Vimana89 Arrowhead Tailed Delta(Tried and Tested, Plans Released!)

[Vimana89]

overhauling to add pics and info of proptotype2/1.0.(the proper release model on the plans) a lot of current info here on page one is only about the first prototype, which had flaws in the air flow that lead to stalls

Prototype 1

I threw this together last night and this morning, for several reasons. I had some parts from a failed build around an radial 1806, and was getting burnt out/needing a break from super slender deltas, FTFC20 entries, and any kind of RET plane. I need to push forward with my aileron Kung Fu. I wanted something more along the lines of a more standard delta or fighter, that would be Nutball level easy to build, and extremely easy and forgiving to fly. This is about mighty mini size, with a 20" wing span by 24" wing chord and 30" or so overall length. After a rough maiden with a heavy battery and not ideal prop, I tried with 850 3s with 6x3x2 prop(a very standard setup for this size plane) and she flew outstanding! Not particularly aerobatic, but super smooth turns, awesome stability, and full stability, turn, and climb at low speed on half throttle. I'll get some video when I can get a new cheap action cam, which will be soon. This plane looks a bit crude now, but flies great, and can always be made neater in later versions.

UPDATE: flies just about as well with 850 5x3x3 as with 6x3x2, though the quality of the three blade props is flimsy. I added a small horizontal stabilizer or "Taillet", and got more used to flying ailerons. This plane not only handles well now, she handles exceptionally nice. The speed envelope is quite flexible, and with a little practice, this plane can easily be flown very slow or quite fast. This is no high alpha stunt plane, it won't do a big cobra or tail stand, but is capable of a little gentle high alpha for low and slow flying, and high alpha flares for landing. I will try to push the high alpha a bit more and see how much she can do, but it won't be anything extreme. For basic yanking and banking and smooth turns, I have not built or flown a better plane yet.

 

[Vimana89]

Design/Aerodynamics/Parts/Dimensions

Under work to reflect prototype 2/1.0 release. Prototype 1 dimensions and data have been removed, though references to it and its flaws(and how they were overcome in the next version) proudly remain throughout the thread for reference and learning.

 

[Vimana89]

Reserved for build guide

 

[Vimana89]

OLD PROTOTYPE(tailplane/stall issues)

First clip

With "Taillet"

Wind test 9 MPH+ with gusts

Prototype 2/1.0 successful

5x3x3 Early Compilation

 

[Vimana89]

Reserved

 

[kilroy07]

Looks kinda like a star destroyer....

 

[Vimana89]

Looks kinda like a star destroyer....

Yeah, a little bit. I didn't go too slender with this one but it's got some sweep to it, which helps a lot with stability without any dihedrals.

 

[Vimana89]

I'm really going to enjoy flying this one around for now, but I do have some potential upgrades planned for any future versions. I may add winglets and/or a "taillet", and either landing gear or at least a skid on the bottom to protect the wings and prop more on landing. I can always use lighter servos, do the wiring cleaner and through-wire the servo cables to the bottom spine, and even potentially add a nicer motor mount or even electronics bay. Any suggestions for improving the design are more than welcome. If it is a practical improvement I will likely implement it, but want to keep this plane very basic. I want the weight and complexity to stay down, no fancy fuselage or airfoil(scaled up versions could perhaps use KFM).

 

[Vimana89]

Added a bit of colored vinyl for orientation and aesthetics. 6x3 prop was beat up. Replaced with a 5x4.5 bullnose, which should still be excellent with the 850 battery(will test). My troubles were on an overloaded plane with 5x4 on 1600.

 

[Vimana89]

5x4.5x2 not so great, created a bit of torque issues on launch. It could have. Web pilot error. I switched to 5x3x3 to see how that works, and it performs much like the 6x3x2 but quieter and seems to run cooler. The brand of props in this size is just extra flimsy. You get what you pay for 😆. When I was out flying, I found my action cam out in the field! I had time to get some footage before work, will edit and share later.

