Patto

Either you love the looks of this plane or you hate it... I personally think it looks GREAT. Nitro Models has an ARF for sale of the Defiant, and I am really tempted to get it. Anyone out there have one?

The one thing I don't like about it is the lack of rudders. The fins clearly don't have any rudders on them, and the only yaw control would be on the ground... unless you take that little belly fin and hook it up to a servo... hmm... I don't think the scale plane had them either.

So, has anyone seen one of these in action?

http://www.nitroplanes.com/rutandefiant.html

AIVIA

My Feedback: (5)

P-Diddy,

I posted a thread back in late December on this airplane ... like you, I think the airplane looks neat and is very unique. Unfortunately, not many people seem to agree with us, or they are keeping quiet. Only 2 replies out of 231 views? I'm guessing no one has one yet. Here is the link to my post, in case you're interested:

http://www.rcuniverse.com/forum/m_51...tm.htm#5185753

Anyway, I've decided to build one and will document the build here on RCUniverse. I've always wanted a twin and I've always wanted a Long EZ ... so I will be getting the best of both worlds. Plus, I doubt anyone at my flying field will have one too, so it will be unique.

The full scale Defiant did not have rudders on the winglets. The Long EZ did and they are reported to be very sensitive, especially at low airspeed. For the Defiant, Burt Rutan decided to control yaw with a small rudder on the belly of the airplane (like a pelvic fin on a fish?), just under the forward canard. Nitro Planes does show this on their airplane, but it doesn't appear to be moveable when looking at the picture with the kit in exploded view. I intend to modify the airframe and make this controllable like the full size airplane. Essentially, I'm going to build a brass tube & rod affair very much like a water rudder assembly in an RC sailboat. This will be coupled to the same servo that drives the nosewheel steering.

Also, I intend to install a mechanical retract for the nose gear, like the full scale airplane. My biggest concern here is the available room, given the fuel tank location in the forward fuselage.

So ... what color are you going to choose? I like the fact they offer 3 different schemes. I'm going with the yellow, because it should be easier to see and I like the fact that it's $20 cheaper than the white!

Keep me posted ... and I will obviously post my progress here on RCUniverse.

BTW, I'm planning on a pair of Thunder Tiger Pro 46s with Slimline Pitts mufflers for power. I've been looking at the TwinSynch for controlling the motors as well ... looks like a great little unit!

Best Regards,
Scott

Patto

Hey, I encourage you to turn this into a build thread =)

I wondered if that belly fin was steerable. That would certainly be the way to go. The model looks like, in traditional Nitroplanes fashion, more of semi-scale or stand-off scale design. The horizontal stab looks too big compared to pics of the full-scale version, so I imagine that was to make it fly a little better than their prototype.

If I get one, and that's still an "IF", I'd put two Magnum .70's in it, since that is what I have on hand. I would definitely do the mod to make that nosewheel retractable, and I'd also mod it to make the fin moveable.

tomlee

My Feedback: (1)

I would assume the wing tube system is the same as the Cessna 337. Therefore, how would one hold the wings and canard on the airplane during flight?

In my case, with my 337, I will be using nuts and bolts as I found some plywood glued together to form blocks in both the wing panels and the center wing. The nuts and bolts would be installed about 3/8" in from the end of the wing tubes.

I too, am considering one of these airplanes. I have always liked the Velocity from Experimental Aircraft, but I felt the 1000 dollar start up was just too much.

Cheers, Tom

AIVIA

My Feedback: (5)

tomlee,

I'm anxious to see how the wings & canard attach as well. Based on the picture of the exploded view of the kit, it appears that aluminum tubes are used for the wings and canard. Maybe it's just me, but those tubes look pretty small in diameter, say 1/2 inch or so? Are they that small on the 337?

I've been watching the thread on the Nitro Plane 337 and it sounds like the assembly manual leaves a lot to be desired. I hope the assembly manual has a clear depiction, but if not, I'll have to figure it out.

I will be ordering my airplane on Monday, so I'll report back here once it arrives.

Scott

PS: I showed my wife the different color schemes to get her opinion. She says the yellow is ugly (to put it nicely) ... so I'll be ordering the white! [sm=72_72.gif]

tomlee

My Feedback: (1)

You are correct about the wing tube diameter. The replacements I ordered were 5/8. I have no worry about the dia, it is the tube socket with which I am having problems. One can always glue a dowel inside of the tubes for more strength.

