complex overall. By the way, I am fortunately not constrained to any aviation rules or legalities where I currently live in SE Asia, including what RF equipment I would use. However, I will still fall in line with a safe operating rule of thumb.

Basically, the requirements now are:
1. Short runway take off or hand launch.
2. Perform horizontal 1 to 5 kilometer line-of-sight circle around my position. Max may actually be around 2K.
3. Elevation would be contingent upon what camera I could use to reasonably identify an object on the ground.
4. Electric power system.
5. Bling factor.

Guys, is there any kit on the market that comes close the kd7ost's Pegasus frame? I have seen a similar few before somewhere, but do not know if they were kits or built from scratch like kd7ost.

I think it would be best to build from a kit as opposed to ARF so I can learn a little more about how it ticks. I built my heli AP systems from bits and pieces, so I an not totally unfamiliar with model tickering. However, I will assume RC airplanes will be a different ballgame. From there I can add on components as my confidence and skill set increases.

[rpage53]

I currently live in SE Asia
Well that does make many things easier. Its hard to avoid the Feds around Ottawa :)

If you want to build it all yourself, I'd plan a multi-step approach. Choose an airframe and fly it to sort out the plane, power plant, duration and payload. It can take quite a while to fly 2 km perform the mission and return. You don't want to risk a few thousand dollars of electronics sorting out the bugs.

Look at the other builds in the forums and see what appeals to you. There are tons of choices.

Rick.

[qb7]

Yes, that was my train of thought. I would like to just start with the airframe and basic power system. Play with that for awhile, learn, then modify the power system and dynamics for what you stated; duration, payload, and other requirements. I had best get up off my ass and start looking at builds on the forum. Hopefully I can find something similar to the Pegasus. Thanks again.

Lachlan

[kd7ost]

kd7ost- where do the planes you show come from? do you build them? or buy them?

I'm referring to the Pegausu and Dragonfly?

Please post links to their source. thanks

Ed

Hi Ed,

I couldn't find any sources for a ready made or kit airframe that met my criteria with the Pegasus design. I did dig up a few builders and told them a market was available depending on what they came up with. The problem is that to get an affordable airframe you need mass production and sales. Both builders I found did a poor job with the build, didn't follow my design and size requirements, and wanted a lot of money for a substandard aircraft. So I ended up designing and scratch building my own. Sometimes that's the best way to go.

Anyway, I never did a build thread on the Pegasus but I tried to add pictures later due to high interest. That thread can be found here.

http://www.rcgroups.com/forums/showthread.php?t=792387

I really appreciated all the comments I got from guys on that thread. John O'Sullivan, who I only know through RCGroups had some comments that underscore the Pegasus design very well. It's Un-cool and purpose designed with no frills. The Pegasus is incredibly easy to fly. This is the kind of plane you can train new pilots on because it just about flies itself. The plane has logged well over 2,000 miles (3,200 km) while being flown from rural roads for its designed Ag mission. The plane and design worked out better than I had planned. It was only meant to be a prototype but I have a hard time thinking of replacing it.

The Dragonfly is a plane that I did an extensive build thread on. It was to meet a different flight criteria. This plane also flies itself but doesn't serve in the Ag missions. I use it more for fun shoots in the high dessert out where I live. Looking for Wagon swales, old structures and etc. I have a lot of fun with that. Anyway, that build thread can be found here.

http://www.rcgroups.com/forums/showthread.php?t=573747

Dan

[kd7ost]

For the record, I have been working, (very slowly due to work requirements) with Jimmy Prouty of VectorP fame.

http://www.vectorp.com/

Jimmy is a class builder with a high level of understanding about UAV's and Airframes. And my favorite part, system integration. Jimmy makes incredibly professional and sleek glass parts but it doesn't stop there. He designs, flies, and sets his planes up like I do. I think this will be a good partnership as we get underway and move along.

The goal is to build a twin boom pusher that is smaller than the Pegasus. It would be in the .60 to .90 engine to Axi 4130 electric size range. My plan is to fly Ag flights with it using the BME modified .90 super tiger gas engine. I know lots of guys prefer electric though so the power plant choice will be optional. I lean towards a preference to gas power in my heavy use working planes.

http://www.bmeengine.com/html/point90.htm

The project is near the surface but we both have other projects that are being worked on that need to get finished first. I had planned on just making a ready to fly plane for the people out there that have contacted me from the Agriculture world that want a Pegasus type plane ready to fly. (Lots of money but no builders) It seems like this plane design is so popular though that he and I should consider having a kit available as well.

This may not be a real fast project though. I have very busy summers and have a design underway that I've been contracted to build. I have to stay focused on that until I can deliver it.

Thanks for all the interest guys. We'll post information on that if and when it becomes available.

Dan