New UAV airframe

[icebear]

I have been looking for a new small UAV airframe for my next project for a while. I tested the Mini Telemaster but found it to be too heavy (25-26 oz) for
its size (45" wingspan and 350 sq.in).

The bigger Telemasters would of course be better, but they just don't fit in my car and feel too big, so I have desperately been trying to find something in the 50-55" category with the followng qualities;

Wing area > 450 sq in
AUW < 48 oz (without autopilot)
Wingloading around 11-12 oz/sq.ft.
Roomy fueslage for components
Sufficient dihedral and ailerons
Reasonable semi-scale appearance

Finally, I stumbled across what seems to be a good candidate yesterday. A kit from Mountain Models called the Tyro 150 with these specifications;

Specifications:

* Wingspan: 54 in
* Length: 45.5 in
* Wing Area: 558 sq in
* Flying Weight: 37 to 45 oz
* Wing Loding: 9.5 to 11.6 oz/sq ft
* Controls: 4 (Rudder, Elevator, Ailerons (2 servos), Throttle)
* Power: 150 to 250 Watt Brushless Outrunner
* Battery: 3S LiPo (Capacity sized to chosen motor)

I am not a very experienced kit builder, but the laser cut kits from Mountain Models are very easy and joyful to build and that way I can make my modifications during the build.

I plan to have an onboard secondary GPS for recording of data and camera/video.

With an AXi outrunner and LiPO's I would be able to get the 30-45 min runtime on a 4200 mAh pack and have a range of 15 miles which is my goal.

/Icebear

[Connexxion]

Hi Bjorn,

I just encountered this on the internet:

http://www.kyosho.de/?page=shop/flypage&product_id=16041&category_id=5d5ed16d085d8380d832446c2d398191&mod_title=product#

[icebear]

Hi,

Thanks, looks nice!

A bit on the heavy side at 1600 grams, but I guess that could be fixed.
I'm actually looking forward to the kit build now, so I'll pass on the ARF's this time :)

/Bjorn

[wallaguest1]

should be a trainer?

Magister can upload up to 2,5 kg of weight, so you can add big batterys for long UAV travels, micro cameras, and video transmitters... with a 6600 mhz battery sure you can hold the plane 1 hour flying.

[icebear]

That would be a good candidate...
I've looked at the Magister but I felt that it would also be a bit big.
The Telemaster Electro is in the same category and have proved to be very good for lifting equipment and is stable enough. My issue was that I wanted a smaller Telemaster-type but the Mini TM was too small... :(
The Tyro looks like something just inbetween at 54" and would probably able to carry camera, gps, autopilot, extra LiPO capacity without affection performance too much.
Time will tell - it is on it's way according to USPS!

/Icebear

[tnavressdog]

Hey Icebear,

I used the Viking from Nesail for a UAV before. It can handle a lot of weight and is still floaty. The only thing I would improve is to make the fuse roomier but then again, I had a lot of equipment onboard. It could fit your requirement nicely. Even has a two piece wing if you're strapped for space.

http://www.nesail.com/detail.php?productID=3401

[icebear]

Thanks for the tip tnavressdog!

That's would be a perfect size too and it's even a bit lighter than the Tyro...

Since I've already ordered the Tyro kit, I'll try it out, but the Viking sure looks like great candidate if the Tyro isn't good enough - I like the name too ;)

If you could, it'd be intersting to hear what gear you used and if you have an pictures of your setup...

Thanks again,

Icebear

[dalbert02]

The Herr Cloud Ranger can lift a lot and is small. It builds fast. I can put in a Nikon 3700, a video Tx, a board camera, LED lights, and use 2100mAh 3S lipos. With a PJS 800, 11x6 prop, she can cruise for 1/2 hour and have plenty of thrust when you need it to get out of or into tight areas.
-dave

(pictured with an AXI motor, but that was changed to a PJS)

[wallaguest1]

icebear take a look to that one:
http://www.hhq.com.au/store/images//ii_11.jpeg
http://www.hhq.com.au/store/cart.php?target=product&product_id=361&category_id=66

1.1 meters and can hold up tp 1,5 kg !! it's glow but sure you can use a brushless :D
what do you think?

