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Friday, February 3, 2012

UMX Beast 3D with AS3X - Flight Review

Update 4:  Our Z8RC-exclusive Beast 3DS is now running on 3-cells along with last month's 3Sbach and also our 3Stryker 180.  See: for detailed instructions on how to create the exclusive Z8RC 3S version that is rapidly proliferating the micro RC world.

Also, a lot of folks from the Horizon Hobby fronted scam-review site rcgroups have been emailing me questions about creating 3S micros and also about the "yellow" Beast in my article below. 

As I said earlier, the yellow Beast is simply a protest of cowardly and unethical Horizon Hobby continuing to push and profit from the Beast mark after their act killed someone special, as well as Kevin Kimball and soon the NTSB aggressively blaming pilot Bryan Jensen for the fatal crash of the full size aircraft.  Enough is enough, it is unethical. low class, rude tot he family, you name it, to continue to push a brand for purely profit-motivated greedy reasons that, for all intents and purposes, folded with Bryan's death.  Worse, HH low class Beast products provide putrid value.  If you are going to exploit a brand that died, at t least give the proceeds of your rip off sales model to charity or to Bryan;s family, exclusively. Sheeze, what a bunch of losers.

Add to the mix of sour emotions that Horizon and Kimball insist on continuing to stir for their peanut profits, in my expert opinion the first-hand video shows clear evidence of mechanical failure.  That said, I have already stated my opinion that no blame be assigned to Kevin or his family aircraft company, since the full scale Beast was never required to be rated for the side-loads apparently impairing the structure and/or controls.   Nor should it have been; all pilots understand that extreme maneuvering a super-bipe into structurally unrated side-load territory is extremely dangerous and yet we do it anyway--rightly assuming all risk. 

The last thing we need is more regulation piled on regulation, more inspectors scooping-up government welfare pay, and even more, mostly ineffective rating requirements.  Still, Kevin wanted to keep trashing the pilot in his comments archived below, presumably to help save his own skin.  That is not necessary and it is low class.  See my commentary below for a detailed explanation of how and why the real Beast crashed and killed its competent pilot, and why the NTSB will weigh-in as they always do to shield the liability of the living and curry favor with industry.

So to answer the recent flood of rcgroups inquiries, no, there is no yellow Beast model, as discussed here a long time ago.

Update 3:  Great news!  Technology is catching up with the UMX Beast's poorly designed fundamental airframe balance.  The performance of the Turnigy Nano-Tech 120mAh E-Flite replacement battery trounces E-Flite's worthless 120 (and at 1/3rd the cost).  Positioning this 8g battery it so it disappears under the Beast cowling finally finally gives the UMX Beast usable wing loading and good balance with enough power to hover.   With good throttle management one can achieve a 5 min flight of mixed 3D aerobatics . Life is getting better for those saddled with E-Flite's semi-incompetent design house.


Update 2: Also see AS3X vs Z83X


Update:  I've tried the three potential E-Flite batteries in the UMX Beast 3D, the 120 mAh, the 180 and the 200.  Of the three, the 200 mAh is the best overall.  Although the plane is heaviest which detracts from already too high wingloading, pushing the heavier and longer battery back farther behind the cowling actually puts a small section of the battery weight on the other side of the CG see saw, generating a better (more aft) CG than the 180 and facilitating a more cooperative hover and better high alpha control--both of which are finicky without AS3X.  But unlike the 120 and 180, the 200 provides acceptable flight times at 4-6 minutes.  The 120 pushed way back, results in the best CG and min weight compromise, but the low capacity doesn't work with the new higher kV motor--at high power the RPM wobbles right away.

Original review follows:

Horizon's Hobby's new line of AS3X micros claim to revolutionize RC flight. Their claim is bold: "AS3X makes micro aircraft fly like an expertly tuned, giant scale model."

