ARF UAV platform.

[pikeater]

Hi all,
I'm in a bind and was hoping you all might have some quick suggestions. Im a college student at an engineering school and over the winter myself and a roomate created a very simple gps-autopilot-camera-etc. system which we installed in a slightly modified Senior Telemaster arf. The plane flew great and i have nothing but praise for it but I'm trying to find a FASTER heavy-lift arf or easy to build kit to throw in the brains from the telemaster. I knew the the Senior was slow but WOW... I need a little more speed for a new project but would like to retain a certian degree of heavy-lift to support the brains and batteries. Also I'm stuck on dial-up for the summer and can't spend days searching through all of the planes out there. Any suggestions or links to faster heavies would be greatly appreciated. Thank You.
Wyatt Rivard

[kd7ost]

What is faster? I mean what speed range are you looking for? How dynamically stable does it have to be and do you have a budget? Electric, Glow or Gas?

Dan

[pikeater]

Dan, thanks for quick response. Ideally I'm hoping for a model with telemaster flying qualities; stable, decent rudder authority, good payload etc. but at least twice the speed. Realistically the Senior can't squeeze out much more than 20-30mph with any kind of wind so 40-50mph+ would great. We're currently running an electric axi/lipoly setup which provides lots of power and we would like to transfer that to new model if possible. Ultimatley I'm open to any suggestions electric or gas and I'd like to keep the cost economical(hopefuly below $500 or so). Thanks for the help.
Wyatt

[kd7ost]

I don't know if it will fit in your budget, and size wise its a little bigger, but the Sig Rascal 110 would fit your needs. It uses a great lifting but clean line eleptical wing and is a stable platform. I used to fly one with a Zenaoh G26 and it would hit 60 kph as per the GPS OSD information. An electric conversion of that plane would be sweet. I had about 5 pounds of gear in it. It is quite stable and easy to fly.

Dan

[kd7ost]

I should include that Sig has smaller versions of the Rascal too. I don't know of any other ARFs out there that fit the category, hit the price range and are low drag in the trainer category. Most are so draggy that no matter how much power you throw at them they don't speed up very much. The Rascal has some clean low drag lines in that wing.

Dan

http://www.sigmfg.com/cgi-bin/dpsmart.exe/MainMenuFV4.html?E+Sig

Or here. Comes in Red or Blue

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCXU0&P=7

[pikeater]

I should include that Sig has smaller versions of the Rascal too. I don't know of any other ARFs out there that fit the category, hit the price range and are low drag in the trainer category. Most are so draggy that no matter how much power you throw at them they don't speed up very much. The Rascal has some clean low drag lines in that wing.

Dan

http://www.sigmfg.com/cgi-bin/dpsmart.exe/MainMenuFV4.html?E+Sig

Or here. Comes in Red or Blue

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCXU0&P=7

Dan, thanks again for the answers. I had no idea they made such a huge rasacal. It's definitley alot cleaner than the Senior. As you mentioned above no matter how much power we add to the Senior it's still a barn door(don't get me wrong, it's an awesome great flying barn door). I think the rascal fits the bill and squeaks into our price range. I'd still be interested to see any other suggestions out there. Thanks.
Wyatt

[tritan]

A flying wing like the Queen Bee?

Tritan

[Tom Harper]

Pike,

If you want to go 60 mph, get a ST .90 on eBay.


To overcome the 'barn door' effect you will have to reduce the wing incidence relative to the horizontal stab or the thing will constantly climb. I suspect that you are reducing power to keep the model from climbing. Using down trim and down elevator will allow the speed to increase while suppressing the climb.

A Sr. Telemaster is rigged to be a floater. You can change the rigging of your present craft to increase cruise speed. First make sure you have the CG in the right place. Then start to raise the trailing edge of the wing. As you increase negative incidence the take off run will get longer and the model will get faster. The limit will be the prop speed not the airplane. The model will fly with the bottom of the wing significantly negative relative to the stab and line of flight.

The next thing I would do it toss the lifting stab. Use a flat plate or symmetrical section.

Speed is determined by your power source and prop. Parasitic and induced drag will limit the speed but at the 20-30 mph you describe I suspect that you are prop limited, not drag limited. What prop are you using? What RPM?

