Review: BEASTX- Be Absolute Stable

I have gone FBL on the E-raptor. I got the beastx because it was cheap and got good review. I had been battling a vibration issue on my e-raptor. It was shaking like mad with the RJX flybarred head from the xtreme 50. Yet with the stock head, it was dead stable and smooth. So problem was with the head. I couldn't find anything bent and wasted a lot of time troubleshooting it. In hindsight, it was probably my fault because I HAD OVERTIGTHEN THE ROTOR BLADES. That is it. Simple and silly mistake...more on that later.

The first time I saw a FBL flight in real life, I thought the heli had extemely fast cyclic rates, so fast that it wasn't really practical and the pilot was bogging the heli...mind you, it was a electric 700. TBH, I never saw the need for FBL and still don't after flying it. After all, whatever that I can do is hardly limited by the heli. I am not sure if it is my setup or what, but there is nothing special about it, it FLIES EXACTLY LIKE A FLYBARRED HELI. Perhaps then, I got a GOOD FBL gyro because it is suppose to fly like the flybar is there, even though it isn't. :P

I spent quite a bit of my time doing my FYP report past few weeks...so on the night that I printed the first draft, I thought I just had to reward myself with a new toy. New lens? Nope, I have all I need at the moment....or rather, I can't afford the next level lens without thinking twice or thrice or... 35L and 85L are what I am looking at. Convert the 700N to electric? No point. After "touching up" the interior of my 91sr and using the hatori, it is now so powerful that people compliment my collective management skill. Haha, if only they know what a little bit of sanding and polishing can do. Well then...how about FBL conversion, since the e-raptor is having vibe issue and I have wasted months fighting it. Deal. FBL.

A check on the online shops shown the V-bar to be around S$400+5.1pro upgrade+shipping+FBL head=$650. That is crazy money for a beater heli. So I settled for the second best...BEASTX. After a night of thinking, I msg heliguru.sg. It seems price of the BeastX has come down even further.

After a few sms, I got these on my table.

BeastX with RJX 50 size FBL head.

Box opening. BeastX is tiny.

All necessary connection wires and tapes were included. I mounted mine with the supplied white foam tape.

It is really tiny, even smaller than the R617FS rx.

RJX head. Nice value for a $125 head.

The package is really complete. Ball links, linkage rod, washout hub, and even blade spacers. Wow. Bling bits were nicely protected by the foam wrapper.

Unforunately, the headblock wasn't so perfect. One of the screw hole was off. Dealer promptly replaced it.

This is how it should have been.

I was lazy to take photo for the build process...but it is pretty much a standard affair. The installed head...it is really a simple and fast build because of the low part count. I only had to thread two push rods..

BEASTX mounted.

FBL e-raptor.

First Flight

Having watched more than a few videos of FBL heli tipping over on the ground during maiden, naturally, I was excited and nervous. The exact same feeling you get when learning to hover for the time. Fortunately, maiden went without drama. All I did was hover and hover and more hover.

Second Flight

Then it came time to get the headspeed up to where I usually fly-2250rpm. Again, I was filled with anxiety because I had read about FBL heli tipping over when switching to idle up simply because of the vibration inducing weird behavior. Took a deep breath, flipped the idle-up switch and it started wobbling. The exact same wobble I get when hitting the resonance headspeed of the damper. Regardless, I took it up for a few flips and rolls. Things were fine, it just felt disconnected and weird, negatively weird.

Subsequent flights....

Having turned down the cyclic gain, the wobble was gone. However, the heli developed a slight vibration, similar to that from the RJX flybarred head that I was running. After a whole day of troubleshooting, I found the problem source. I had over-tighten the blades. In hindsight, the rjx flybarred head was probably fine in the first place with the vibe coming from over-tightened blades. The heli flew exactly like a flybarred heli. I was initally worried that my piro-flips and piro-tic-tocs will be affected, but test flight shown my worrys to be unfound. The BeastX was ran in sports mode, which some have commented to have slow rates. Yet, I found it to be pretty good. The piro and cyclic rates are similar to what I usually run. Only issue I had was that it seem there was a little too much expo softening the cyclic around neutral. So I might go "pro" mode soon.

The biggest difference between FBL and flybarred is the variation in roll and pitch rate with headspeed and airspeed. In a FBL heli, the cyclic response for a given cyclic input is the same regardless of whether you are stationary, doing FFF, running a super high headspeed or doing autorotation. Whereas in flybarred heli, the faster the heli, the faster the cyclic repsonse will be. Similarly, cyclic reponse will sharpen and increase with more headspeed. Because I have been flying the flybar for 10 years now, my fingers have been conditioned to this fact, which meant that there were some unexpected moments in the few test flights. For instance, in an auto after the flight, the cyclic sticks can get shockingly sensitive as compared to what I am used to. Another hairy moment was trying to pull out from a very fast tail slide, where a little elevator input would have been sufficient for a flybarred heli, but not quite for a FBL one.

Setup is actually very simple. Just follow the given instruction with a little bit of common sense and it is done. There is no need for any fancy transmitter mixing or compensation or settings. I left the cyclic servos update rate on the default 50hz and the heat sink was already getting warm to touch after 3mins of hard 3d. So I guess the recommended 200Hz might be too much and I don't think I want to try it at the moment. It seems that FBL really does put some load on the cyclic servos. Being lazy, I left the logitech 6100g servo in the e-raptor and ran it on 960us 333hz. As usual, it is running pretty hot.

I do agree that FBL is the future, just like electrics over nitros, but you probably won't catch me with a FBL conversion on my 700N any time soon. I don't hate FBL, but it is just that I can't really feel the difference between a good flybarred setup and a FBL one. At least not significant enough to justify the extra money spent and extra load on the servos and BEC.