It's quite a claim, and frankly, it is pretty hard to believe.  Especially since most experienced RC flyer's have already flown larger planes with all manner of electronic gyros which form the essence of AS3X, and some are even installed on expertly tuned giant scale models--but I guess that's to make their 30%, 40%, or 50% model fly more like an E-Flite Ultra Micro.  Hah.  Not!

So let's see what it is all about...
  Wingspan: 14.7 in (374mm)
  Overall Length: 15.7 in (400mm)
  Wing Area: 83.8 sq. in. (54.2 sq. dm.)
  Flying Weight: 2.54 oz (72 g)
  Motor Size: BL180 2,500Kv brushless outrunner

While gyros may add to the flying experience in some ways, they may detract in others, and they represent pretty seasoned (= old) technology that has not been adopted by most RC aircraft makers.
In one breath, HH says this is an HH exclusive
revolution; in another, it is simply an adaption of existing
  technology"refined and tuned for 3-axis airplanes."
Neither statement is true.  Gyros are old school RC
technology that present a weight problem in lighter micros, in that sense AS3X could be very useful.  But installing gyros in any plane has pluses and minuses, which is why it isn't normally done and is rarely beneficial in an overall sense...

So before I flew AS3X, let's just say I was duly skeptical about HH's claim that they've revolutionized RC flying, exclusively.  They really try hard to brand their AS3X system as much more than a use of cheap, light weight gyros, which most if not all large RC houses offer on at least some of their models or as discrete black box add-ons. 

But like a kid who is a little too proficient at fibbing, they seem careful to never quite say otherwise. So as an easy comparison of similar "revolutionary technology" I recently outfitted my E-Flite Cessna 150 Aerobat with a GWS dual gyro system, purposely avoiding stabilized elevator on a floater, using these excellent, plug-n-play, fully trim and gain tunable piezo aircraft gyros.  Weight is 5 grams apiece, including all cord. Later in this review, I'll be using this tiny park flyer as a rough control platform to gauge HH's claim that the Beast 3D's behavior is on par "with giant scale models."  It should be an easy win for AS3X.

When the original UMX Beast came out, my expert review was the only critical voice on planet Earth.  I gave the first UM"X" a D+, mostly because the plane flew quite poorly per dollar spent.  And at a price-controlled $170, that was a lot of cash which ultimately translates to opportunity cost.  I noted you could buy a full size, exceptional 3D aerobat for the same or less. Meanwhile, every other "review" on the www, which readers of this blog know were never intended to be reviews at all, but paid-for, covert advertisements, bought and written for the express purpose of stealing your money.  They gushed with praise over the mediocre, UM-X-pensive, mini Pitts M12 look-a-like. 

The claims on the new UM-evenmoreXpensive Beast 3D box also reads like goofy North Korean propaganda:

Click or drag to the URL address bar to fully enlarge.

Ouch, they even use the term "world-class" right on the box, an outright no-no in modern sales.  It's a term that hasn't been en vogue since H. Ross Perot made a run for the White House in '92, and it is a term than makes savvy sales organizations laugh.  For good reason: it's meaningless and absurd.

It just emphasizes, for all Horizon's deserved success, the amateur nature of the underlying operation. And while were on the topic of amateurs, isn't it just a little tiny bit immoral to refer to the "full sized Beast" on the box, above?   I mean, come on Horizon!  Your sponsored aircraft crashed and killed the pilot due to what can only be assumed to be mechanical failure, based on the benign circumstances.

There is no full sized Beast. This outlandish financial milking of the full size Horizon Hobby Pitts M12 Beast is just so low class; it goes beyond the limit in my book.  HH should've simply halted their Beast line of models and apologize endlessly to Bryan's family instead of picking at wounds until the last dirty dollar has been extracted.

Back to the review...

Regarding the original UMX Beast and unlike everyone else in the world, I noted the CG was waaay too far forward, largely ruining the aerobatic experience and removing 3D flight as a possibility.  It was too nose heavy to hover, like balancing an oversize lollypop on the end of it's stick, the power system was too weak for 3D, and the 120 mAh battery was too short lived (even worse with the Beast 3D--a brand new, freshly charged 120 worbles right away). 