When I tried to contact Nitro about the wing tube sockets, I received no answer from them. So, I went to TNT landing gear and pruchased the phenolic tubesockets with anodized tubes. THe nearest size is 5/8" One needs to hog out the tube socket holes in order for the new stuff to fit.

For me, if I order one, I will be prepared to replace the wing tubes and sockets.

I still don't know how the factory intends for the wings to be attached when one arrives at the field and needs to attach the wings. If someone finds out, let me know, I believe it is the same on both airplanes.

Patto

Like I said, I ended up epoxying the wings, tail booms, and center panel on my Nitromodels 337. That was simply because there was no explanation of how to do it in the manual and I did not want to risk attaching them with my own method that may not hold.

I'm sure the tubes will be plenty thick/strong enough. Just as long as there is some sort of wing retention explained, that would be nice!!

kwiatkma

OK I bought one, 6 months ago. I can't get the darn thing balanced, lets talk about this airplane...Some background...I'm building a real one so building the model seemed just to fit. I've been modeling for the last 17 years..so I'm no newbie. Now down to business. Has anyone flown this successfully yet? I can't get mine to fly right. First it was nose heavy then I rebalanced within the CG "range" which is 4.5 inches from the root of the main wing. And now it seems real tail heavy. I've crashed it two times already..no "flight" on it yet. I really am starting to think the CG measurement was mistranslated from Chinese......Anyone have better luck?

Patto

Have you contacted the folks at Nitroplanes about it yet? I'm wondering if they could give you the TRUE CG, instead of the one mis-translated from Chinese.

Seriously, they should pay someone, (like me!) a couple hundred bucks and give them each new plane that they get and have that person write an original ENGLISH instruction book!!

Let us all know how they treat you over there...

-Pat

kwiatkma

I'm working with Nitro planes right now...they sent me an email that stated in the fuel tank is in front of the CG balance with the tank empty and if the fuel tank is behind the cg point to balance the plane with it full....now the defiant has a tank in front and behind the cg (in line twin) so now what? I told them this and I haven't heard form them in a while...I've asked a question in their forum (which is on this board)

wils

I have just finished building a Rutan model. With the CG 4' behind the leading edge of the wing, it took 29 0zs. of weight to balance have not flown it yet. If anybody could give some info it would be greatly appreciated...Wil

neilh2

I just finished my Rutan Defiant and attempted to fly it.. Balanced at the required piont 4 inches back from the wing root. Started to do the take-off and before I pulled back on the stick , it lifted of and did a 180 inverted loop about four feet off the runway and crashed. It has way too much lift. and I didnt touch the elevator stick. Thinking the canard has too much lift. The canard is a lifting wing design. Could it possibly be required to mount the canard upside down? Is the CG differant from the instuctions? I haven seen any body say they have flown one sucessfully on RC Universe. Anybody got some info? I can repair the damage but If I fly it without changes , It wil loop and crash again.

corsair-wb

I picked one up a couple of weeks ago and I'm getting close to having it ready but the ugly white stuff ( snow ) fell this morning, so it might not fly till spring. I picked it up and then found this thread, I will be flying it even with the comments on this thread. I will tell all the results when it takes off. The sooner the better but with the snow here now it might hang around till spring.

Brad

neilh2

Brad, I understand that the CG in the manual is incorrect. It says 4.1 inches back from the front of the wing at the root. I have read on other tthreads that it should be 1.5 inches. Nitro model was no help

bps

My Feedback: (3)

Suggestion. Make a scale model of the model, say 1/4 scale. You can just use dupron, foamboard with the paper removed or some other material. Airfoil for this test not important, use a flat wing for ease of construction. Use this as a non powered glider to get an even slow glide using clay to adjust the cg. Once you have this then transfer the cg over to the powered model and you should be very close. This is how I test all of my non conventional designs. Do the math then test the scale model of the model. I think you will find the cg way forward of where it is now. Hope this helps

telejojo

mine lasted about 45 seconds, touch the elev. and it would go straight up,down and it would go straight down.it was uncontrollable.Dug into the ground about 8 inches in the middle of a huge fire ant bed.........I don't want another one.

kwiatkma

I have since given up on mine. It will turn into a hanger queen. I've taken the OS70 4 cycles and transferred them to other single engine aircraft. There is only ONE Defiant that I know of that is flying...You can see video of it on youtube. If you chose electric for your power you may be able to fly. If you chose gas like I did, I think the weight to wing loading, to CG can never be right.

This plane is going to hang from the ceiling in my hanger....I'm done crashing it!

