Align CNC Head

The following is a product review of the Align full metal head, including rotor hub, washout base and arms, mixer arms, flybar hub and cradle.

A very valid question to ask at this point is why this review is covering all of the upgrade head components in one review rather than separately? The answer to this is relatively straightforward.
Over the past months I have attempted to review these parts separately as they were released onto the market. The release of the XL T-Rex caused a problem with these reviews.The newly released machine had an all-new head and mixers and the benefits of upgrading to CNC parts in small increments was extremely hard to quantify for each individual upgrade. The XL was a step change in quality from the original T-Rex and I therefore decided that for me to quantify the differences I would need to review the whole CNC head and make the comparison with an all plastic stock unit.

For those who are currently running the original T-Rex any one of these upgrades will provide an improvement in flight performance which would be noticeable for a beginner as well as an expert. However, if you are an owner of the original T-Rex I would recommend upgrading to the plastic head and mixers of the XL T-Rex and save yourself some money. Whilst at the same time significantly improving the flight characteristics of your machine. The benefits for an XL T-Rex owner are discussed in the conclusion.

With these questions and recommendations complete let's move onto the review itself by quantifying exactly what components are being reviewed. The pictures below show the separate packages covered by this article.

Let's look at and talk about these various upgrade parts one at a time and then look at how they perform when working altogether. Just before doing that it is worth saying a few words about the quality of these components. They come in an anodised blue and the metal appears to be of the higher aircraft grade aluminium which doesn't bend easily. All of the featured components can be installed as drop-in replacement for the original stock items. The mixer arms and washout are fully ball raced as is the flybar hub with the flybar itself running through ball races. The blade grips are a three bearing design but I was slightly disappointed to only see radial ball races in the blade grips and no thrust races. Having done some load calculations it is likely that the ball races in the blade grips may start to freeze with head speed of 3000 rpm or more. None of these upgrade parts were either difficult to assemble or problematical to install. All of them function correctly without modification after installation. When assembling these parts take care to use loctite on any metal to metal screw fixing, without this vibration will work screws loose. Any screw coming loose in the head assembly will result in a crash.

Flybar hub

This is a one-piece unit which basically allows the flybar to run inside bearings rather than a plastic bushing. The bearings in the hub have a smaller internal diameter than the original T-Rex flybar and therefore this unit comes with a new flybar that does fit through these bearings. This smaller diameter flybar can also be bought separately. Once assembled the flybar paddles move extremely freely offering very little resistance to movement. This should allow for finer cyclic control and less strain on the cyclic servos. It is to the outside of this flybar hub that the upgrade mixer arms are attached.

Washout arms and mixer arms

The washout arms and mixer arms come as one upgrade to replace both sets of the plastic mixer arms. They come with their own bearings installed. The washout arms need the plastic connectors that go down to the swashplate installed onto them before fitting to the washout hub. The main benefit of these parts is that they are not flexible like the original plastic arms and they also have upgraded bearings. Additionally there is no friction between the CNC mixer arm and the hub. This allows for very free movement and again should improve fine control for both collective and cyclic.

Flybar cradle

This is a CNC exact copy of the T-Rex XL flybar cradle, given the rigidity of the original cradle I can't see any performance benefit in this particular part and it's addition to the all metal head in my view is aesthetic.

Rotor hub and washout base

Again these are near identical CNC copies of the original plastic parts, however, unlike the flybar cradle the rigidity and hardness of these parts does offer performance benefit. Additionally the precise moulding of these parts does allow for a very precise match between the anti rotation pin on the rotor hub and the brass bushed washout base. On the plastic head, alignment of these pins can be problematical when trying to match to a metal washout base.