Additionally, the little Pitts seriously coupled flight controls, nearly uncontrollably at times.  The lack of a proper airfoil made slow flight unruly.  The plane used a proprietary 2S connection without including a plug for the charger. The original UM-Xtremely hyped Beast flew reasonably well with the 120 mAh battery stuffed so far back you couldn't see it, and as long as you paid expert attention to the rudder, and had an outdoor venue big enough for a small parkflyer and 20/15 vision. Most people were shocked at my accurate assessment and grading, to say the least.

Fast forward to today... 

Horizon Hobby now says the original UMX Beast (which they marketed at the time as a modern miracle) was a too poor of a micro flier to control in an indoor venue, and that it had the CG too far forward making 3D flight impossible.  Confirming everything I said, while tacitly admitting they have a small problem telling the truth.

Against this historical Beastly backdrop, let's just say I was skeptical at best when HH started making claims about developing a technology so powerful, that it eliminated Reynolds Number as an RC modeling concern.

On the Ground:

The UMX Beast initially impressed me in one way: the price.  Presumably, ever since the AS3X UMX Beast was conceived, HH dropped the price on the original UMX to $99, making it one of the better deals on the Horizon shelf at least while obsolete inventory was peddled on unsuspecting buyers.  It must have felt like quite a slam when recent UMX Beast buyers saw the newer UMX Beast 3D announced as a BNF for just $130, after spending between $100 and $170 for the old variant.

Well, those who feel ripped off can start feeling better, this "BNF" is not "Bind-n-Flyable" at all, that label is flat-out false advertising. There is no charger--at least the original UMX Beast included an unusable charger, with no plug.  And there is no charger for good reason:  no battery, making the UMX Beast both un-bindable and un-flyable for most customers, and to every customer as it sits in the box.

HH needs to correct this problem ASAP by providing a mail-in battery and battery charger (with an AC plug) as a remedy to this intentional false labeling, with two-way postage paid.  This is yet another premeditated Horizon Hobby rip off.

Note the omission of a battery and charger.
Until HH corrects this in-your-face scam, the cost to actually "bind and fly" the UMX Beast 3D "BNFU" variant is somewhat staggering:

In addition to adding another proprietary and shoddy E-Flite 2S battery to bolster my rapidly failing E-flight UMX LiPo inventory, I was also looking forward to a more powerful Beast with a better CG since HH said so in their advertising.  

Well, guess what?  It's not more powerful and the CG is worse.  It's still got a 180 brushless motor, they've simply upped the kV slightly.  That is different gearing, not more power.  The exact same thing could have been done by providing a different prop pitch.  It has no battery, but the 180 mAh battery recommended to cope with the increased amp draw of the motor re-gearing makes the CG even worse. Violated.  Again.

So I know many are thinking... I can't possibly be objective with the rest of this review.  That's wrong, it's easier to call it like I see it than lie for peanuts like all the popular RC review sites and magazines. 

In the Air:

Since I have already reviewed the UMX Beast, I will not recap flight characteristics unless it pertains to the addition of AS3X.  I decided to do this flight review in three basic parts: (1) performance of the AS3X Beast 3D in calm winds, (2) performance in 3-5 mph wind, and (3) in the same winds as #2, a direct comparison to a small scale (18 oz RTF with battery) gyro-stabilized park flyer.

#3 is really to shed light upon the HH claim that the UMX Beast 3D flies like a giant scale expertly tuned airplane--or, stated another way--if the AS3X Beast 3D outperforms, or performs similarly to a small 38" park flyer, then HH's claim could potentially be correct.  If not, then the claim has been proven false.