[icebear]

Thanks for the ideas guys!

I received the Tyro last night and actually decided to try the Viking laso (like the name! :)).

Great to see that there are more options...

I will post results when they are available - right now I have too few autopilots and too many planes...

/Icebear

[Airboatflyingshp]

Its a lot larger 75" but so simple search for a free plan of a model called Solonger its a dead simple build hugely stable vintage style machine that would suit this role perfectly. And it doesnt need a motor as big as shown.
Another oldtimer is the Hornet.

[icebear]

Thanks for all the ideas everyone!

I finally decided on the NSP Viking (and got the Tyro 150 kit too...!) and I got the ARF kit today. I actually had to carry it with me home from my business trip to the US since the freight was so expensive... I almost got caught in the customs with it too, but they let me through without having to pay $$$ in tax, duty etc... :D

First impressions are that it is a nicely built ARF, quite light and the wing looks HUGE even though it spans only 54 inches.

It was covered in non-transparent film and the tail has been re-designed since the pitures on the website.

The manual is very brief but I anticipate no problems in the build since most of the work is done. The wing has two bolts at the trailing egde and a funny way of holding down the leading egde using another two bolts.

Total empty weight excl equipment is approx 660 grams = 23 oz. - hard to see that you could make it fly at advertised 32 oz but I would guess 36 oz with a 2100 mAh pack and AXi 2808/24 motor.

I plan on 3 lb (48 oz) flying weight fully loaded with autopilot GPS, larger pack and camera. With a wing area of 4+ sq ft (600 sq in) that would give a mere 12 oz/sq ft of wingloading. A 4200 mAh pack should give me 40 min+ cruise time if my calculations are right.

I am hoping that the Viking will be a bit faster than my other Super Miss airframe, approx 30 mph cruise as opposed to 20 mph for the Miss.
The Miss can only fly in 15 mph winds absolute max before having trouble to track well. At 30 mph cruise I am anticipating 15 mph winds to be OK.

Here are some pictures before the build!

/Icebear

[icebear]

Its a lot larger 75" but so simple search for a free plan of a model called Solonger its a dead simple build hugely stable vintage style machine that would suit this role perfectly. And it doesnt need a motor as big as shown.
Another oldtimer is the Hornet.

Thank you for the plan ABFS! Looks like a really good candidate too!

/Icebear

[Airboatflyingshp]

Goodluck with the RTF Icebear, Hornet is a free download from the Plans Page.......... it has a very deep double decker fuselage and a mono wheel UC in original form and a huge wing area at 88" span and is a perfect electric candidate.

[Unterhausen]

Goodluck with the RTF Icebear, Hornet is a free download from the Plans Page.......... Where is the plans page?

[Airboatflyingshp]

http://www.rcgroups.com/forums/showthread.php?t=448080&pp=15 use this and its the first link.......... but go up a level............... BTW, the Hornet looks much nicer full size and is very light...........a good deep geared S600 will fly one I asked around some time ago.
There are other free plans links there but in searching for waterplanes plans I found hundreds of others that might suit you guys ncluding a nice simplified Skymaster great to convert to pusher power and camera forward set up.
A lot of old vintage designs will fly themselves virtually and carry huge payloads eg Radio Queen or Guff, Airwarden worth looking at if you want to build from a plan.

[icebear]

OK, so now the 'build' (it's an ARF after all) has started.

The NSP Viking is a well built and covered ARF and a very basic plane, which is what I was looking for.

The wing has a wide chord and looks BIG - over 600 sq.in. in a 55" wing...

The covering was tighth except for some bubbles that were easily shrunk back with an iron.

Everything weighs in at 660 grams = 23 oz.

