CARF Diablo 3D Jet

CARF Diablo 3D Jet

Designing a little brother to a very successful 3D-Jet icon is a challenge. 3D performance cannot be just copied to a smaller scale. Lots of aerodynamic details have to be considered, wing has to be enlarged, airfoils possibly to be changed, complexity has to be reduced since the smaller size won't require that much transportation gimmicks to break it down... Naturally wing loading gets higher, planes get faster, room for servos and engine gets more challenging. Now what if the smaller brother appears to be working even better than the big master? Well... then, a job has been truly well done. CARF-Models Diablo. The little brother of CARF-Models Mephisto. More diabolic? More demonic? We leave it to you to decide. Best try both...!

    

When it was presented the first time many several years ago, the Mephisto was deemed a 'controversial' design. True. The looks were very special. One thing was obvious: Form followed function. That's what ruled the design philosophy. Of course, it was supposed to do the very special things we envisioned, it couldn't be mainstream.

 

The Diablo has to satisfy even added performance requirements:

We wanted to make sure the shipping box size stays under 2m length, but wanted to eliminate the two-part fuselage. So, we opted for a large canopy hatch with the entire nose being removable. This generates a great access to all components in the airplane, be it electronics, fuel system or engine.

We wanted to be able to maintain the engine very easily, remove it from the airplane quickly. So we attached it to a carbon mount, which connects directly to the thrust tube. That way we can remove the engine/thrust tube assembly by taking out 4 bolts, and the best thing is, that adapter plates are included in the kit so that many different types and sizes of engine can be used without any drilling or fitting.

Even though the 3 piece wing of the Mephisto is a fantastic design feature for a large jet, it didn't make much sense with the smaller Diablo anymore. The plug-in wing design saves weight and minimizes complexity, it allows to attach also the flaps with an elastic hinge. Still the trademark style landing gear, retracting forward into the wing, has been kept. The airfoil and the wing shape has been matched for the different aerodynamic requirements of a smaller airplane. Increased cord length (width of wing) adds wing area, makes it less critical in slow flight and stall conditions. High Alpha hovering is incredibly easy to do. The stand on its gear got wider, too.

   

The tailerons of the Diablo are not limited by geometry in deflection anymore. Even if it's hard to rectify that its needed (it isn't...) but it 'could' travel more thn 45 degree up and down for the weirdest maneouvers to be still tried and tested.They are weight balanced ex factory and don't even need a fixing bolt anymore - they lock to the fuselage with a bajonet type mount. Needless to say that they also got increased area, without adding to the span.

The vector is one of the few items taken over from the Mephisto without a change. It is a simple, genious and light weight outside vector, which won't create any thrust loss.

   

 

   

Initially, we were hoping to get it to work great with a 250 N engine allowing smaller engine sizes if less 3D performance is required. Well, we managed a weight of 12.8 kg dry for the prototype, so it was clear that a 200-220 N engine would be totally sufficient. After our test flights with a Kingtech K210G4 we couldn't believe how much power reserve we had available, climbing out of a hover fully fueled with ease. The 4 l fuel tank on a 210N engine gives you 8 min flying time even with lots of hover practice you'll never feel limited in flying time. And the fuel tank is very close to the CG, so you won't feel any change of behaviour during a prolonged flight. Anything more than a 210/220 size engine is truly overkill and not recoommended at all.

    

    

Many have asked if the Diablo can also be flown with a regular non-vector pipe. Well, yes, we will offer an option for those as well. However, the diameter of the thrust tube will be smaller as it will be a dual walled pipe, which still needs to fit unter the taileron spar. No problems, as the engines should be limited to 140-160N in the non-vector application anyway. That will save another half kg or more, and the Diablo will become a real floater with still breathtaking aerobatic precision.

Putting the plane together at the field is now taking only a few minutes. Push on the plug-in wings, tighten 4 knurled nuts, put the gear down, lock in the tailerons with bajonet twist, and the ones with really small cars slide the fin on the dual carbon tubes and secure it with a single M4 bolt. That's it. Charge, fuel and fly. Speaking of small cars, the Diablo will fit in any small 'hatch back' or snug barely noticed between larger planes in your trailer. 8-10 l or 2 gal of fuel will give you 3-4 exciting flights after work - it's a daily flyer, so to say. No excuse for not going out to practice regularly. It will make you a better pilot fast. 

   

We start delivering the first Diablos in the blue/white/orange "Demon Scheme" but allow colour swaps as usual. More standard schemes will follow, but there's always the option to copy an existing Mephisto scheme at reasonable cost on the Diablo, too. 

The CARF-Models DIABLO is the next sensation. Lets see where the journey takes us...