T-Rex 450 SE V2 Build & Review

450 SE V2
The items used in this build are as follows:

Align T-Rex 450 SE V2
Align 430XL motor
Align 2100 18C lipo
Spektrum 6100 rx
Futaba 401 gyro
Hitec HS-56 Servos
Futaba 3154 tail servo

I will go through the build a step at a time. I have not followed the manual as the SE V2 comes mostly assembled. I built the model in the most logical manner given what is already assembled.

Build

When you open the box there does appear to be quite a lot of different bags of bits and pieces and the initial impression is that there is quite a lot to do. In reality most of the complex building has been done for you. The rotor head comes preassembled, the upper and lower frames come preassembled and the tail gearbox comes preassembled. Essentially building the T-Rex is a matter of connecting the upper frames to the lower frames, installing the tail gearbox onto the boom, installing the boom onto the main frames and then inserting the rotor head through the main shaft bearings, through the main gear and securing in place.

However, I would thoroughly recommend that any screws that are going into metal should be removed and some loctite applied and then replaced. Specifically the blade grip screws that go into the feathering spindle had no loctite on them at all. I already know of one owner who has had his blades fly off due to this problem.

My approach to the build was to assemble the main frames first and then bolt everything else onto them.

As previously mentioned the upper and lower main frames have already been assembled. The kit contains a bag with all of the screws and the motor mount in it, this is the one you need to bolt the main frames together. Remember to use loctite on all of the screws going into metal and do not use loctite on screws going into plastic as the loctite will soften the plastic.

The build of the main frames also includes installation of the anti rotation bracket as well as installing the extended battery tray. The pictures below show the build up of the main frames and the associated parts.

Having built the main frames I decided to install the undercarriage as this would give me a nice stable platform to work from for the rest of the build. Don't forget to use a little bit of CA to hold the skids stoppers in place.

The next task was to install all of the tail boom accessories onto the tail boom. This includes the servo mounts as well as the plastic guides for the tail pushrod. The pictures below show these installed and the boom installed into the main frames. However, at this point the boom should not be installed into the main frames as the tail gearbox needs to be fitted first.

Strangely enough the next item is the installation of the tail gearbox onto the tail boom. The tail gearbox has a single screw which clamps it onto the boom. This should be slackened and the belt unwound and threaded through the boom. I use a piece of string tied to the belt to pull it through the boom. It's virtually impossible to either dangle or push the belt through the boom on it's own. Another method for getting the belt through the boom is to use a coathanger that has been bent and unwound and made into a little hook. This is then pushed through the boom, hooked onto the belt and then the belt pulled back through the boom.

Once the belt is through the boom the tail gearbox clamp screw can be tightened. This is just to hold it in place for now. It is important at this stage to look down the boom and get the belt and tangled and without any twists. Once this is accomplished the boom can be inserted into the main frames. The belt is then given a quarter counter clockwise twist onto the tail drive pulley. Pull the tail boom back to tighten the belt slightly and then do up the tail boom clamp screws temporarily to just hold it in place.

The next two tasks are very quick and easy to accomplish. Firstly the main gear should be inserted into the frames and lined up ready for the main shaft. Secondly the preassembled rotor head and main shaft should be inserted down through the main shaft bearings, through the main gear and then secured in place using the provided bolt and nyloc nut.

At this point check that the tail belt is installed correctly by rotating the rotor head clockwise when viewed from above. The tail rotor should rotate anticlockwise when viewed from the right-hand side of the machine. If the tail rotor is rotating the wrong direction then you need to remove the existing 90° twist and add a 90° twist the opposite way.

At this point the main elements of the build and have been completed and now it's a case of installing various bits and pieces to complete the machine. The first of these are the horizontal and vertical fins, tail boom struts and the tail blades. Having fitted these without doing up any of the screws too tightly it is time to line up all of the components of the tail boom. What I mean by this is getting the tail gearbox aligned so that the tail shaft is horizontal, making sure the vertical fin is indeed vertical and that the horizontal stabiliser is nicely lined up and at 90° to the vertical fin. Once all this is done all the various screws can be tightened up and, where appropriate, loctite applied . I recommend taking all of the screws out of the tail gearbox one at a time and applying loctite.

The previous section was about finishing off the tail. The next section is about finishing the rotor head. The flybar carrier, flybar and paddles need to be installed on to the preassembled rotor head. Also the main shaft locking ring needs to be tightened into place ensuring that there is no vertical play in the main shaft. The flybar can optionally be fitted with the supplied flybar weights for beginners. Advanced pilots will want to leave these in their packet. The flybar should be centered and locked into place, the paddles can then be installed such that they are equidistant from the flybar cradle. The paddles also need to be lined up so that they are in line with the flybar cradle. In other words if the flybar cradle is horizontal then the paddles should be horizontal as well.