I have added a small PJS 3D-1000 motor which gives max 1200 grams (42 oz) of static thrust - definitely enough for a crusizing UAV.

My weight budget;

Airframe + wing; 23 oz.
Motor; 3 oz
Radio/Servos/ESC; 4 oz
Picopilot + GPS; 2 oz.
Camera+PRISM; 5 oz.
Misc. 1 oz.
Kokam 3S-3200 8 oz
TOTAL 46 oz. which should give a wingload of 11-12 oz /sq ft

This gives about 80W/lb with the PJS consuming 250 W with a 9x6 prop.
I have calculated that the desired cruise speed @ 30 mph should be possible consuming 6A (65 watts) which should give me approx 30 min runtime on a 3200 mAh pack.

Flight tests without AP should be possible fairly soon...

/Icebear

[icebear]

The skies suddenly cleared up this afternoon so I got the chance to flight test the NSP Viking airframe.

The airframe balances perfectly with a 3S-3200 mAh pack up front so any smaller than that, it will be a bit tail heavy.

I noticed a small warp in one of the ailerons but decided it was to small to matter for the testflight.

It turns out the Viking is very nice and forgiving. Stalls are a non-event straight forward and the only thing I notcied is that I had to trim right aileron to compensate for the warp which was expected. Will have to sort that out with the iron later.

Landings were exceptionally slow so I can vouch for the 'touch-and-go' recommendation by NSP.

Now, it's just a matter of fitting some gear like camera, GPS etc etc etc... :D

Here are some in flight photos - courtesy of my wife!

/Icebear

[icebear]

I have done some more flight testing of the Viking (without AP) and yesterday I mounted my Garmin Geko 201 to get some rough flight data.

Top speed was around 60 mph = 95 kph (115 kph in a dive!)

Cruise speed around 30 mph on 55% throttle - this is 5-10 mph more than my other SuperMiss setup and excactly what I wanted.

I get about 20 minutes of mixed flight time on a new 3200 pack so I am guessing 30 minutes of 'cruise' time would be possible as planned on a 3200 pack.

The camera mount is now installed as well as the FS-8 rx + Co-pilot sensor. This is intended for aerial photography stabilization and can be turned off if I want the Picopilot to handle autonomous navigation and stabilization.

AUW is now up to 50 oz with camera (45 w/o), which gives a wingload of 12,2 oz/sq.ft with camera (no GPS) - not bad at all!

I will do some more flight testing before installing the Picopilot + GPS however.

/Icebear

[tnavressdog]

Hey Icebear,

I'm glad you like the plane and it seems it serves your purpose well. I missed this thread so sorry for the lack of reply. I don't have any completely loaded up photos of my Viking but the flight characteristics of mine seem exactly like yours. It can definitely fly fast if you want it to but will slow down for landings. Good luck with the flying!

[icebear]

Hi tnavressdog!

Thanks, I haven't forgotten who pointed me in the direction of the Viking! :)

I still have a small warp in the wing or tail to sort out because I have to trim right aileron to fly straight, but it flies really great. Tested it with the Co-pilot and camera today without any issues.

If you should find a picture of your (retired?) Viking, it would be fun to see.

/Icebear

[icebear]

Yesterday I installed the Co-pilot and the aluminium camera mount and managed a short AP sortie.

I set the co-pilot gain on ch 6 (lever) and about 50% gain is enough to keep a stable flight path while taking photos.

The Optio A20 is engaged by the gear switch (as intended later with autopilot engaged on the same channel) and the pictures seem OK even with power on. I need to adjust the camera angle with less tilt forward though...

/Icebear

[GeeW]

Neat mobile field box you've got there icebear :D :D
Good shots

Regards

Gordon

[John O'Sullivan]

Icebear:
in your photos the rear window of the Copilot appears to be shielded by GPS. Is this an issue?
john

[Connexxion]

Nice bird you have there.

Question: How did you mount the geko on the plane?