Link to Youtube video:
http://www.youtube.com/watch?v=ytSXUadtQiA

http://www.youtube.com/watch?v=hZB2vmhvydA

corsair-wb

well this is no good, I'm not into the e-flying ( need the sound of gas ). But on the other hand the electric one is flying so the gas one shoud. Thanks for the vidios kwiatkma, and thanks for the other balance point neilh2.

I do have two TT 46 pros installed already and just have to put the tanks in and it will be ready to balance, becouse of the ugly white stuff that is now on the ground I do not think it will fly till spring. This will not be my first twin I had a nice little b-25 that had over 300 flights on it and I do miss the sound of twins flying.

telejojo

Good luck..................your going to need it.

Pilot Paul

HelloBrad and the other aspirant Defiant flyers, I completed mine some time ago, got up the courage and took it out, to say that they CofG is wrong is an understatement, mine did exactly what all the youtube videos showed and even what many are saying in this forum, the only difference is I managed to save mine and eventually get it back. I must tell you that it was the most exhilerating thing ever, I think my heart was beating at about 50000 beats a minute. Naturally and like many of you I have not flown it again as I want to be sure of the CofG before I take it out again. In fact perhaps my saving grace wa sthe fact that I have fitted 2 tanks to the front engine, I did this as the tanks supplied were in my opinion a little small for the OS 46 motors that I installed and at least of I ran out of fuel in the rear I would still have the front engine. I understand that the correct CofG is about 1.5 " from the leading edge, I will be trying this shortly and let you know. One thing I can tell you is that you must make 110% sure that the incedence between the canard and the main wing are correct, they must be the same so use a suitable incedence meter. Happy Flying Paul (South Africa)

Patto

I wonder if what they meant in the manual was that the CG was 4.5" behind the trailing edge of the FRONT wing/stab... that would be a lot closer than 4.5 behind the main wing... Or maybe 4.5" ahead of the LE of the main wing?

Ugh, I'm glad I didn't buy one now... although I still think they look cool...

Pilot Paul

Hi, well mine is ready again, I have fitted my AURORAradio so that I can have adjustments on all control surfaces, I have setup flaps as well, differential ailerons and separte throttle so that I can shut down one engine (idle or cut) if need be, I think to be honest that it would fly nicely on just the front engine. I have checked the CofG, it is currently 1.5" from the where the wing joins the fuselage, and this got me thinking, if you draw a line from the leading edge, the main portion before it racks forward it ends up at the +-4" mark, so I have some lead for the experiment and I will ensure that I have a good nights sleep so that I am relaxed and prepared. I saw that someone wants to use 2 x .70's, I was thinking of changing out my 46's for 25's as over powering this animal is not a good idea. My plan will be to take off at about 1/2 throttle and go from there, I noticed on the firstand only flight so far that when I reduced power it became more controlable- I will advise of the results on Monday (hopefully with pictures and the correct CofG location with a reference as to position)

Pilot Paul

Ok, so Iflew it again this past Saturday, seems that the small changes I made helped, the initial take off was perfect and at about 100ft it did its normal climbing and diving trick. Fortunately I had altitude and this was my saving grace. Ihave set exponetial on my elevator now (55%) as it appears the elevator is super sensitive and only the very smallest of movements is needed - I believe I am over controlling. As soon as I got my mind set and made very very tiny movements it flew well. The landing was an absolute greaser, I will take it our again this weekend, if anyone wants to know more drop me an email at [email protected] and I will reply. Happy Landings Paul

Pilot Paul

gpyles

My Feedback: (1)

Just bought a Yellow Defiant 74. Of course I heard all of the horror stories after I bought it.[X(] I concur with everyone else regarding the instructions. In a word C#@P. [:@] The CG position in the manual just seems wrong... Also with fuel tanks in the front and back you will have a shifting CG just from the slozhing. This is probably why the tanks are only the size of a thimble. Thinking about installing a single larger tank, but worried about the total distance to the motor. The main wing attchment seems iffy as far as the ability to remove the main wings and install them at the feild. Does anyone have experience with this?

I have heard the CG mentioned from 1/2" to 4" with the consensues being about 1-1 1/2" from the leading edge of the main wing where it meets the fuselage. Anymore insight on this?

As far as setting up the radio...

Setting up the main wings as flaperons?
What about the elevator? Is anyone setting this up as a "V-Tail" would that work?

twin Leo 40 glow engines
SpekTrum R7000 receiver
JR 11X transmitter