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Align's T-Rex 450SA ARF Mini Helicopter

Steve Kaluf reviews the exciting new Align T-Rex 450SA ARF Mini Helicopter, distributed solely by Horizon Hobby.



Main Blades:Align Pro 325mm
Weight:21.5 oz. (with battery) 15.2 oz. (without battery)
Servos:Head-JR DS285, Tail Rotor-JR DS3400G
Gyro:Align RCE 500X
Transmitter:Spektrum DX7
Receiver:Spektrum AR7000
Battery:Align 2100 LiPo 16C
Motor:Align 430L 3550 Kv
ESC:Align 35G
Street Price:$199.99
Price as Tested (includes: T-Rex, Servos, Battery, Gyro, ESC, Motor:$629.91
Manufacturer:Align Corporation
Available From:Horizon Hobby

The T-Rex 450 SA ARF is the latest in the Align T-Rex 450 size helicopter series. This version is exclusive to Horizon Hobby Distributors (and therefore all dealers in their distribution network). For most T-Rex pilots this is excellent news as Horizon has a reputation for keeping parts in stock and all T-Rexís in this size range have interchangeable parts. You can upgrade, mix and match parts to your heart's content. If you have a T-Rex you probably have more than one.

The SE version with itís stacked carbon frames and metal everything else is the top end of the current T-Rex food chain. The SA fills the gap between the SE and the other 450 versions. It features many of the upgrade parts that the SE has, but it is considerably less expensive.

The T-Rex 450 class helicopterís performance is legendary (and theyíve only been available for a few short years). Few helicopters can match them in overall performance. They can all go from mild to wild with just a flip of a switch. Let's see how the SA stacks up to the others.

Kit Contents

Required to complete this machine:

  • four servos (three sub-micro with at least 17 oz/in of torque, one sub-micro-mini servo for the tail rotor control with transit speed in the .12 sec/60 deg. or faster),
  • gyro (heading lock preferred),
  • 430 class brushless motor (3150-3550 Kv),
  • 25 amp or greater electronic speed control,
  • 3-cell 2000-2200 mAh Li-Po battery pack with a 12C or higher discharge rate (15C min for 3D),
  • your favorite 6-channel helicopter radio system.

For the purposes of this review I selected Spektrumís brand new DX7 spread spectrum radio on 2.4 GHz. The Spektrum line is also distributed exclusively by Horizon Hobby.

Editor's Note: Horizon mentions that the DX6 would also be an excellent choice for this size/type of model.

I selected the JR DS285 digital servos for the head and the new JR DS3400G digital servo for the tail rotor pitch control. I could have easily used E-flite/Spektrum S75ís for the head as well. The instruction manual gives specifics about the installation of both of these servos as well as the DS3400G. The S75 is an excellent servo for sport type flying, while the DS285 offers the ultimate in control and precision for a slightly higher cost. The DS3400G is a blindingly fast servo that is perfectly suited for mini-helicopter tail rotor control. With transit times of .11 sec/60 degree at 4.8 volts and .09 sec/60 degrees at 6 volts this servo is one of the fastest available today, and speed is definitely every pilot's friend for a tail rotor servo!


The SA has some unique features that differentiate it from the other T-Rexís in this class. It has stacked aluminum frames, many updated composite parts, and is 95% pre-assembled so completion goes very quickly. The steps are primarily installing radio equipment and detailing the canopy to your liking.


  • machined aluminum main rotor hub
  • aluminum & composite swash plate
  • stacked aluminum frames
  • composite blade grips
  • gun-metal grey, great looking aluminum frames
  • machined aluminum cap washers under every frame fastener -- looks and quality!
  • 120 degree CCPM head -- Iíve really grown to like this set-up; I find it very precise, strong and easy to set up.


The instruction manuals that Align has produced for each of the T-Rexís have always been excellent. Iíve been critical of a few minor areas in the past. However the SAís manual fixes all of my previous complaints. Horizon has been known for excellent manuals in the past and I suspect they wrote the majority of this manual.