[icebear]

Neat mobile field box you've got there icebear

Thanks Gordon! Actually you'd be surprised how much you can load in that lower compartment of the 'field box' :D


in your photos the rear window of the Copilot appears to be shielded by GPS. Is this an issue?

John, I installed the Co-pilot 45 degrees turned (two sensor forward/backward), so when putting the Geko behind the sensor it does not obscure the rear windows much. I just use the Geko for flight testing, but it seems OK in that position during the first flights.

Connexion - I just used the crude method of strapping Velcro underneath the Geko. For saftety I even put a strip of electrical tape over it when flying. It is not meant to stay there for more than some test flights so I didn't bother to do it more permanent.

/Icebear

[speedy-biker]

may I ask where you bought that PJS motor?

Jacar

[icebear]

I got it from HAB in Swden - www.hab.se - but you can get it in the US also - I think Hobby-Lobby has them...

/Icebear

[tnavressdog]

Icebear,

These are a couple photos I could dig up of the Viking I was using. Enjoy!

[skymind]

tnavressdog & icebear, I notice in the last pic of yours tnavressdog that the wing - horizontal stab incidence is set at about zero relative to each other, something I tend to do.

[icebear]

Thanks for the pictures tnasressdog!
Great to see your Viking - really loaded with gear I can tell...
And you had the old colour scheme which I think looked better.
I did a short autopilot test this weekend but more to follow.

Skymind - I will have to check the incidence but it looks that way!

/Icebear

[icebear]

Today, I managed a 31 WP mission with the Viking after adding a mixer and removing the CO-pilot.

I am now down to 50 oz (w/o camera) which is just slightly over my goal at 48 oz.

Workshop introduced the OMNI Veetail mixer in his Telemaster Sr setup and I installed it to create coordinated turns by the Picopilot.

Since the Viking has big ailerons I decided to mix in ailerons with rudder instead of the reverse. This gives me some advantages;

- a normal rudder deflection gives just a small aileron input
- I can set the gain on the Picopilot higher (approx 50%) which I believe would improve its possibilities to track well
- The minimal mixed in aileron deflection (10% eg. 1/8" up and down) gives enough banking angle but is not very noticeable when steering on the ground

31 WP's done in 10 minutes which is a record for my 6 mile track - this should equate to approx 35 mph cruise speed

About 2/3 of the 3200 mAh pack was used up but that included 5 minutes of flying around also. Approx 1,5 mAh used up for the 6 mile route, e.g. 4 miles/Ah which is comparable to my SuperMiss setup.

Some more tweaking before I am totally happy but it is looking good so far!

/Icebear

[icebear]

Yesterday was more windy (about 12-15 mph) so it was a good day to test the Viking UAV.

The 31 WP testlap was flown in approx 15 minutes this time, 12 km's flown (8 miles) due to the wind causing somewhat longer route legs.
All WP's were made although some had to be rounded.
Max speed downwind; 42 mph
Min speed upwind; 20 mph
Average; 26 mph
2,4 Ah used up so that's also slightly more than the first test.

OBSERVATION;

I noticed that the Viking has a tendency to turn right sharper than left.
It also quickly looses more height in right turns - up to 30 feet during a sharp turn.
To fly straight and level I need a few mm's of right trim in the ailerons so I suspect this could be the reason.

SOLUTION;

I have decided to tame rudder throw down to 10 mm's (from 15 mm's) but leaving aileron mix as it is since it is very mild anyhow (approx 15% of normal throw).

I have also tried to introduce a little differential in the rudder, ie less right sufrace movement than left.

Any comments to this solution is welcome!

Finally, this is all part of the trimming procedure - I am very happy with the performance of the Viking/Picopilot combo so far!

Here are some pictures!

Enjoy!

/Icebear

[2bent]

Check out that huge warp in your right wing-- especially visible in the head-on landing shot. My eye shows the starboard wing at a far higher AOA than the left...

