Friday, October 5, 2012

Monday, October 1, 2012

Align TREX 550E 3GX–Flight Review

INTRO                                                                                      

Along with my Align TREX 500E review, currently in progress, I’m going to add a 550E for those on the fence between these two awesome machines.  Aside from significantly larger size, this helicopter differs from my 500 in that it is flybarless.

zoom

SPECS
-
Length: 1042mm
- Height: 356mm
- Main Blade Length: 520mm
- Main Rotor Diameter: 1188mm
- Tail Rotor Diameter: 254mm
- Weight (With Motor): 1800g
- Flying Weight: Approx. 2800g

FEATURES 
- Align 600MX 1220kV motor
-  RCE-BL70G Brushless ESC
- Three Align DS610 digital servo's, one DS620 digital servo
- 520mm carbon fiber rotor blades
- 90mm 3K tail blades
- Align 3GX flybarless system

REQUIRES
- 7 Channel Radio
- 6S 5000 mAh LiPo

PAID
- $800

UPGRADES
- None Required



ON THE GROUND                                                                     

The 550 is a pretty big boy and it looks great…  

family photo front

TREX 550E, TREX 500E, Blade 400, Blade SR, Blade CX3, Blade 130 X, Blade mCP X, Blade mSR, Blade mCX

Component quality is industrial grade from nose to tail.  

The 550 is only sold as a kit, so barring someone else doing the build for you, there is no such thing as an ARF or RTF version.  Some might be put off by that, you are, my advice to you is not to get into serious RC helicopters.  The reason is simple: one way or another, you are going to do some damage to the machine, so you will need to understand it, in and out, to maintain and repair it.  Repairs take more time  than assembly, because you usually have to disassemble first.

Perhaps Ironically, the closer you buy to RTF, the more likely the helicopter is to crash for reasons beyond your control (mechanical or electronic failure) because the amount of time required to put a quality machine together is cost prohibitive, unless you do it yourself.

Like many, I started out with an RTF Blade 400—back when they made those—I never crashed it, it crashed itself.  The RTF Blade’s plasticy parts, from nose to tail did not last long enough to really learn how to fly.  My advice to those breaking into larger helis is to skip ARF/RTFs entirely.  The quality is not sufficient to get you from A to B, so in the long run, and even the short run, you’ll spend much more time keeping the heli maintained and airborne, not less.

Amazingly, Align twists the above discussion into good news.  The TREX series of larger heli’s are surprisingly easy to build.  The parts are counts is reasonably low and and assembly methods are simple.  The 550 is a simpler, more elegant design even that a pretty small copter like a Blade SR.  You can build a this kit in a day, start to finish.   If the 550 is your first big heli, it could take some just to understand the basic concepts of a torque tube, etc, but learning time is time you’ll spend regardless of helicopter choice.

RFsim

Align’s TREX 500 model for Real Flight

Speaking of learning, Align makes a superb TREX 500 sim model for Real Flight sold in Expansion Pack 3. The model is a little less stable than a real 500, let alone the 550, but it has a very realistic feel.  If you slow time down to about 70% to increase apparent stability, it can form the basis a of great training program for a 550.

The basic 550 construction method is a thick carbon fiber frame sandwiching a few basic components, with plenty of room to route leads and cables.  The servos are huge (metal gear digitals ) and come straight from Align, as does the matched 600 motor and ESC if you buy the complete kit.  The torque tube is easier to build than a belt driven tail, and eliminates any tension calibration guess work, not to mention that it flies so much better.

swashMy 500 review tests an “old fashioned” TREX with a flybar.  This 550 is flybarless.  Both fly beautifully. I actually slightly prefer the flybar’ed 500 for a little better inflight feel (I only do light 3D, due to lack of skill so I can’t comment on hard 3D feel).  Torque is slightly more evident when maneuvering with a flybar than without, but it is so fundamental to heli flying that isn’t necessarily a bad thing.

Where a flybarless design really shines is in ease of assembly and repair.   Make sure all three servos control arms are level, the swashplate is level (unlike the photo, which shows the blades stowed), and connect two perfectly equal length control rods from the swashplate to create a level head, and the helicopter will be very close to mechanically set up right from the first hover.  Easy peasy.

As the heli gets bigger, receivers seem to get smaller. I installed a Hitec Optima 9 to enable built-in voltage telemetry, give plenty of control, and immunize the high amp heli against receiver brownouts. 

Those installing Spektrum receivers should use at least two BECs, or a Castle Pro BEC with dual outputs, to prevent the strong servo power from putting the receiver to sleep and destroying the helicopter.  20 Amps of 6V receiver supply is a good target to keep voltage reasonable under load.  But there is no amount of amperage that can prevent voltage droop (infinite current required), so adding a dedicated, redundant servo/receiver battery will help minimize brownout-induced catastrophic crashes. 
 
frontquarter

Applying some brightly colored, self-adhering monokote to the landing gear and tail section improves inflight visibility and helps with orientation.


The 550 commonly flies with 520mm blades but I prefer 550mm blades for a more “600-like” feel.  Motor power with the larger blades is not a problem since the 550 uses the 600’s power system from motor to the ESC to the 600’s head.  In fact, there isn’t much that matters about the 550 that isn’t a 600, except the blade length, overall size and weight, making the 550E an incredible performer.
 
The maiden flight went well, I tried to keep it simple:


IN THE AIR                                                                               

BLUF
GENERAL CONTROL
BALANCE & AEROBATICS

POWER SYSTEM
ADVANCED HANDLING CHARACTERISTICS
IN-FLIGHT ISSUES
APPROACH & LANDING
OVERALL

GRADES                                                                                  

Appearance: +
 .

Aerodynamics: + 
 .

Power System: +
.

Build Quality/Durability: +
.

Value:  +
.

Overall Grade: +
.

Z8RC Manufacturer Rankings

RCrankings

Individual model recommendations are based on an overall grade of B- or higher.  This overall tabulation revealed that covers the 67th percentile and higher, of the top-to-bottom grading scale.   Roughly the top 2/3rds of the RC universe was good enough to receive the Z8RC stamp of approval.

Congratulations to the corresponding top 2/3rds of manufacturers who’ve received a Z8RC Recommended overall rating, as measured by their objective review performance.  Those manufacturers with fewer reviewed models are less statistically significant.

Z8RC is proud to be one of the only sources of objective RC ratings in the world today.  Most if not all RC review sites, RC magazines, RC groups and RC forums, take sponsorship money and a host of other forms of legal consideration from the same manufacturers they pretend to review.  IOWs, their model “reviews” are nothing but veiled, paid advertisements. 

If you see paid advertisements displayed on an RC website that contains a supposed product review, that is not a review at all, it is a bought-and-paid-for sales pitch.