Before you change airplanes do the simple prop calculation. Assume the prop is 100% efficient. At the pitch and RPM available, is the prop capable of advancing the airplane at 60 mph?

[clolson]

I don't know if it will fit in your budget, and size wise its a little bigger, but the Sig Rascal 110 would fit your needs. It uses a great lifting but clean line eleptical wing and is a stable platform. I used to fly one with a Zenaoh G26 and it would hit 60 kph as per the GPS OSD information. An electric conversion of that plane would be sweet. I had about 5 pounds of gear in it. It is quite stable and easy to fly.


To affirm Dan's advice, the Rascal 110 is a really nice plane. We flew at least 5 lbs in ours and it handled it with ease. It has surprisingly clean lines. With an OS 1.60FX and an 18x10 prop, we could do about 85mph on the top end. In one down wind pass, the onboard gps clocked us at 102mph. Landings were a bit hot with that engine/prop combination though, so we switched to an 18x8 prop. That helped act as a bit of a brake when the engine was idling and slowed down the final approach speed, but also cut into our top end speed.

If I had to offer one nit-pick with the rascal it is that 90% of the easily accessible cabin area is *behind* the CG. That means you have to pay attention to where and how you are installing things to make sure you can get it all fit in and still maintain an acceptable CG.

The Rascal 110 is a really gentle floater because of it's light wing loading, but it's clean lines make it surprisingly fast if you put enough power up front. In addition, the designer used a pretty efficient sail plane derived airfoil for the eliptical wing, so it tends to glide for quite a while if you ever have an engine out. And on top of that, the designers at sig seem to really know what they are doing so the plane just really flies nice in all aspects, it's a great combination, and very elegant in the sky. It has enough aerobatic capabilities that it is not "boring" like the senior telemaster (not that the senior telemaster is boring, it's just fun in a different way.)

We had some logistical issues with the rascal, just because it is so big. I have to remove the main gear to wedge the fuselage in my Jetta (and I don't have room for any passengers when transporting the airplane.) The OS 1.60FX is a 2 person operation. It's big enough to require a two handed mongo starter, so you need a 2nd person to hold the airplane. Combine this with my helpers being students with no transportation, and the logistics of getting airplane and personel to the field for a test flight became difficult. We have a 2nd rascal (with the same G26 that Dan flew) and that is much easier to get started. But if you can afford an electric conversion, that is a great way to go. Quick to setup at the field, clean, quiet, etc. etc.

It's really hard to find anything substantial to complain about with the Rascal 110 ... just a really clean, capable, sweet flying aircraft.

Curt.

[rclinks2002]

What about maybe an electric glider of some sort? (anyone have any objections?)

Ben

[clolson]

My only comment on the electric glider option is that based on the airframes I've looked at, space will be extremely tight. Many airframes have barely enough room to wedge in the standard R/C equipment. That doesn't have to be a show stopper, but it was the big thing that jumped out at me.

[rclinks2002]

Does anyone know the Approx speed of the 8ft telemaster, using the axi 4120? (or other motors) Also estimated flight times?
Thanks
Ben

[clolson]

I have a Sr Telemaster with the Axi 4130 I believe. My speed numbers are just a ball park because I'm trying to factor out wind in my head, but I think you shouldn't expect too much more than something in the neighborhood of 35-40mph on the top end. If my math is right, I'm seeing something in the neighborhood of 60mph on the top end of my data, but I think's probably in a dive with a 15mph tail wind. I'm also seeing a lot of speeds in the low 15-25mph range. Assuming a 15mph head wind that puts the airplane in the 30-40 mph airspeed range.

So in a level cruise, figure around 30-35 mph, maybe 40-45 in a full thottle dive. If you back off and try to slow down, you can probably hold altitude at 15-20 mph.

Notice I'm using mph for my units, not kts ...

You'd get a telemaster because it is a big roomy stable gentle well behaved platform. You wouldn't get one to break any speed records. :-) The Kadet Sr. would be another pretty nice option in the same basic category. The Rascal 110 is bigger, cleaner, and much faster than either the Kadet or the Telemaster.

