T-Rex 700L Dominator

Hey there !
It's been a while since the last article... So let's talk about something big this time. something really big. REALLY. The T-REX 700L Dominator, a class 700 (rotor size of about 1.6m, 5kg) helicopter made by Align. If you remember, I started to fly helis with an other Align helicopter, the T-REX 450 Sport V2. We remember beeing very afraid of it when the rotor started to spool up for the first time. Let me be clear, this T700 has NOTHING to do with it.

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So, from a technical point of view, this 700 heli is the most advanced version of the T700E, first 700 electric heli made by align of this side. It features the last upgrades of the frame, BL815H and BL855H brushless servos, the 800MX Align motor, a Castle Creation 120A ESC and the DFC rotor head. The stabilization control is done by the new GPro controller (formerly known as 4GX)

IMG_8212Disassembled DFC head

IMG_8221The Cyclic BL815H brushless servomotors

IMG_8219The huge 800MX Align motor.. A real monster !

The built is really straighforward and you just have to follow the manual :). Beware to threadlock all the metal-to-metal screws and VERIFY it's well locked ! I crashed because a servo screw became loose... 🙁

IMG_8215The frame beeing assembled

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As I said, it comes with the latest "inovations" from Align, so you have two helicoidal gears wich make a really nice sound once in the air 🙂
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IMG_8230the DFC head

IMG_8225Close-up view of the motor and servos

IMG_8232Almost ready to fly here

IMG_8228Tail and servo tail

IMG_8916View of the implentation of components

As I didn't have (still don't) a High Voltage receiver, I had to think a little about electronics in this bird. This is the wiring I used to power the servos with HV source (2S lipo = 8.4V fully charged), and feed the receiver with a safe 5V.
Electro_T700Electronic wiring

The BEC component is actually in the T700L Dominator kit, good point for Align (again) :-D.

IMG_8908Tail assembly details
One word about the CC 120A ESC. When using lower head speed (<1800RPM), the CC tends to get very hot (above 100°C). This can lead to the destruction of the device. I wanted to put a 1500RPM head speed at first but changed my mind after seeing that. 1850RPM works fine for me. As you can see in the next picture, I put the controller on the rear of the frame, which is excellent in terms of heat because we have a giant propeller above it that helps to cool it down 🙂 IMG_8904

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Setting the GPro up is really a piece of cake, we can see Align really cared about the ease of use for this device. It comes with a free software for PC, Android and Iphone users! Note that for the phones, you have to buy a BlueTooth device separately.

IMG_8917GPro unit

As I could expect, it flies REALLY well, and the FBL head is quite amazing at all head speeds I tried (from 1500 to 2100).

Stay tuned ! More posts will come soon.. I hope 😀