Baron’s Hobbies – Online Hobby Magazine

Align T-Rex 450 Pro Super Combo- Setup and Flying

Posted on October 5, 2009 by aaronredbaron

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In the last two articles we introduced you to the Align T-Rex 450 Pro Super Combo, and built the helicopter. (click here to see the intro, click here to see the build) The build went very smoothly, and now its on to the good part, how does it actually perform in the air? With one of the most popular names in the hobby, this Pro version of the T-Rex 450 has a lot to live up to, but so far everything seems to indicate this little whopper is up to the challenge! With Align’s first torque tube in a 450, a redesigned main rotor head, counter-balances built into the tail blade grips, a full compliment of high end electronics, and a new lightweight frame design, this T-Rex should live up to its “Pro” designation.

Final Setup

Align included a full compliment of electronics matched to the demands of a 450 sized helicopter. Its interesting to note the first Pro kits were shipped with Align’s signature “outrunner in a can” motor design, but this kit came with a conventional outrunner, a RCM-BLM450M. The accompanying speed control, a RCE-BL35X, puts out 6 volts to the on-board radio gear. Going for DS410M digital servos on cyclic, with a transit speed of .09 seconds, shows Align is serious about producing a helicopter that flies well. Putting a high speed DS520 digital tail servo with a transit speed of .07 seconds with Align’s tiny GP 750 gyro means that fancy torque tube tail should be able to do its job. The GP 750 gyro is a pretty nice little piece of electronics; using simple one button programming and your rudder stick, you can set it for high frame rate or standard, digital servo or standard, set the gyros sensing direction, endpoints, and delay. Adding a Futaba R617FS to the model allowed me to control it with my Futaba 14 MZ, and I picked up a fresh Flightmax 3S 2200mAh LiPo, which is rated at 20-30c continuous discharge.

In our last article we completed the build of the helicopter, but we waited to install the receiver. Although most popular receivers will fit inside the frame, this requires removing the tail servo, and the wiring is difficult to access. I chose to mount my receiver to the outside of the frame. Its important to pay close attention to where the servo wires are routed around the gear train and the edges of the carbon frame. Be sure to secure the wiring so it cannot rub on the edges of the frame. If you want better access to the center cyclic servo, its as simple as drilling out the opposing holes to accommodate your hex driver. The servo leads on the cyclic servos are susceptible to being frayed at the edge of the case, they do not have a grommet where the wire enters the case. To prevent fraying, I recommend using a bit of Goop or hot glue where the wires enter the servo case, and anywhere you are worried the wires might fray on the frame. The tail servo features a nice grommet to protect the servo wire and doesn’t need this extra attention.

Test Flight

With all of the linkages in the head being fixed with the exception of the Bell input, I fully expected the model to track perfectly off the bench. I was surprised to find it actually was significantly out of track. I was able to get the blades to track, but when I went back to the bench and poked around with my calipers, it was obvious the Bell input links were not the same length anymore. After checking everything in the head, I determined one or both blades has a slight warp in them, test flights with another set of blades tracked perfectly with the linkages the same length. Initial settings of 30 on the gyro gain as indicated in the manual proved to work great, and I have yet to make any further adjustments.

Flying

• Hover and Forward Flight- With practically no slop in the head, the Pro exhibits smooth, locked in performance. Like the exceptionally popular bigger brothers it is modeled after, the T-Rex 500, 600, and 700, this model has a very predictable feel in hover and forward flight. It does not need expo to soften input around neutral, but delivers a linear response to your input, giving the pilot a very connected feel.
• Cyclic Agility- Minimal weight and a solid tail doesn’t hurt this category a bit, and the little Pro certainly delivers in this category! Cyclic response both in high speed flight and in tight maneuvering is very crisp and axial. Doing in place flips or rolls is easily achieved with the nimble little heli; its fast, crisp and doesn’t have any cross-control.
• Collective Agility- This heli has POP! It has the power and precision to do hard, aggressive stops, and it takes a beating and stays right with you, without any shimmy or hesitation. Align’s choice of servos helps here tremendously in producing a helicopter that is agile and still precise.
• Tail Response- This is perhaps where the biggest improvement is compared to previous T-Rex 450’s. This tail is fast, precise, holds very well, and is consistent. Having the tail dialed really opens up the helicopter’s capabilities, from keeping it on axis during in place rolls, to holding well through hard right handed piro maneuvers, to having minimal drag so the heli can autorotate, this tail works fantastic!

Conclusion

Align really hit the nail on the head with this 450. Any complaints I have about the design are minor at the most, and I have absolutely no complaints about the flight performance! It delivers fast, axial and aggressive 3D, while feeling very locked in and predictable. Its torque tube tail is perhaps the biggest improvement over previous versions, but this feature is also more susceptible to damage. If you drag the tail on the ground, you are almost sure to strip a gear somewhere in the tail drive. Torque tubes also get damaged worse in crashes than belt drive tails. If performance is what you are looking for, the Align T-Rex 450 Pro Super Combo is hard to beat in performance and value, but if you are not totally sure about keeping the tail off the ground, you might want to consider an option with a belt drive tail, such as Align’s new T-Rex 450 Sport.

Hits

• Simpler, lighter frame than previous T-Rex 450
• Crisp, axial, predictable response
• High quality electronics which meet the demands of the heli very well

Misses

• Poor access to the center cyclic servo and motor mounting screws
• Main blades warped out of the box
• Servo wires are susceptible to fraying where they enter servo case