All of the head linkages can be built at this point and installed onto the preassembled rotor head. I found the measurements for the control linkages to be absolutely correct in order to get + / -10° pitch. In order to set the linkages at the correct length I used a digital vernier. Once you have installed all of the linkages onto the preassembled head you should be left with three linkages of different lengths. These are the linkages that fit onto your servos and connect to the swashplate. Put them somewhere safe for now.

The kit comes supplied with the new Align 430XL brushless motor. This should be fitted with the 13 tooth pinion for 3-D fliers or the 12 tooth pinion for beginners. I filed a flat on my motor shaft using a Dremel so that the grub screw would stop the pinion from rotating on the shaft. Once the pinion is installed the motor can be bolted into the motor mount using the screws and washers supplied. Don't forget to fit the motor with the supplied bullet connectors before installing it into your main frames.

The kit also comes with the Align 6 V electronic speed controller. This should be fitted with the appropriate bullet connectors before being secured with double sided foam tape onto the main frames. The instructions explicitly state that you should not secure the speed controller to the main frames using cable ties and that this will invalidate your warranty. Also it is worth noting that this particular speed controller in the past has had the heat sink glued to the plastic shrink wrap rather than the circuit board itself. This is not the case with this new offering and the heat sink has been installed correctly onto the circuit board.

The last task is to install your chosen servos, receiver and gyro. Some things to note are that the main frames are not drilled to accept a servo with four mounting screws (like the HS 56 and HS 65). I therefore modified my servos so that they could be fitted using a single centre screw. This just involved drilling a small hole between the two holes already drilled into the servo for mounting screws.

I fitted a 401 gyro and there is now a nice smooth surface on the underside of the boom clamp. The 401 can be secured to this using double sided foam tape (supplied with the 401 gyro). I chose to fit a Spektrum AR6100 receiver on the front battery tray as I will be using my 2.4 GHz DX7 transmitter with this model.

Below are some pictures of the completed model with the canopy removed.

Below are some static shots of the completed model. I have included some close-ups as they come out better in natural daylight than the shots taken on the bench.

That completes the build information. I have deliberately kept it fairly short as the majority of the kit is already built and it is just a case of bolting together the fairly large and preassembled components.

SE V2 Differences

What is different about this new SE version 2 and why should we be excited about it?

Initially let's talk about some of the items on this model that have been released recently but are not included in the current SE version 1 kit. The main items are the main gear which includes the easily removable one-way bearing. Also this kit has the latest tail gearbox and tail pitch slider mechanism. This new gearbox and slider is silky smooth in operation and should provide a very nice and wag free tail. The kit also includes Align's latest 6 V 35 amp electronic brushless speed controller. Additionally Align have included in the kit their latest lipo which is specifed as 3S 2100mah 22C.

On top of this there are several items which are brand new. The kit includes some very nice carbon blades, a fibreglass pre-painted canopy. The motor is a brand new 430XL which is designed to deliver even more power than the previous 430L. Lastly the rotor head, specifically the head block and blade grips have been completely redesigned. These new grips are ball raced and the feathering spindle is 4 mm instead of 3 mm. Putting thrust races in the rotor head should provide a much much smoother collective pitch response from the helicopter.

Not forgetting Align also include some proper and very nicely finished carbon blades with this kit.

So essentially what Align have done is consolidate all of their best upgrades into their top of the range kit and then on top of that introduced a new rotor head and motor. You will also notice from the photographs that the anodising is now a darker blue making the SE V2 instantly recognisable.

Upgrading an SE V1

If I was to upgrade the previous SE to make it as close as possible to this new model then I think my chosen upgrades would be the head block and blade grips, main gear and tail pitch slider. These items are the main ones that improve the flight characteristics of the new model.

Flight Testing

This is always my favourite bit. How does this new model perform in comparison to the SE version 1?

The first thing I noticed when spooling up was how quiet but also how smooth the new gear train runs. The machine is now quieter overall, much smoother running and sounds much happier for it. It is almost turbine like in the way it runs and reminded me of the first time I spooled up a T-Rex 600.

The second thing I noticed was that with a 13 tooth pinion the head speed is very quick, definitely over 3000 RPM. However, the machine runs so smoothly that it doesn't sound like it's going as fast. Easing up into the hover again the feeling of smoothness continues to dominate. This is one very sweet running machine.