Hopefully that accounts for the trimming problem.

Cool plane anyhow!

[Rockeyes]

You could check that the wing is balanced if not done so already. Prop torque and wash can also play a part.
Hey just my two cents worth :)

[icebear]

Thanks 2bent & Rockeyes!

I have seen the warp and have tried to twist it back with with a covering iron but haven't been that successful. The good thing is that the plane flies very nicely with a little right trim and has no bad habits at all otherwise.

Balance the wing is also a good idea of course...

I'll try some more with the iron and go ahead with the rudder trims too see how that helps...

[icebear]

Finally, I have managed to get the NSP Viking dialled in. Mainly due to bad weather, it has taken some time, but otherwise it was a fairly quick process.

Thanks to the comments here, I also managed to straighten the wing to take out most of the trim needed for a straight flight path and this also cured the tendency to turn more right than left during autopilot navigation.

I used the Veetail OMNI mixer to mix in some aileron (15-20%) with the autopilot rudder commands). This has created really smooth coordinated turns. Since the mixed aileron is quite low (just a few mm's up/down), this is not noticeable when using rudder during take-off.

I tried to set quite low mechanical throws due to the big control surfaces and I still managed a fairly good gain setting on the Picopilot (around 50%).

See enclosed pictures of the tracking during the latest test.

Here's a quick summary of the setup;

NSP Viking 55" electric ARF
Wing area: 600 sq. in = 4,2 sq.ft
Motor; PJS-3D 1000 with APC-e 9x6 prop
JETI SPIN-33 ESC with 5,5v switching BEC (no need for separate BEC)
3S-3200 LiPO
Picopilot -NA + GPS
Veetail OMNI mixer
AUW is 50 oz excl. camera (55 oz with Pentax Optio)
Wingloading: 12 oz/sq.ft without cam or 13 oz/sq.ft with camera
Cruise @ 25 mph consuming roughly 6-7 amps = approx 70-80W, or 25W/lb
Runtime: 20-25 minutes on 3200 pack, approx 40 minutes on 3S-5350 EvoLite pack (not tested yet)
Range: 3.5 miles/Ah (5.5 km/Ah), approx 10 miles (16km) on a 3200 pack, approx 15 miles (25 km) on 5350 pack (not tested yet).

I am planning to test a more efficient motor - a german Torcman 280-15 which also goes more neatly inside the fuselage. Will be interesting to see if that could increase my range/runtime. I just have to find a nice shiny black spinner to with it also... :)

/Icebear

[Paul_BB]

Hi Ice bear,

I've been working on the HW/SW of my custom autopilot and I've just ordered my Scorpio Miss.
I am still on holiday so I have time to spend on my project.
I found a Miss for 69€ and I think it's cheap. :)

I have not bought the motor and controller yet and I would like to have your advice on the best motor/controller/battery for the Miss.
I will surely fit a camera on it so it will have to make with the extra weight.
Also: what kind of servos do you use on your own Miss ? Does it need mini servos (10g type) or would more conventional ones be OK ?

Thanks for the reply,

Paul

[icebear]

Hi Paul!

69Euro is definitely cheap!
I have the MEGA 16/25/4 inrunner and it is realy efficient motor with 250W...
On a 3S-2100 Lipo and 8x6 prop I get 20 min flights.
I would recommend at least 15g HS81 type servos since they will hold up better than the cheapo micro 10g ones. HS56HB from Hitech seem to be very good also and I think the only weigh 12 g or so (carbonite gears). Big heavy HS-300 ones would be a shame I think...
I like JETI controllers but that's just my preference :)!

Good luck and let us know more abou your project!
/Bjorn

[Paul_BB]

Hi Bjorn,

Thank's. :)
I'm afraid of inrunners because of the high rpms. But thanks for the power
specifications: I will buy a 200W outrunner of about 100g and also a
3S 2200 lipo. (Have you tried more than 2200 mAh for longer duration ?)
I will buy the Hitec 15g servos you talk about.