One thing I really liked about the SAís manual is that it gives a few different equipment installation options or suggestions. This gives the modeler a few ideas to make the installation suit his equipment the best. Even though I have an SE version and have previously played with different installations in it to get one I liked, I found a better idea in the SAís manual for a couple of things.

Routing the wiring in a mini helicopter is always a daunting task to make it all look really neat. Again the SAís manual shows a few different (neat) ways to do this, depending on how certain components are installed. My end result was a much neater overall installation that the one I have on my SE. So much better that Iím going to change my SEís installation to match what I did with the SA!


Assembly, as previously mentioned, consists mostly of installing the radio equipment in the model.


The manual covers installation for JR and other brands of servos.

Servo mounting hardware is included in a separate parts bag. This bag includes servo mounting plates which are basically flat plastic plates with a reinforced hole in them. They are more or less used as nuts for the self-taping servo mounting screws.

I really like these JR DS285 servos! They have excellent resolution, little, if any dead-band, are fast and have plenty of torque for this application.

Head Servo Mounting

The manual shows very specifically how to install the sub-micro servos for the head, indicating the proper orientation and what, if any, need to be removed from the machine to make servo installation easier. The photos are very clear and detailed; this adds to the overall simplicity of the machine's assembly.

It is important to pay attention to each servo's orientation. The manual tells exactly how to install them.

I was pleasantly surprised at the servo mounting arrangement. With the SE version, the complete servo mounts between the frames. As shown in the photos, on the SA, the two front servos, pitch/aileron servos mount in between the frames. The rear (elevator) servo mounts with the output arm in between the frames, and the rest of the servo sticking to the outside of the frame. There is certainly nothing wrong with the SAís arrangement, both work perfectly and the method the SA uses is certainly easier to install. The canopy mostly covers the rear servo, so it really isn't noticeable.

The servos are held in place by plastic mounting plates. These act as nuts for the sheet metal type screw provided for servo mounting. These plates do their job well, but I do find them a bit of a pain to install. I had to hold them with a pair of forceps or needle nose pliers while I get the screw started and tightened. This is difficult at best in between the frames. I managed to squeeze too hard at one point and shot one across the shopÖI never have found that particular mounting plate! But they do work and using them means I donít have to use grommets or eyelets to mount the servos.

Align RCE 500X Heading Lock Gyro

I choose the Align RCE 500X Head Lock gyro for this machine. This is the first time Iíve used an Align gyro. It is a nice small and light unit that has worked VERY Well.

I decided to mount the gyro on top of the boom mounting block. Some may prefer under the boom or inside the canopy as it will protect the gyro better in the event of a crash. I mounted the main receiver between the frames under the main gears; the remote receiver for the DX7 under the tail boom block. I think this really makes for a neat installation. The only component under the canopy is the battery pack.

This setup does leave the bird a little tail heavy. Not bad though and for now Iíve just put in a little ďforwardĒ elevator trim to correct for the condition.

Align 35A ESC

This is my second Align 35 amp ESC and I have to say I really like them. The ďGĒ model has an additional feature over my original model-- throttle response.

The programming features/my settings for this ESC are:

  • Throttle Response (slow, moderate or fast. I chose moderate.)
  • Brake (set to disable),
  • Motor Timing (When using the Align 430L 3550 kv motor, I set to mid timing for better efficiency),
  • Aircraft Option (Airplane, helicopter soft start, or soft start with governor mode. I chose the simple soft start mode. I like this mode as it is easier on the machine and it also gives the pilot a chance should there ever be a hot start.)
  • Battery Protection

NOTE: Battery Protection offers three different cut-off voltages. I selected the high protection mode of 3.2 volts/cells. This is a very conservative setup. If you are into 3D or other hard core aerobatics youíll probably want to select the 2.9 volts/cell setting so that you donít get a motor shut down during the high loads of aerobatic flight.

