Wednesday, September 12, 2012

BlitzRCWorks Mini F-22 Raptor with Gyro

I was intrigued when Banana Hobby upgraded their Mini F-22 to include a 2-axis gyro flight stabilization system, mostly because Z8RC crowned it the world’s “Most Fun Under $100” (well under).  More interesting, the price went up a whopping $6, to $76 to add flight stabilization to this sensational little flier.

gyro-1gyro-2Video frames from my hand launch showing a quick gyro correction

Banana has a stable of 50mm jets in the $70-80 range, and all have been upgraded to include gyros at basically no additional cost.  I decided to re-purchase the Mini F-22 so I could take an “all-else-constant” snapshot of Banana’s new stabilization system.

Unlike AS3X,  Banana has taken a non-integral approach to flight stabilization.  This is driven by the “Mini” series’ (slightly larger than an Ultra Micro at 20” span and 30” long) more traditional PnP approach, with discrete components like digital servos and high-amp ESCs, rather than bundling underwhelming components on an “All-In-One board.”  All-In-Ones are a generally bad values as they are a non-upgradable, a single point of failure for all components combined, and offer terribly low quality components like linear servos that let in dirt, jitter and die, often have bind and brownout issues, and feature “5A” ESCs that switch off power to the plane at around 4 amps.

As a discrete board, Banana’s gyro is entirely optional.  That’s a very good thing, because as we’ll see in this review, gyros aren’t all goodness.  Similarly, Z8RC was the first and only review site to fly the E-Flight UMX Gee Bee minus AS3X, only to discover the tiny Gee Bee absolutely flies better, with a more connected feel, without AS3X.

For those who think I’m simply bashing Horizon Hobby for padding their prices even more by adding AS3X, only to make the plane feel numb and less desirable, I reached exactly the same conclusion regarding the Banana gyro system.  The Mini F-22 absolutely feels less connected and flies worse with the gyro, than without.

Video follows:

All though it is obviously impossible to feel the plane while watching the video, you will see a few times when the plane pops up pretty hard from a downward flight path.  The reason is a lack of timely response to my up-elevator input, forcing me to add more and more until the plane finally reacts, too strongly. 

Stall behavior was slightly aggravated by the gryo.  I know this is an apples-oranges phenomenon, since the gyro likely fights the stall, somewhat unperceivably, until all control/airflow is lost.  To the gyro's credit, once a wing dips hard the plane does not try to completely depart controlled flight, but rather stabilizes in a turn until airspeed builds enough to straighten things out.

The gyro seems to reduce overall throw slightly, like most.

There are good things about the system.  In level flight with wind, the gyro seems to stabilize the plane well, but this plane was always a solid platform in some wind.  The plane also becomes a little easier to hand launch.

Banana’s gyro system is a lot more advanced than AS3X in that it allows gain control per axis, an expert and a novice mode, elevon mixing and servo reversing.  Better still, it can be moved into any airplane.

Additionally, as you can see in the video leader, the gyro's behavior is more than a simple rate mode countering short term perturbations, the control surfaces sometimes deflect very quickly, then very slowly bring the plane back to level.  There is more control logic built into the system than other gyro systems.

I want to stress that I did not play with all of the available settings, but given the default settings, I much prefer the flight characteristics of the Mini Raptor without gyro stabilization.  In fairness, the little F-22 is a sensational flier in basic form, and it’s basically impossible to improve on a great fundamental aerodynamics with computer cosmosity.  

Maybe other models in the 50mm series would benefit more from the new system.  Along the same lines, beginners might find the board more helpful than I did.

One thing Banana Hobby has done is strongly upstage AS3X.   The Banana flight stabilization system is a lot more advanced, tunable, transportable, optional, and for all intents and purposes, it’s free.

Grades                                                                               

Banana Hobby Gyro Flight Stabilization System : C-
Based on a single data point with default settings.  Thankfully, board installation is optional and the model price remains unchanged, so the airplane’s grade remains a solid A