credence
Posts: 2518
Joined: 5/19/2005
From: Brampton,
ON, CANADA
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Building the body.
When starting the body, the first order of business that they tell you to do is to assemble the main auto-rotation gear. However, mine was already assembled from the factory. I went over to check all the screws to make sure they were snug, and went on to the next step.
Auto-rotation gear.
Now we begin the main frame assembly. It essentially consists of the two sides, the bottom base plate, and then various pieces that go inbetween to solidify the entire structure, including bearing blocks, the tail housing, motor mount, etc.
Main frame layout.
Speaking of bearing blocks, I was impressed with the bearing retention system used here on the T-rex 600. The bearing fits snugly inside a small crevice between two halves of the bearing block, and then is pressed together. This is much better than the simple pressure fit system used in alot of helicopters. There is absolutely no way these bearings will ever come out, short of breaking the bearing block it's self. The main shaft is supported by 3 seperate bearings. The top two bearings are the same inner diameter, whereas the very bottom one has a slightly smaller diameter to fit the slight step down on the main shaft for the main gear mount.
Bearing mounting system.
Then we do the usual screw thing to attach the bearing blocks to one side of the frame.
Now i'm going to skip ahead a bit since there really isn't much involved with the base frame assembly other than doing a whole lot of screwing.
Once you've got both sides assembled, you should end up with something that looks like this.
That's basically it for the base frame installation, now we get to installing the tail housing, aswell as accessorizing the main frame with various electronics mounts.
The tail housing is a huge, beefy piece of molded plastic that could probably withstand a bomb blast. Also included in this hardware bag is the tail pulley and tail belt, as they both must be installed at the time you assemble the rear tail housing.
Tail contents.
First we need to get the tail pulley ready. This can be seen below, already assembled from the factory.
Here, you need to use the included metal-to-metal R34 glue to fasten the bearings to either end of the tail pulley shaft as can be seen in the below picture of the completed assembly.
Next it's installed into the tail housing, be sure at this point to also put the tail belt around the pulley, otherwise you won't be able to put it in after the housing is assembled.
Pulley in the tail housing (no belt yet)
After pressing the two halves together with the tail pulley AND the belt inside, we get to the fun part of screwing the whole unit into the main frame. A whopping 12 self-tapping screws is used to hold the tail housing in. Let's just say my hand is rather sore right now.. 
Tail mounted into the main frame.
Next on the list is the main motor mounting plate. This is machined from aluminum and polished to a gleaming silver. One side is flat, while the other has ridges running all along the back. I believe they we're put there to allow the motor breathing holes so as to allow the internal fan air-intake space. Without them, the intake holes would be completely covered and ineffective. Obviously, you'll want to make sure the ridges get installed facing the motor it's self.
Main motor base mounting plate.
Installed in the helicopter
At this time, I also installed the various mounting trays for the electronics at the front and rear, including the battery and gyro mounts. This helicopter is definately well thought out, with plenty of room for all your radio equipment, while keeping the noisy electronic parts away from the sensitive equipment. (Gyro and RX at the back, Motor, battery and ESC up front).
Fully accessorized!
After getting the main frame assembled, we install the elevator and aileron/pitch arms. This is another area where the manual gets everything backwards. This was something that SHOULD have been done without the top bearing block installed (while assembling the two frame halves would be a prudent time to do it). As it is, to install it properly I needed to remove the upper bearing block so I could get my hex driver between the frame to screw in the elevator control arm. Not a deal breaker, but a pain in the ass still, especially since I had semi-set loc-tite on all those bolts. At anyrate, I finally got the thing together. I know alot of people have been replacing the push/pull control arms with metal ones. I personally see no real reason to do this. They're solid, with zero flex in them, and they move cleanly and easily.
Control arms.
Now we come to installing the skids. My kit came with two different skids. The black standard ones, and the white "3D" ones. I'm not sure what exactly it is that makes these skids "3D" though, if you look at the below picture, you'll see that they do have a slightly lower profile.