This ESC is programmed by positioning the throttle stick on the transmitter. Iíve found it to be easy to program and it delivers excellent performance.

Align 430L 3550 Kv Motor

This is a pretty hot motor that will be adequate for even the most aggressive 3D flyer. Even with a 3550 Kv rating, Iíve found the motor to be fairly efficient. My run times with a 2100 pack are easily in excess of 12 minutes.

Spektrum DX7 Spread Spectrum System

I decided to use my new Spektrum DX7 spread spectrum radio system with the T-Rex. I plan on flying this machine at many indoor events where this is typically a long waiting line for the 72 MHz frequencies. The DX7 allows me to simply fly when I want! I also wanted to have the very connected feeling that the DX7 provides. This radio has some of the best latency figures of any radio system, so when I move the sticks the servo moves virtually immediately. The system is also immune to almost all sources of outside interference. In an electric helicopter this is certainly a plus. The DX7 also has plenty of helicopter programming features. The system has worked perfectly during all of my flying with this machine.

Note: My new DX7 is also compatible with the DX6's AR6000 receiver.

Linkages -- Simply Perfect

Typically, when building a helicopter, the linkage rods are one of the first steps. This means there are a bunch of rods laying around that can get mixed up. My trick to keep them straight is to stick them to a piece of masking tape with the rod's number or letter written on the tape. Fortunately the SA has only a few linkages to assemble and the head is already completed; so, I just attached the rods to the head as I finished each one. The manual provided three different measurements for the linkages (rod length, center to center of connector length, and overall length). This makes assembly of the control linkages very easy. The hole in the ball link ends is a little tight to start on the rods; I used a hobby knife to open the hole in each ball link up just a little bit to start them onto the rods much easier. Please use a good caliper to measure the rod lengths. If you do you will be rewarded with a machine that virtually flies right off the bench. The measurements in the manual are exactly accurate.


I did find one problem during final set-up of my SA. When I attempted to adjust the collar under the swashplate to take the play out, I found that the collar had a burr inside of it that would not allow it to move on the main-shaft. To fix this I pulled the main-shaft out, cleaned up the shaft with a jewelers file, installed a new collar and reassembled the head. This whole process took maybe five minutes. I bring this up to point out that this is a very easy to work on machine.

The manual provides programming details that will work for most transmitters. Like the measurement for the control linkages, take care to do the transmitter programming accurately. Mini helicopters are very sensitive to proper setup. Done correctly, the T-Rex will fly like a .90 size machine. However, if you are off on your setup you will know it. Every good mini helicopter teaches its pilots a great deal about setup.

The ESC and battery are both supplied with a new connector called EC3. Horizon has a complete line of charge cables featuring this connector. I like it! The connector has keying that will not allow wrong polarity, and the raised ridges on it make it much easier to disconnect than many other connectors.


Next comes the fun part, flying! I always do a through pre-flight on the bird, again the excellent manual gives some good suggestions for what to check. Make sure the gyro direction is set properly and that the head moves in the right direction. Double check the ESCís programming, lube the main shaft around the swash plate and the tail rotor shaft. I also recommend spraying the tail rotor belt with a little WD-40. This will prolong the life of the tail rotor drive belt and keep static electricity build-up in the tail boom to a minimum.

The T-Rex SA is a very powerful machine in a small package. There is virtually nothing it cannot do. Itís collective authority is very high, yet it will settle into a perfectly level hover with no problem.

I found the T-Rex will hover hands off when flown indoors with out much difficulty. Some collective management is necessary but thatís about it.

The Align gyro performs very well in the heading lock mode. It does have a slight tendency to need some trim to correct drift during the course of a flight or if the temperature changes much. However when coupled with the DS3400G servos it gives very positive control of the tail. Sideways flight (fast or slow) does not seem to have any effect on the gyro.