Let's jump right into #3:  Horizon Hobby's claim that AS3X creates an experience similar to flying a giant scale airplane is false. In 3-5 mph wind the Beast 3D got battered much more severely than my smallish 18 oz park flyer.  I'm not only talking about its lack of mass, though that is a huge handicap, but also with regard to the gyro's general setup and capability. 

Fundamental to the so-so performance is the basic platform, which has not improved one iota. As a side note to this test, I also flew my 55" J-Power P-38 in the same conditions.  It was barely impacted by the wind and behaved beautifully (as always).  The difference between flying this 39 oz park flyer and the micro Beast 3D in light wind was HUGE. 

Here are the two videos, taken within minutes of one another.  The small park flyer with a 2-axis gyro is an order of magnitude more capable of absorbing these 3-5 mph winds and corresponding puffs and gusts. 

I landed the Cessna 150 with 11.3 Volts remaining at cruise due to darkness.  It might seem odd comparing a Cessna 150 to a Pitts M12, but in this RC form it is not as far off as it might seem.  Sure, the Cessna was used out of convenience, but it is very aerobatic--it actually hovers and knife edges better than the UMX Beast 3D.

Backing up to #2:  The Beast 3D is notably better than the original Beast in light wind with regard to stabilized maneuvers, like brief hovers, harriers, and knife edges. That said, the UMX Beast was always better than most micros in wind, because of its heavy nose and high wing loading.  Both of those, unfortunately, are at odds with X-treme aerobatics. 

The Beast has not changed, fundamentally.  In fact, it is slightly worse than the original Beast in stock form, due to weight gain. This was a pretty disappointing revelation.  Why wasn't the UM Beast evolved and improved?  The basic airframe has core design issues, primarily it remains chronically nose heavy.

I blew off the E-Flight recommendation to buy a 180 mAh battery, as it would've made the nose heavy condition far worse.  I stuck with the original Beast 120 mAh 2S, but used a brand new one (zero time prior to the maiden); my original Beast battery gave up the ghost after a just few flights.  The 120 is a better choice for balance, but flight time is even shorter than before with this higher kV iteration of the same motor, and the motor worbles from amp deprivation almost immediately when running flat out. Expect 2-3 minutes of mixed flying with careful throttle management, and only one or two few-second opportunities to try to balance a hover.

Even with the lighter nose, and with AS3X jittering away, the Beast is still reluctant "to 3D."  The plane is fundamentally out of balance even with the battery shoved back until it disappears.  It doesn't want to glide on a CG, it craves dirt without power-on, and it wing rocks unnervingly when plowing through a stall.  If I were approaching this UMX Beast 3D review from a non-AS3X perspective, the model generally behaves worse than I would expect from a Pitts M12 rendition at any scale. AS3X definitely helps fight the CG problem.  The gyros help resist slide off, like a propping medicine ball on a seal's nose.  But when the nose does slide off, and it often does, it falls off even harder than before. 

Surprisingly, AS3X manages to allow flailing wing rock.  And like all gyros, it takes some practice to learn how to coax the gyro to play along with you rather than fight against you.  And like all gryo solutions, the plane occasionally gets ideas that aren't yours. I almost lost the plane during #2, because the wind + AS3X was able to trump my inputs on low rates--the plane didn't want to accomplish a level turn in time to stay out in front of me, nearly dashing it against an always-too-close-to-my-flight-area rock ledge.

And that's the problem with all aircraft gryos--they also dampen the way the plane reacts to you.  Yes, I know they theoretically allow your flight control inputs to burn through, but only on the axis you are trying to control.  The way the plane naturally reacts to developments on another axis is also dampened. 

For example, if you bank and pull with some positive AOA on the plane, the yaw dampener will try to force a slip, slowing the turn rate (which can make rocks bigger). As you put the plane through its aerobatic paces, you often feel the gryos working against you.  And that is fundamentally why gyros are not a staple on all great flying airplanes, and if they are used, it is best to be able to gain them up or down, or turn them on/off in real time.