Since I dig low profile skids, I decided to use the white ones rather than the taller black ones. The skids mount onto the bottom four blocks of the main base plate using a bolt and lock nuts.
Next comes the straight forward process of installing the skids them selves, which are also held in place by grub screws to keep them from shifting (good idea!). I also took the time to install the rubber shock absorbers and the end caps for the skids. Simple, straight forward assembly on the skids.
Finally starting to look like a helicopter!
Moving onto the tail
First things first, you need to install the tail boom. However, it's a good idea to assemble and install the tail servo mount, aswell as the rod guides for the tail pushrod. The servo mount is a nice two section setup, consisting of the servo mount it's self, and then two plastic brackets that clamp to the boom.
Servo mount and brackets.
The brackets clamp on using two bolts. The rod guides simply slide onto the shaft.
Assembled shaft with rod guides and servo mount.
Now that we've got these items attached, we can stick the boom into the body. Don't bother screwing in the front tail housing yet, as you will need to adjust belt tension later on when you install the rear tail housing. Make sure that the right end of the boom is going into this side of the helicopter. The boom has a small notch cut into it that matches up with a notch inside the forward tail housing.
Boom installed on the helicopter
At this point in the manual, Align also says to fasten down the tail rod guides. The method they use for this is rather bizzare. Instead of using a clampable rod guide with screws, they tell you to stick a small piece of tie wrap under the guide to tighten it up against the boom. This doesn't seem like a very effective method to me. I'm sure it works fine, but it just seems...odd. I'm going to see if I can come up with a better method of keeping the rod guides from moving.
They want me to stick tie wraps under this?
With that done, we can move on to assembling the rear tail housing. This is by far the easiest tail i've ever assembled. With only 3 major parts to put together, and only 3 screws at the back and 2 at the front, it was a breeze to put together.
Tail Parts
You start by placing the tail shaft (with gear already installed) into the left half of the tail casing (through the bearing, of course). At this point, you also need to wrap the tail belt around the gear. It's important to make sure you put the correct direction of twist into the tail here. If you twist the belt the wrong way, the tail won't spin in the right direction. If I remember correctly, it's a clockwise twist on the belt. With the belt installed, you can proceed to install the other half of the tail gear.
Tail housing installed.
Next on our list is the tail it's self. This consists of the main hub and blade grips (bearings installed already!) aswell as carbon fiber tail blades (a nice surprise, didn't notice that on the product feature page!).
Tail hub and grips (blades not shown)
Installing the grips is a simple and straight forward process. This is one area in particular where you want to MAKE DOUBLE SURE YOU USE LOC-TITE! This is a high stress, high vibration area. Forget loc-tite here and you'll find your self without a tail blade real quick.
Simple screw each grip into the rotorhub. No washers or anything are nescesary as the hub is built in with the nescesary lip to prevent bearing friction.
Assemebled tail hub.
Now we can install the tail blades into the grips.
Carbon Fiber tail blades and tail hub.
Here you want to make sure you have the blades installed properly. The leading edge of each blade should be facing the same direction as the blade grips connector. See picture below.
Blades installed into the grips.
With the tail hub done, we can move on to the pitch slider. You'll have to forgive me at this point, my camera was running low on batteries so I was spreading out the ammount of pictures I was taking during the build.
The tail pitch slider is, like many of the smaller more complex parts of this helicopter, already assembled for you from the factory. Satisfied that everything was tight, I went about preparing it.
Pitch Slider
The T-rex 600 uses an interesting system for the tail pitch changes. Instead of using ball links as is common with many helicopters, the pitch slider is connected directly to the blade grips using two small arms, which rotate on small brass bushings. This is one thing that I wasn't thrilled about. This is one area where I think bearings rather than bushings really should've been used. The tail certainly moves smooth enough, but not bearing smooth. Perhaps we'll see an after-market part for this.