The DS285 servos on the CCPM head give very precise control. This coupled with the speed and resolution of the DX7 system I used with the T-Rex gave me an almost uncanny connected feeling with this machine.

The 430L motor has gobs of power and performed flawlessly during all testing.

The Pro 325 stock blades provided with the SA are excellent. They track perfectly and have tons of collective power. They also hover and slow fly very well.

Flight Video/Photo Gallery

The first video provides an idea of its slow, stable flight characteristics. All three videos were shot during the JR Indoor Festival in Columbus OH, in November (2006).

Iím not a 3D pilot so I enlisted the skills of Team JR member Scott Cathey to be the pilot for the 3D videos. As you can see Scott is an excellent 3D pilot! The first video is three minutes of hard core 3D just for the camera. The second 3D video is part of the noon-time demonstration that Scott flew at the festival. The only non-stock parts on Scottís bird are the main rotor blades. He was using the new V-Blades for the T-Rex.


Editor's Note: Due to some sort of technical difficulty, the videos play at an accelerated frame rate in some browsers. We are working to resolve this problem and apologize for the accelerated play rate on some computers. New videos will be uploaded as soon as we resolve the issue.


For both precision aerobatics and 3D this machine sets the standard by which all other mini-helicopters are judged. No other mini I've flown even comes close. As I mentioned previously I also have the SE version of the T-Rex. Iím very happy to report that the SA version flies every bit as good as the SE; and the SA is a whole lot less money!

When flying indoors, I had to be aware of how much collective authority/power this bird has. Punch the collective and it is climbing towards the ceiling very quickly!

I cannot imagine an aerobatic or 3D maneuver this bird could not do with proper setup. When pressed by my editor, I could neither pinpoint one manuever the SA did "heads and shoulders above all others", nor anything in which it disappointed me. In this class of helicopters, it is so critical that the model be able to string the series of maneuvers together, cleanly and accurately. This is one place where the SA truly shines. Whether at top speed or hover, the SA did everything we asked of it, cleanly, precisely, impressively.

The two 3D videos will tell the real story of what this machine is cable of.

Author's Note: Scott did only one modification to his bird and that was cutting the horizontal fin down to a much smaller size. This is normal for those doing a lot of 3D. The fin is not a help to 3D flight and making it smaller allows the bird to flip faster.

Is This for the Beginner?

Many feel the T-Rex does not make a good beginner machine. I donít share this opinion. I believe it can be a good beginnerís machine. To work as a beginnerís machine it must be set up less responsive than an aerobatic or 3D pilot would want. It is a stable machine and with training gear it is very easy to lift off and land. I also feel itís predictability makes it easier to fly than some small machines sold as beginner machines. Plus, it can grow all the way through 3D as the pilot's skills grow.

If you are not ready for a very maneuverable, powerful machine I encourage you to dial in some exponential and/or dual rates and take things slowly. Fortunately the T-Rex is also a very stable machine. It is very predictable only going where you tell it to go.


As you can probably tell Iíve become a bit of a T-Rex fan. These machines are so good that they tend to get in your blood. The value they provide is excellent. Alignís use of higher end parts where needed is almost perfect. The SA provides just enough ďblingĒ to keep most of us happy without going overboard and driving the price up.

Horizon Hobbyís exclusive version the 450 SA ARF could very well be the perfect mini-helicopter!

Last edited by AMCross; Nov 25, 2006 at 02:43 PM..
Thread Tools
Nov 23, 2006, 09:03 AM
Suspended Account music during vids. Pilots want to hear the sound of the aircraft.
Nov 23, 2006, 11:48 AM
Registered User
What a huge amount of new articles we got today!
Nov 23, 2006, 05:53 PM
Jay C's Avatar
Yeah, and no country music at that :P Seriously, the 3D action was so fast paced I'm blown away! Kudos tot he camera man that never let the bird out of view.

