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Sunday, March 4, 2012

E-Flight UMX Gee Bee R2 BNF withOUT AS3X - Flight Review

Horizon Hobby makes it clear that their little Gee Bee would not have been possible without AS3X. But they also claimed that flying an Ultra Micro with AS3X "is like flying an expertly tuned giant scale model."  What an outlandish lie that turned out to be.

Even the original UMX Beast arguably has better aerodynamic feel than the relatively numb and significantly heavier Beast 3D.  AS3X can certainly help in certain circumstances, see my review for more, but to wildly claim it turns flying a toy micro plane into a giant scale expertly tuned model??  What the *^$%?????

I quickly demonstrated that even a small parkflyer equipped with a less expensive, near competition quality gyro system easily beats AS3X in raw capability, feel, tune-ability and of course aircraft transferability.  Although both my Z83X Cessna Aerobat and Z83X Pitts Special are much better overall performers than the size-and-weight-handicapped micro Beast 3D, none of these planes even feel remotely similar to flying a giant scale model as Horizon brazenly fibs.

So now when Horizon makes a bold claim, like their nifty little UMX Gee Bee would have been impossible to do before AS3X, I want to know if they are lying.  They left AS3X undocumented and impossible to turn off, but they forgot about one thing:

(Left) UMX Gee Bee AS3X board.  
(Right) UMX Beast non-AS3X replacement.
The non-AS3X board installs as a drop-in replacement.


I flew the non-AS3X Gee Bee today, video upload to follow.

BLUF:  I thought it flew a little better without AS3X.

General observations:

The ESC on the non-AS3X board was overwhelmed with OCP for the first 60% of the battery instead of the first 10%, so we know that Horizon did do an upgrade and simply botched their new ESC module.  I propped down to a 5x2.75 which helped, but surprisingly is still too strong for full static installed thrust.

This proves the ESC was substantially upgraded, but not enough, and that Horizon Hobby absolutely knew about the Gee Bee's OCP manufacturing defect before the plane hit the store shelves.  E-flite intentionally released a defective product -- zero doubt about that now.  This company is quite simply, chronically unethical. 

Observations about (no) AS3X performance, in no particular order:

Having AS3X engaged or not engaged is not a whole lot different--the AS3X to non-AS3X variants are even more similar than the Beast.  The Beast is an aerobat where AS3X can play a larger role in harriers and hovers and whatnot.  In a stable racer and there isn't much reason for a gyro add-on. The Gee Bee with AS3X variant is probably better for beginners given the Gee Bees slow speed, right rudder authority limitations, but overall adding AS3X results in a less gratifying flying experience for intermediates and higher.  I rated the UMX Gee Bee skills demand at 4/10, so beginners should think twice regardless.

The Gee Bee AS3X unit clearly de-tunes elevator rates, adds some expo and permits less travel.  To a slightly lesser extent, it de-tunes aileron travel and probably sneaks-in some expo.  Without the board, a computer radio can easily replicate the same de-tuning, or you can accomplish roughly the same thing by moving the plane's pushrods farther out on the control surface horns.

With that accomplished, I launched the little uncomputerized Gee Bee into Unholy oblivion.  Right?  No.  Not so fast.

With surface movement rates re-calibrated, the plane is one of the more stable ultra micros.  Elevator is not pitchy in the slightest, which surprised me, much like the GPGBR1 surprised me with its similarly solid, well measured elevator control.  Aileron control is equally solid, and without AS3X waggling it like crazy upon discovery of each and every node of structural resonance.   Rudder control remains aerodynamically deficient in the high demand corners of the flight control envelope.

The non-AS3X Gee Bee didn't fall apart in flight or explode in flames. In fact, it felt better connected and it is significantly more maneuverable in pitch and a little more so in roll, without AS3X engaged.

 The yaw axis feels exactly the same to me, as control is probably limited by the size and shape of the rudder itself and aerodynamic blanking from the fuselage when slow.  Like most planes, the Gee Bees requires a right rudder blend as you slow down and power up.

AS3X clearly dampens some of that rotation initially, but it also causes a more immediate control-loss once the gyro runs out of authority and the plane pinwheels left due to aerodynamic rudder blanking.  The airplane turns over a more connected feeling when you manually approach the right rudder stop with the control stick, and that way you know what is about to happen and can speed up a little or add some bank angle to counter rapidly diminishing slow speed rudder effectiveness.

The Gee Bee flies wonderfully uncoupled on knife edge both with and without AS3X.   Without it, the Sportster demands a touch of nose down elevator to knife edge arrow-straight and very stable.  Even with the reduced power available the plane can sustain knife edge flight, but you have to be careful not to trip the OCP or it gets pretty quiet 'til you recycle the throttle.  That is not an aerodynamic problem, it results from an overly cheap and low quality ESC.

Max performance aileron rolls are two notches faster without AS3X.  The quicker spin is also noticeably more susceptible to pitch coupling.  It's hard to know if that coupling results from gaining full aileron deflection or the lack of gyro input, but I suspect it is primarily the latter.

I flew in 3-4 mph wind.  The AS3X version has about a 5-7 mph wind limit.  Near the limits and with a few puffs of gust, AS3X might benefit intermediates more than manually fighting turbulence.  In calm wind, AS3X simply numbs much of the flying experience, and unlike the Beast/3D, the Gee Bee airframe flies without vice with or without it.

All told, the UMX Gee Bee flies beautifully without AS3X.  It is stable, true, and forgiving both fast and slow, and is more maneuverable toward it's naturally higher rotational limits.  I like it better without AS3X  Beginners, well, probably not so much, although they will probably run into some difficulty with AS3X churning too.

So the addition of AS3X was clearly to serve one purpose: to make the plane more beginner friendly.  Probably to minimize product returns.  AS3X is certainly not required for intermediate fliers, and advanced fliers would appreciate disabling it, or better yet removing it since it adds 10-20% to total weight from the larger board and increased battery demand.

Unfortunately for purists who prefer to more connected feel of the non-AS3X plane, the micro Gee Bee's higher kV motor needs the partially botched ESC upgrade on the AS3X main board to gain more access to full power.  I experienced OCP induced throttle cut off several times using an original UMX Beast board, even with the Beast prop, oddly enough.

I apologize for this lousy quality non-AS3X maiden video.  I left my HD camera's media card home.  I'll try to post a better quality video of a later flight:

Bottom line: Claims of AS3X miracles are 98.4% marketing hype. It was more likely intended to keep beginners who get in over their heads from returning bent product.

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