I should also note out another problem I had during assembly of the pitch slider. In the manual, they tell you it's already assembled from the factory. This is true except for one part, the ball at the bottom of the pitch slider (can be seen in the photo above). This you must install your self, and the ball they provide has treads that are too long. The end result is screwing it in ends up pushing up the plastic underneath the bushing inside the pitch slider, making it stiffer in it's rotation. I ended up pulling out the ball link and taking it to my grinder to shorten it a bit. Once this was done everything was fine. Hopefully it's addressed in future revisions.
Tail assembled and ready to go!
Once again, when assembling this part, you want to make sure the leading edge of the upper blade is facing the back of the helicopter, otherwise you installed your blade grips backwards (I did this the first time around by accident, whoops!). The lock nut for the blade grips should be on the inside of the grip facing the tail case. The tail blades should have their serial number on the outside.
With the tail assembled and ready to go, we can move on to finishing off the boom. The first thing we'll do is assemble the tail braces. These are two carbon fiber rods, aswell as four very nice looking end pieces machined from polished aluminum. Use CA to fix them to either side of the carbon rods. Make sure, of course, that they're lined up with eachother. On one end, they install through the main frame aswell as base plate. On the other, they screw into the horizontal stabalizer.
Tail brace installed
After installing these along with the horizontal stab (they kind of go hand in hand, if you install one you gotta install the other  ) we can install the vertical stabalizer. This also doubles as the rear clamp for the tail case. Two bolts go through it and then through the tail case, with lock nuts on the other end.
(Yes, i'm aware my tail blades are backwards in this picture, please ignore it )
That's it for the tail. The helicopter is almost finished!
Helicopter with completed tail.
At this point, the build is basically finished. It's just a matter of slipping in the rotorhead and installing the main gear.
The main gear gets affixed to the main shaft using a simple bolt with lock nut on the other end.
Main gear installed.
Once the main gear is installed, you can tighten down the upper retaining collet. Here you're going to want to move the main gear up and down untill you get it mating at the right height with the tail pulley gear without the upper main gear grating against the lower tail pulley gear. Once you've got the height just right, tighten down the two grub screws on the collet, making sure to use loc-tite on each.
Main shaft retaining collet.
And finally, here's a picture of the installed rotorhead.
The helicopter is essentially complete now. Naturally, you still need to do all the linkages that will connect the elevator and aileron control arms to the rotorhead, and then the links from the servos to the control arms. As I don't have my servos yet, I haven't done this part of the build, and will leave it untill i've got my electronics installed. It'll make things easier to install if I don't have to dodge around linkages to do it.
I am extremely satisfied with how this helicopter went together. With the few niggling problems aside, it was an absolute joy to assemble. It's also a sight to behold. I really like the color scheme it's got going for it. If it flies even half as good as it looks, i'll be a happy man indeed!
Again, I just want to say how impressed I am with how much thought Align put into the layout of this machine. There is a total of 3(!) different locations that you can use to mount your batteries. The front lower plate. The front upper plate (which also swivels to allow your battery to fit regardless of it's size). It also comes with hook and loop strap holes on either side to allow easy mounting of dual packs (as i'll be flying with) rather than trying to pile them all up at the front. This was a brilliant design decision and I'm extremely happy that i'll be able to side mount my packs rather than forward mount if I need to.
There's a small spot dedicated to the gyro at the top back. A tray at the rear for the receiver battery, and a tray at the bottom for receiver it's self. Align also leaves ample room for motor and servo installation, so you don't need to dodge around things trying to screw stuff in.
I'm going to end the build thread here for now, untill I get my electronics. Then i'll finish it off, and post the initial flight tests and videos (of course!)
High Resolution Images
Click to open any of the below images in a new window.
T-rex 600 1
T-rex 600 2
T-rex 600 3
T-rex 600 4
T-rex 600 5
T-rex 600 6
T-rex 600 7
T-rex 600 8
T-rex 600 9
T-rex 600 10
Comparison Photos vs X-400
T-rex 600 Comparison 1
T-rex 600 Comparison 2
That's all for now folks! If there is any specific images you want to see, let me know and i'll try to get them up 
< Message edited by credence -- 7/30/2006 4:12:04 AM >
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Daniel
True Northern Hobbies, Inc.
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