Blades grips

The blade grips are not identical in anyway to the original T-Rex plastic blade grips, either on the original 450X or the new XL. These new blade grips feature extra bearings over the stock blade grips and of course their rigidity helps greatly in areas of blade tracking both whilst in the hover and also when executing high g-force 3-D. Which can make for much smoother flight characteristics and elimination of blade flap to some extent. The blade grips feature radial bearings throughout and therefore I would not want to push these blade grips beyond 3000 RPM as there is a possibility of the bearings starting to freeze under load. Ideally a performance blade grip should include a thrust race which will cope much better with the forces acting upon it when subjected to the high head speeds often utilised by 3-D pilots.

Below are some individual pictures of the parts and some assembly pictures showing the whole head.

Build quality

This is always a factor directly related to the cost of the component. Align upgrade parts are typically cheaper than other after market parts and this is rarely reflected in the quality of the CNC machining. These upgrades are no exception to this and I found the quality perfectly acceptable. Added to this the parts are very nicely anodised in the usual Align light blue. As previously mentioned I would have preferred to have seen a thrust race in the blade grips but aside from this the supplied bearings are of sufficient quality. All of these parts are machined to fit perfectly together and there should be no issues with misalignment as can be found on some of the stock plastic parts.

Flight characteristics

Okay, having given a brief overview of the various components the real question is what impact do these parts have on the overall flight characteristics of a T-Rex. This is an interesting debate. I believe that if sufficient time is invested in making sure that the original T-Rex head and control components can move smoothly and freely then that T-Rex is capable of hovering just as nicely as one of the later XL T-Rex. However, once you push into sports flying and then onto 3-D the differences in quality start to become apparent. The same is true when looking at the stock plastic XL head in comparison to this CNC head. For hovering and sports flying you may be hard pressed to tell much difference between this upgraded head and the original stock plastic one.

The differences become apparent once you move into 3-D. Firstly the CNC head is far more capable of holding carbon blades in track during violent 3-D moves. This comes across in the behaviour of the helicopter as a much smoother machine to fly 3-D. As an example when performing a basic forward flip the CNC head is more likely to complete the flip without deviating to the left or right. Additionally, it is possible to run higher head speed and still have the blades track perfectly. This was best proved using a set of Align carbon blades that I know do not track well when fitted to a plastic stock head. They were significantly better on the CNC head.

One other notable improvement was that in high collective manoeuvres (such as tic-tocs) the overall collective response was more crisp than when using the stock plastic head.

Overall conclusion

As always Align have produced some very nice upgrades for the head components of their T-Rex and have very much set the standard for other aftermarket manufacturers (who may charge more for their parts than Align). Align are definitely making the upgrade market a very competitive place.

The question is whether the expense of an all metal CNC head and components is worth the investment given the level of benefit that it may offer. In this regard I would have difficulty recommending this level of upgrade for anyone who is not capable of 3-D flight. Whilst these upgrades do definitely improve the flight characteristics of the T-Rex, beginner or sport fliers would not push the machine hard enough to exploit the potential of these upgrades or reap the benefits.

This of course doesn't take into account that the prospective buyer may be upgrading because they like the look of these parts rather than needing the performance benefit they may offer. Many upgrade items such as this are bought as much for looks as they are for perfromance.

For the ardent 3-D flyer it is a different argument. Personally I like my machine to be as predictable as possible when being pushed through 3-D manoeuvres. This is where these upgrades offer the most benefit. After fitting these upgrade parts I feel much more confident that my T-Rex will go where I point it during a 3-D maneuver rather than keeping me on my toes wondering if it is going to do something unexpected. This inspires confidence and I have found that my own 3-D repertoire with the T-Rex has expanded closer to what I can do with a larger nitro machine as a result.

The decision to buy is very much a matter of personal choice. The stock XL T-Rex is very capable of performing as a 3-D machine without upgrades. These upgrades do not make the T-Rex any more capable. What they do provide is a more locked in 3-D performance. The personal choice is how highly you value the confidence this will give you in your machine over the dent it will place in your wallet. For me it was a price worth paying as I purchased every one of the components reviewed here rather than them being supplied as review items. The extra confidence they have inspired was worth the financial outlay. Of course this equation may not balance for everyone.

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Performance

Number of ratings: 31

Rating: 4.58