AS3X applies aggressive corrections all the time, with no way to de-tune it.   If you watch the lead-ins on the comparison videos I uploaded below, you'll see that the UMX Beast gain is juiced a lot more than my own implementation of tunable gain gryos on the small park flyer.  And that's to affect 1/8th the scale.  In general, I felt the Beast 3D gain was set several ticks too high. That said, I recognized the need for a lot of help with the anvil nose, so it's probably gained-up by design.  That decision is riddled with side effects. 

As a result, AS3X often makes multi-axis aerobatics feel numb and disconnected, and at times generates somewhat unpredictable lethargic reactions when one expects a more traditional, snappy, aerodynamic flight path change. 

That brings me to #1, where AS3X shines the brightest. In calm winds and more subdued flying, the plane hands over its most connected feel.  But it is still noticeably more distant than a conventional Beast.  It is tempting to say that calm winds present the least challenge, so AS3X is helping to solve a non-problem.  But that isn't completely true because the Beast also displays substantial coupling which AS3X mostly removes, like executing a clean sustained knife edge.

As far as hovering, it definitely helps.  In calm winds brief hovers are possible, but fall off exponentially as the nose departs usually in the pitch axis, and the power system is marginal in pull and stamina.  It provides a basis to start practicing, though I suspect obtaining more stabilized hovers will require skills unique to this particular aircraft and gryo system.

Before I answer the obvious question:  is AS3X a worthwhile improvement?  I have to mention one more thing: skill development, and for that matter, the gratifying feeling that accompanies improvement.  AS3X dampens that too.  Sure, AS3X can help substantially given the right circumstances. 

One, is to make an advanced novice routine look a little more pure.  Another, is to help corral the airplane's bad habits, or at least help delay the inevitable. Personally, the first doesn't appeal to me that much, because you aren't learning and its debatable whether the overall impact of AS3X is a net positive on precision anyway, at times it feels pretty numb.  You'd probably get used to it, but that's not a highly transferable skill. 

AS3X helps at times, but it is no substitute nor does it approach the raw capability of a proper flying airplane.  And similarly, sometimes suppressing airframe vices invents new and more creative ones. Most advanced fliers have already experimented with gyro stabilization.  It is really interesting, but my experience is that it soon gets removed from a great flying airplane.  The UMX Beast is one airplane where I'd probably leave it installed. And so, on to final judgement. 

Is AS3X worth it?  I wish I could give a one word answer.  If I could, I would.  I can't. UMX Beast 3D/AS3X Conclusions:

  • AS3X generally helps do maneuvers that tend to stabilize--brief hovers, harriers, knife edge flight--the 3D signature stuff
  • It occasionally fights you during maneuvers that do not tend to stabilize--pure aerobatic flying
  • It generally numbs the feel of the airplane, which advanced novices may have yet to acquire
  • Gains are set too high in this implementation--but the unruly Beast likely demands it when nose high
  • It does not even approach the feel of small, properly set-up, competent parkflyer, but can move the micro experience a step in that direction
  • The Beast is still too nose heavy, made worse by the larger battery demand.
Given the choice of the two Beasts:  I would grab the lighter, original Beast on a calm wind day for its more pure aerobatic experience, the thrill of carving well coordinated, floating slow fight along a precise path through space, and its lighter wing loading resulting in better overall agility.  I would grab the UMX Beast 3D on a slightly bumpy day, or for somewhat cleaner execution of the more unnatural looking, hanging maneuvers that the UMX Beast cannot aerodynamically isolate.

The difference between the two is very much evolutionary, not revolutionary, and the delta is not all positive.

As far as issuing grades, I do not think the addition of AS3X changes my initial assessment of the UMX Beast aircraft.  Although the gyros provide a degree of help holding certain aerobatic poses, their impact often frustrates tracing well coordinated lines through still air.

HH should contain the use of AS3X to improving the flight characteristics of airplanes and helicopters with otherwise impaired manners.  So far, that seems to be their strategy.
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