If you want my personal opinion, I would say that if you are doing basic autopilot development and just starting out, the Sr. Telemaster or the Kadet Sr. would both be excellent choices. If you need to go really small, there are a lot of different choices that have been addressed in other threads. The Rascal 110 is very attractive if you need to up the speed or the capacity over one of the Seniors. I see a lot of people doing the flying wings (zagi, unicorn, etc.) Those are small and robust and reasonably quick, but also pretty squirrely to fly.

So which airframe you pick, all depends on what you want to accomplish. There are lots of good ARF options if you are at the initial development stage. Someday if you want to build a UAV for some real world application, then you most likely will end up with a "purpose built" design to meet your specific mission requirements.

[pikeater]

Thanks to everyone for all the feedback. You've given me some great ideas, the wealth of info and comments was impressive. I think the Rascal 110 looks to be one of the best possibilities for replacement. I'll try to let you all know how it goes. Thanks again.
Wyatt

[DACeller]

Hi all,
I'm in a bind and was hoping you all might have some quick suggestions. Im a college student at an engineering school and over the winter myself and a roomate created a very simple gps-autopilot-camera-etc. system which we installed in a slightly modified Senior Telemaster arf. The plane flew great and i have nothing but praise for it but I'm trying to find a FASTER heavy-lift arf or easy to build kit to throw in the brains from the telemaster. I knew the the Senior was slow but WOW... I need a little more speed for a new project but would like to retain a certian degree of heavy-lift to support the brains and batteries. Also I'm stuck on dial-up for the summer and can't spend days searching through all of the planes out there. Any suggestions or links to faster heavies would be greatly appreciated. Thank You.
Wyatt Rivard

Would you care to share your "simple gps-autopilot-camera-etc. system" idea?

[rclinks2002]

DAceller,
I am working on the same project as pike, the simple GPs-autopilot-camera-etc. system consists of the RCAP V3 with Altitude hold, plus BTA Autopilot, with Digital still camera on a continuous timer, plus a telemetry transmitter/homing beacon. Then adding a long range (+5 miles) video camera. There are other particulars to the system that are advantageous to the desired mission here......

Ben

[minitelemaster]

[QUOTE]DAceller,
I am working on the same project as pike, the simple GPs-autopilot-camera-etc. system consists of the RCAP V3 with Altitude hold, plus BTA Autopilot, with Digital still camera on a continuous timer, plus a telemetry transmitter/homing beacon. Then adding a long range (+5 miles) video camera. There are other particulars to the system that are advantageous to the desired mission here......

That sounds awsome. I've been thinking of creating a similar system on the senior telemaster I'm building. Any advice on a "long range (+5 miles) video camera?" I've been flying by looking at an old television with my minitelemaster, but can't really get far away due to poor range with a cheap tx.

[rclinks2002]

The long range video is also a problem on this end. I am trying to use the black widow av stuff with 1 watt and high gain antennas. I havent had the time or a few other things to properly test the range. More to come later....

Ben

[JettPilot]

With a 1 Watt BWAV 2.4 GHZ transmitter and standard receiver with a 14 dBI patch antenna I get range of about 6 miles. The snow starts to get bad enough beyond 6 miles that it is hard to fly by the video.

JettPilot

[JackBauer]

I have a HAM license. Could you tell me what you've found out about the best ways to go for longer range? I don't know if it's amplifying your signal, using a special antenna, going to a radio modem (how does that interface with the receiver or servos?), possily using a cell phone and cell phone modem in the plane (?), using a better antenna on the plane, using the 50 or 53 Mhz frequencies that we can as HAMs -- or what. You say that you're flying six miles away and I understand how you are getting the video back but not how you're controlling the plane.

Thanks,

[minitelemaster]

[QUOTE]You say that you're flying six miles away and I understand how you are getting the video back but not how you're controlling the plane.

I have the same question. BTW, what is the typical range of an rc aircraft radio system, and do the new 2.4GHz systems have the same range as the 72MHz?

[minitelemaster]

Hey JettPilot, could you tell us your setup, you sound like you've got it all figured out!

Thanks