I would have loaved to hear the buzz of the blades beating the air into submission though.
Nov 23, 2006, 07:09 PM
Heli Monger
eMeNeX's Avatar
Hmmm Not a big fan of the production of those videos... The 3d Videos were running at 150% of normal speed. The music weas god awful. There should be no music or if there is make it minimal in the background, lets hear the sound of the craft for bogging and blade noise.
Nov 23, 2006, 07:16 PM
Ship first, Improve often
L0stS0ul's Avatar
yea it was almost like the video was sped up. It seemed like it was at least twice speed. Don't know if the music made it look that way or if it really was that fast but dang.
Nov 23, 2006, 07:47 PM
Registered User
well, I was hoping to hear the sound of the mian blades when it came time to spool her up to liftoff speed, and while flying, but the music was too loud. oh well, still nice flying! I am far from any 3d. I love my SA! cheers, scott.
Nov 23, 2006, 07:54 PM
Heli Monger
eMeNeX's Avatar
It is sped up.
Nov 23, 2006, 09:18 PM
Registered User
Crowfly's Avatar
Christmas hype. Although I took the bait a few days ago
The expert lubed the belt with WD- 40.Is that not a no-no?
I believe this is a realy good helicopter.
I feel we are very fortunate to have the internet so we can report our findings. I also believe it's overpriced.
But like I said,I took the bait and I bought one. I think it's versatile and can't comment further until I get it flying. Happy Turkey day Fred
Nov 23, 2006, 11:47 PM
FPV for Me
TaSaJaRa's Avatar
It was a good review, But I would have like to hear the T-Rex not the Country music.
You want to get an idea of what's going on with the Heli as it flys.

Music is great when it's not a review.
Nov 24, 2006, 01:06 AM
Hoverup's Avatar
What radio system was used for the 3D flights? It didn't appear to be the review DX7 Spread Spectrum system that was used in the hover and test flight video. The Tx antenna that shows at the end of the 3D video is why I am asking. Was it the review airfame being put through the 3D paces or another Rex? Good review and video, but as others have said let us hear those rotors beating the air into submission and lose the music.

Cheers and Happy Holidays.

AMA 80393
Major USAF
Nov 24, 2006, 10:47 AM
FPV Desert Beta Test Center

Ourside flying

For outside flying how much wind can the 450 be flown in?
Nov 24, 2006, 04:54 PM
Fun Manager
AMCross's Avatar
Hi, publisher, I'll answer to your questions.

Please note the disclaimer immediately below the video. We're still baffled why it plays at acclerated frame rate now when it did not during editing, et al. Not sure what happened, but didn't want to hold the article any longer while Steve tries to figure out what happened.

The music track was laid at my request due to all the background noise at the event. I think it is somewhat of a a heli-reader-biased thing -- i've often had complaints about NOT having music laid on aircraft reviews, but never a complaint about not doing so.

It is not the same heli, it is Scott's own heli and radio system, with the mods stated in the article, as the reviewer's bird wasn't yet ready at the time the video was shot.

Hope you all enjoyed any of the articles which fit your interests this weekend. It was a huge production to pull together more than 20 projects to culminate all this weekend! Happy holidays, everyone!!!

AnnMarie Cross
Fun Manager
Nov 24, 2006, 05:10 PM
Hoverup's Avatar
Thanks for the quick reply AMC. Great group of articles and well timed as we all are thinking what to tell the wife we want for Christmas.
Nov 24, 2006, 05:31 PM
Registered User
Originally Posted by AMCross
The music track was laid at my request due to all the background noise at the event. I think it is somewhat of a a heli-reader-biased thing -- i've often had complaints about NOT having music laid on aircraft reviews, but never a complaint about not doing so.
Actually, I think lots of aircraft flyers also dislike music on videos, I'm one of them. I've read quite a few complaints about music on aircraft videos.

Often, once I realize there is music on an aircraft video that is loud enough to drowned out the sound of the engine I will stop the video. Sometimes it's because I dislike the music, mostly its just because I don't enjoy watching an airplane without hearing the egine.


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