I spent a little while hovering and although I didn't fit the collar (flybar) weights I was quite surprised at just how docile and solid the machine felt in the hover. With collar weights I imagine it would be rock solid. The next few flights were spent sorting out the tail rotor as I seem to be burning out 3154 servos as quickly as I could fit them. I will be doing the 3154 review shortly but suffice to say these things don't last long if you run them on 6 V.

Eventually I fitted the trusty 9650 and all my tail problems were solved. Now I could really open her up and see what she could do. However, before I do that I should mention that the Align pack supplied in the kit appears to have a very good turn of power and voltage hold. It remains to be seen how many cycles I can get from it.

So it was time to test this model out with some 3-D. I flicked into idle up and was satisfied to hear an increase in head speed of a couple of hundred RPM. Slamming the stick open the 430XL climbs like a rocket, this is definitely the most gutsy motor Align have produced thus far. Although, I should temper this by saying that it does appear to be pulling quite a significant number of amps in order to deliver this power. I will be doing a full motor test very shortly on this motor and some other new motors.Anyhow, back to the 3-D flight. One thing that is very noticeable is that the collective pitch is now much more like a big machine than a micro helicopter. By this I mean that I was able to do sustained manoeuvres like side on tic tocs and be able to accurately feel my way through the manoeuvre. This is the main difference in flight and it should not be underestimated. I feel much more confident flying the SE V2 because the collective pitch is so much more accurate and controlled. You can bring the machine lower and perform more daring moves without worrying about whether the collective pitch is suddenly going to bite you and the model fly off unexpectedly (as often happened with the previous SE). The thrust races definitely deliver a much more controlled performance. The cyclic pitch is much the same as the previous model but again things feel smoother because the machine runs smoother overall. The only complaint I would make is that the damping does feel a little soft and could do with hardening a bit. I am aware that some larger spacers can be used on the head to squash the dampers more which increases the hardness of the dampening. I shall be making this modification.

The tail on the SE V2 is exceptionally smooth running and certainly the best gearbox and slider produced by Align to date. This does translate into a more trustworthy tail response. I am still working on getting the tail exactly how I would like it but it is already better than I have had on previous models.

Some 401 gyro setup info when using the 9650:
Use the inner most hole on the round servo horn
Gain : 46%-50%
Delay: 25%

You will have noticed the use of the word "smooth" a great deal in this flight test. This is the overwhelming feeling you get when flying the SE V2. Gone are the days of sticky collective pitch and main gears that didn't run true.

Overall I am very impressed with the new SE V2 and I shall be selectively upgrading parts on my old machines to get them to run as smoothly as the new one.

Below are some pictures of the SE V2 in-flight. I apologise that many of them are similar but my cameraman for the day was my nine-year-old son and he wasn't having much luck taking photos of the SE V2 whilst I was throwing it around. All things considered I think he did a great job.

Carbon blades

This new model also comes with a very nice set of carbon blades. These are actually the best blades Align have ever produced. They respond very nicely, autorotation performance is reasonable and they feel quite crisp on their collective response. They also don't bog the new 430XL motor too much allowing the machine to perform.

Pros

All the latest upgrades
Comes with motor, ESC and Lipo
Partially assembled
Fiberglass pre-painted canopy
Superb flight characteristics
Powerful motor for 3D

Cons

Loctite not applied to all the necessary screws during pre-assembly
Tail boom clamp still doesn't stop the boom from being pulled in causing the tail belt to go slack

Conclusion

The new T-Rex 450 SE V2 is the most comprehensive kit that Align have produced to date. It includes everything you need to get airborne apart from servos, gyro and a receiver. The provided motor has plenty of power for some quite exciting 3-D and the ESC runs at 6 V giving your servos a bit of a speed boost. Added to this they have provided a pretty decent lipo. The upgrades in the kit from the old SE V1 make a real difference to the flight characteristics and a beautiful fibreglass prepainted canopy is included.

Align really have thought of everything this time. This is a superb kit with great flying characteristics (I'd go as far as saying it is the best micro I've ever flown). It looks fantastic and really will do hard 3-D straight out of the box. If you are in the market for a new micro helicopter this is absolutely the one to go for.

 

 


( 57 Votes )


Add this page to your favorite Social Bookmarking websites
Digg! Google! Live! Facebook! MySpace! Twitter! TwitThis Joomla Free PHP

RSS Feeds

HeliTuning - Blog