T-Rex 450 PRO Build & Review
Written by Ashley Davis Wednesday, 26 August 2009 22:49
450 PROThe items used in this build are all supplied stock in the combo kit except for the AR6200 rx.
The build itself is fully covered in the build video.
Build
The T-Rex 450 PRO comes mostly built but due to not being able to trust anybody else to build my heli's I had to take everything apart and rebuild it myself. I was glad I did this as there were a number of critical screws missing loctite.
Align really needs to take one of two courses of action here, either....
a) build it and loctite everything
b) Supply it as a kit and let us build it ourselves
It takes twice as long to unbuild a heli just because you have to check everything for loctite as the pre-builder is unreliable.
Aside from this issue the build was relatively straight forward. The servos proved a bit of a operation to install as they are so incredibly inaccessible once installed (more on this later). Overall all the CNC and plastic parts are of good quality, the screws are the usual fairly cheap Align items which will strip if you go at them with anything but a perfect hex driver. Any Align heli owner knows the score on screws supplied with Align kits, just expect some to strip.
The new item to the Align 450 class is the torque tube. This is very well executed on the 450 PRO and the smoothness of the mechanism is superb. Let's just hope it doesn't become a big gear stripper like the T-Rex 600 tends to be. Another new approach is the move to a single narrow frame rather the the traditional stacked frame on previous Align 450s. Again this is a welcome change as the SE V2 stacked frame struggled to provide a good rigid base for the mechanics.
Lastly radio install, this also proved to be a real fiddle and getting an AR6200 into the frames proved an interesting challenge. Align really have left virtually no space in the frames for installing equipment.So a bit of a mixed bag on the build side of things, I'm not going to go into huge detail in the text here as the build videos provide great detail on building the 450 PRO.
The kit also comes with new style tail blades which are quite long and slim, certainly different to previous Align offerings. Also this super combo kit comes with the Align GP750 gyro, which just tapes onto the provided place at the back of the frames.
The head on the 450 PRO is really a shrunk T-Rex 700N head, interestingly most of the links are fixed length with the only adjustable rods being the ones that go from swashplate to the upper mixers. This means that the head has good symmetry and errors don't creep into the head system due to inconsistent rod lengths. The head has no adjustability/programmability in it, so you are pretty much stuck with the flybar input, mixing ratios etc which is a bit of a let down when models like the Outrage G5 provide so much tuneability these days.
SE V2 Differences
The 450 PRO is significantly different to the 450 SE V2, in fact I found very little parts commonality, even the main shaft is different. SE V2 owners can pretty much forget buying a few upgrades to make a 450 PRO, it's a whole new helicopter basically. Obviously this can be viewed two ways, personally I like the level of difference as it means it is different enough that hopefully it will provide a different flying experience to the familiar SE V2.
Flight Testing
The T-Rex 450 Pro has the new align motor which is 3700 KV and uses a 13 tooth pinion. This gives an extremely fast head speed of around 3400 rpm which equates into quite a powerful performance. The question is whether this powerful performance comes with a level of flight accuracy to go with it. This is where this new model surprised me most. I was expecting that the tail would be a little bit more crisp but overall I was expecting a fairly typical set of 450 flight characteristics. I was wrong this model I believe has better flight characteristics than the T-Rex 500.
This is where things become a little bit difficult to quantify. Whilst this new model does not have the bigger feel or stability of its larger brother it definitely has a more planted and accurate feel to it. It tracks extremely well through large manoeuvres but also has the accuracy and precision to be flown extremely low through hardcore stick banging 3D. This makes it a pleasure to fly but also a superb practice machine for learning new manoeuvres.
The collective is nice and crisp and very responsive but this is coupled to a supremely accurate cyclic response. However, I don't want to overdo the capabilities of this machine in the review. It is still a 450 and therefore it inherits typical 450 characteristics such as being much more susceptible to wind and also not being as stable as larger machines in the hover. It also is very typical of the 450 class in terms of being very fast in forward flight and therefore due to its size it gets very small very quickly in a circuit.
This review is looking at the super combo and therefore it would be wrong not to talk about the servos or the gyro that come with the kit. Let's start by talking about the cyclic servos. These are full digital servos (DS410) which have very good torque as well as being quite fast when run on 6 V supply. They are also very accurate and contribute to the impeccable flight characteristics already mentioned. The tail servo is a larger mini sized servo and boasts very good speed characteristics. In flight I have had no complaints regarding the cyclic capabilities of the machine but I have experienced some issues of tail blowout which equally could be the gyro or potentially the tail servo. Personally at this point I am holding the gyro responsible for these blowouts.
The GP 750 gyro provides a very competent performance. This is only let down by the occasional blowout, particularly when flying manoeuvres which bog the head down. I was pleasantly surprised by the gyro and that for the most part it provides a more than adequate level of performance. I will be changing the gyro to my usual CSM 720 gyro shortly as whilst the GP 750 does a good job it doesn't have as good tail hold or anywhere near the Piro consistency of the CSM 720.
Carbon blades
The carbon blades supplied with the kit are 325mm in length and provide a very good flight performance. Cyclics are quick and the collective performance is crisp and accurate. All in all the stock supplied blades work extremely well and I can't come up with a good argument for either not using them or replacing them with another brand blade.
Pros
Strong & flex free frames
Great flying characteristics
Perfect 120 degree servo layout
Super smooth torque tube drive
Good power from the new Align motor
Cons
Pitch slider ball and cup is pretty outdated and sloppy compared to more modern designs
Building and working on the heli is difficult due to the design, particulalry servo maintenance which is awful
Very little parts commonality or upgrade path from the 450 SE V2
Conclusion
The T-Rex 450 Pro is a true evolution for Align from the old but competent SE V2 to this stunning new PRO model. My opinion is that this is the best heli Align have released to date, it has virtually no issues that need fixing to make it a reliable or trustworthy heli to fly. Add to this impeccable flight characteristics, a strong motor, decent servos and a capable gyro and it's hard to ignore what a great combo package this is.
In my opinion the best 325mm bladed 450 on the market today.......and that really does include the Furion in that assesment as I'm taking into account not only flight manners but cost of ownership and maintenance.
I've deliberately said 325mm bladed as I believe the 350mm bladed 450s actually represent a different and bigger class of helicopter. I know heated debate has occured around 350 bladed heli's and how they compare to the PRO. For the moment I'm treating them as a different class of heli, 450+ perhaps. For this reason I have not looked at comparing the PRO to the Rave or G5. If Align did want to compete in this area then one things for sure, it will need to shy away from traditional 450 3S power systems.
Final thought .... buy a 450 PRO if you like 450 sized helis, you really won't regret it.
( 42 Votes )
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