 

[Vimana89]

First footage up! Bad camera angle, edited the best I could. Mostly slower cruising, will try more higher speed stuff another time.

 

[Vimana89]

Added this little horizontal stabilizer to the tail of the plane. Such an addition improved the handling of my first V Sliver prototype quite noticeably after the first maiden. This plane already handles pretty good, but I think this will make it even better.

 

[Vimana89]

Those small horizontal stabilizers really are like magic on deltas! Historically, full-on T-tail deltas have run into problems when their elevator was located on their horizontal stabilizer on top of the vertical stabilizer. With both my V Sliver and this one, they gain some benefit from the top horizontal stabilizer or "taillet" as I sometimes call it, but the elevator is still located in the main line of air flow, so no deep stalls at high AOA from losing air flow over it. My plane flew even better with this, just like the Sliver, and I have now learned to fly it even better, The speed envelope is even better and it can go even slower and be stable, but part of that is also my flying and learning how much control input is needed in what situation. More video coming soon. A little more flight testing and some input from the community, and I can have a very polished, clean wired and sturdy 1.0 to share a build guide of.

 

[Vimana89]

Also, closing the naming poll early. I gave it some though, and the small bit of participation I did have was leaning towards Arrowhead. Giving it some consideration, it really is a hands down winner, because it's not flashy, not gimmicky, and accurately describes the plane's shape better than anything else. It has just enough "cool" factor while not being over the top or pretentious, and hints at speed and stability, and simple, practical, handmade craftsmanship(this plane can easily and quickly be drawn up with a straight edge without even using plans or templates if one desires and knows the dimensions). So, as of now, this plane's official name is the Arrowhead!

 

[Vimana89]

Second vid up. She handles so nice with the "taillet" thingy. I am planning to clean and polish this design up a bit, perhaps with a partial box fuselage at the front extended slightly for better CG, and spine the rest of the way. Future versions will have servo cables through-wired along the spine along the underside of the wing rather than on top of the wing, and will look a bit cleaner. Other than that, I wasn't going to change much, except extend the elevator by a quarter inch, and possibly make the tail plane an inch wider in span, and perhaps then add a quarter inch to the ailerons to compensate.

 

[Grifflyer]

You've gotten a lot better at flying AET!! Good work

 

[Vimana89]

You've gotten a lot better at flying AET!! Good work

Thanks! I'll always have a couple RET fun flyers on hand, but I'm really liking the more scale, real time feel of ailerons. The turns are just so much smoother. This is more the direction I want to go in for more serious builds, like say a Saab Safari or something like that, or any Cold War jet. The arrowhead is definitely a great yank n' bank plane for just one sheet of foam. I feel a lot more confident building and flying AET since making this one.

 

[Vimana89]

Got some wind out. Nothing ridiculous as of now, but definitely noticeable, with some gusts here and there. charging batteries, then I will very likely do my first flight test of the Arrowhead with imperfect wind conditions, to see how the design hold up at the smaller scale with no airfoil. The size and weight work against it a bit, but the aspect ratio and thinness of the one sheet wing with spine instead of box fuselage, as well as lack of dihedrals, are favorable traits for wind resistance. I just need to not let a gust carry it away at slow speed at a high AOA like a kite.

 

[Vimana89]

Prototype flew fine in 9mph+ winds. Took a little getting used to, one stall and minor crash, no damage. Once I got used to it, it was not hard to keep the plane stable and going where I wanted it to. Slow flying becomes a bit sketchy, so higher throttle and speed are better for stability in the wind. some slower passes are possible, but when turning, a healthy amount of throttle is much more important to keep the wind from throwing it off. Video coming soon.

My next phase in this project will be to work out the 1.0 version, a cleaned up and perfected version of the prototype, same size and scale, no airfoil, but cleaner and nicer and polished up. After that, there's a good chance I will want to build this bigger, maybe a C pack and KFM air foil.

 

[Vimana89]

Wind resistance testing completed! Uncut clip showing last couple passes and landing in 9+MPH with gusts. Wind flight edit compilation coming soon.