Here is my project I hope I will bring to completion:
Main project: have fun designing control laws for RC airplane.


1st part: heading control (WP) + GPS altitude hold
based on Bill Premerlany who designed ET301 GPS-UAV Development Platform.

HW:
- 1 Cubloc 280 (ATMega)
- GPS GlobalSat EM-406a
- Gyro 2 axis
- Accelerometer 3 axis

SW:
Navigation (input GPS - output commanded heading)
Lateral Control (input commanded heading - output elevator & rudder commands)
Vertical Control (input commanded altitude - output elevator command)

Problem:
- Capture Input with Cubloc is not accurate enough for 1ms - 2ms periods
so I will use little relays to switch from manual to auto control.
==> No semi-auto mode possible.

Later on I will maybe add a PIC controller just for this purpose: translate
RX signal to Cubloc.

- PWM is okay for servo control.

The advantage of Cubloc is the ease of programmation and it's cheap. I could
use a Motorola star 12 or equivalent but then I would need to spend money
on a C compiler and a programmer/emulator board. Debugging with Cubloc is so
easy. I want to play with control laws, not electronics.
I hope I have enough CPU power to compute controls every 20ms.
I have already finished extracting binary SiRF GPS message.

With the acc/gyro I will compute accurate heading and attitude using wash-out
algorithm. Roll is not a problem with Miss airplane's dihedral.

2nd part: add altimeter and pitot tube for auto take off & landing.

3nd part: add roll stabilization.

Pfew ! What an ambitious program !


Regards,
Paul

[icebear]

Very ambitious indeed Paul!

Outrunner of about 100g and 200-250W will be quite enough for that setup I think.
My MEGA inrunner spins an 8x6 prop so it has a rather low Kv for an inrunner.

So far I have only tested a 3S-3200 pack but I would go for the EVOLite packs - you can get a 5Ah pack that weighs about 11 oz!

Looking forward to hearing about your results!

/Bjorn

[Paul_BB]

Hello Bjorn,

I received my Miss airplane today. :) It's really ligth.
It does not have the Super Miss double dihedral wing but never mind.

The program "Drive Calculator" told me that the Axi 2814/20 Gold outrunner with a 10x5 APCE propeller should draw 4A of current at a supply voltage of 5.5V and develop around 6.5oz (200g) of thrust. The plane should fly at about 20mph.

The assumption of 6.5oz of thrust is maybe too optimistic. If not, then a 2S1P 4000mAh would allow the plane to fly 1 hour and thus cover 20 miles... :)
XPOWER's 2S1P 4000 Lipos weigth only 180g.

I will also buy two FS 501 BB servos.

That was for the good news. The bad news is that the microcontroller I chose does not manage interrupts accuratly enough. I may have to change it.

My vacations have ended so the project's pace has slowed down... :mad:
But my motivation is high.

Thanks for sharing your experience,

Paul

[icebear]

Hi,

I just added a video with the NSP Viking ARF UAV in the Electric Video section here;


http://www.rcgroups.com/forums/showthread.php?t=736866#post8104943



Paul - Great to hear you got the Miss. I am a bit curious about your motor setup. It seems a bit underpowered. Mine draws about 4-5A during cruise but I have 200-250W available druing take-off...

Anyway, good luck with the microcontroller...

/Bjorn

[Keith43221]

Hey Icebear,
I'd love to hear more about how the Viking has been working out for you.
Thanks.

[icebear]

Keith,

Thanks for asking! The Viking has been working great once I got everything trimmed out.

I did some minor mods to restrict aileron and rudder travel to be able to have a higher gain setting on the Picopilot.

The Viking now flies very well and tracks great. My only concern is range - on a 3S-3200 pack I normally get 20 minutes of flight @ 25 mph cruise. I would like to find a more efficient motor/prop/battery combo to extend duration to 30-45 minutes next season. Right now is 'building season' over here...

/Bjorn