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T-Rex 700 Scale Hughes MD500 Build 28Jul12

Posted by tanker in Scale Helis, TRex.
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MD500

MD500 fuselage with T-Rex700E mechanics

With the SAB Goblin 700 now becoming our performance heli combined with the fun we’ve had with the Align Cobra we decided to convert our Align T-Rex 700 into a scale machine as well. Unlike the Cobra we wanted to get a bit of performance out of it and not fly it strictly scale. We chose the Hughes MD500 fuselage from RC Aerodyne. The three things we like most about this fuselage is its looks — it is certainly easy to see! — its size and its ease of installation.

Build/Installation

The fuselage shipped quickly and without incident. Installing our existing T-Rex 700 into the fuselage turned out to be a bit more difficult than we anticipated but in general it was quite easy especially compared to how other scale builds could be. Unlike the Cobra it required absolutely no modifications to the stock T-Rex 700 other than removing the tail boom supports, fins, and landing gear. Before starting the install we updated the stock Align 3G flybarless system to the latest V3.0 firmware and test flew it. We also prepped the Hughes fuselage by painting the inside gray just because we thought it looked better than the white fiberglass. We also beefed up the fuselage with extra epoxy on the plywood and fiberglass joins and also reinforced the main plywood former with carbon fiber stock. We then attached the gear to the fuselage per the instructions.

MD500 nose off

The nose comes off for easy access to the mechanics. Test fit, test fit, test fit before gluing the tail. Stock T-Rex 700E mechanics with only the gear and tail boom supports and fins removed.

Installing the mechanics into the fuselage is fairly straightforward. Basically you remove the tail case from the 700 and then simply insert it into the fuselage. The tricky part is that the fuselage is actually designed for the T-Rex700N. The E is shorter so we had to add about a 1/2 inch of additional wood risers on top of the full set of included risers to get the proper height. We went through multiple test fittings and had to cut the top cross former to clear the ESC. We epoxied in a new, stronger, former. More test fitting showed the rear ball link on the swash hit the fuselage so we had to grind out a small gap for clearance. We also realized that the fuselage was slightly tweaked and it was not possible to get the fuselage perfectly square with the mechanics. We concentrated on getting the head centered and the tail centered and then did the best we could with the rest of the alignment. We were also careful to ensure the tail case had enough clearance. It turns out the mechanics are not straight in the fuselage (thankfully it turns out it doesn’t matter) and are off centerline in the front by about 1/4 of an inch. After all of this prep work we finally screwed the mechanics down to the plywood and added some extra screws for good measure.

All that was remaining was to glue on the tail boom cone. Further test fitting showed that the included slot in the tail tube was not in the correct spot so we expanded the slot (lengthening it about two inches) and taped off the unneeded gap. We then glued the tail cone being careful to keep it square. Finally we reattached the tail case and screwed on the vertical stab keeping it vertical.

MD500 compared to 700

The new MD500 compared to the original T-Rex 700E canopy. As you can see it is a bit larger!

The fuselage ships with plastic windows that you need to cut out and glue inside the doors. We decided to keep them off for the test flights. The doors are hinged and the doors latch closed. Both seem a bit fragile so we taped them shut with Blendurm tape. The windowless doors are plenty big enough to allow access for battery arming without the need to open the doors at all. Finally we also added two additional metal clips to reinforce the two screws used to attach the nose.

Flying

For our first test flight we were careful to check center of gravity. The batteries needed to be a couple inches further forward than the stock T-Rex 700 but this was not an issue. We then screwed the nose on and clipped it. Spool up was uneventful and the heli lifted off without issue. It was immediately apparent that the heli was going to fly without any problems. It of course feels a bit heavier in the air but surprisingly not dramatically so. After one flight of just hovering around we landed and checked everything. All seemed well so  we prepared for another flight. The instructions warn of doing aerobatics with the fuselage and especially of boom strikes. Without the tail boom supports there could be a bit more tail flex but the fiberglass tail tube is fairly rigid. Well there was no better way to find out than to just try it! We did some basic forward flight and noticed that the size of the heli gets it blown around a tad in high winds but the 3G seemed to handle this just fine. Forward flight characteristics are normal with no odd pitching or other issues. Tracking seemed fine so the slight alignment issue with the mechanics and the fuselage do not seem to make any difference in flight. After getting comfortable we did a wide loop without a problem then did a series of rolls and forward flips (we figured back flips might be pushing our luck). Inverted flight was no problem but it sure does look weird. We then landed.

Careful post flight inspection showed no signs of cracking or stress on the fuselage. We now have six aerobatic flights on the fuselage without any issues or signs of stress. We have decided to keep the windows off to improve cooling and allow easy access to the batteries. In the air you can’t tell the difference. We are getting about 6:30 of aerobatic flight time. You certainly cannot 3D the heli but basic aerobatics and aggressive flight seem to be no problem. The key is probably to simply keep all maneuvers smooth. The heli has a great presence on the ground and in the air and the fuselage is very easy to see in the sky. All in all we could not be happier with it.

Align AH-1 Scale Cobra Fuselage — Build 23Apr12

Posted by tanker in Advanced, Beginner, Scale Helis, TRex.
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Cobra Frames

Align T-Rex 500 Cobra frames (underneath) compared against the stock T-Rex 500 frames (on top).

The Align AH-1 Scale Cobra Fuselage kit is a very nice and complete package. The fuselage is about 95% complete and all the builder has to do is swap frames, add-on the raised tail component and then insert the assembly into the fuselage. The fuselage itself comes fully painted and just needs decals applied and a few minor bits.

Cobra frame cuts

Red lines indicated where the frames were cut to accommodate the scale cockpit. Easiest way to do this is with a cutting wheel on a roto-tool.

Of course the reality of any build never ends up being quite so simple even with a complete package. The frame swap was rather straightforward and if you do one side at a time it goes quite easily with minimum of hassle and it will not mess up your mechanical setup. The main difference between the stock and Cobra frames is that the Cobra frames drop the tail to the bottom. The difficulty comes much later unfortunately. The Cobra comes with a nice scale cockpit that looks very nice and just slides into the canopy. If you want to use this cockpit then the frames are going to need to be cut. The normal battery position of the T-Rex is not going to work with the scale cockpit and you will need to cut about 1/4″ of the frame off above the battery tray. Why Align did not adjust this after going through all the trouble of creating new frames is a complete mystery. It is an easy cut to make but not one you would discover until you first test fitted the mechanics into the fuselage. If you do not wish to use the scale cockpit then life is easier and you can use the new frames as they are.

Coming soon: Building the tail, flight test, installing the mechanics, balance issues, and more.

SAB Goblin — First Look 30Mar12

Posted by tanker in Advanced, General Heli, Scale Helis, TRex.
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Align Cobra vs SAB Goblin Tail Boom

Align Cobra vs SAB Goblin Tail Boom

We got our SAB Goblin. Here is an image that speaks for itself!

More on both the Cobra and Goblin soon.

Align AH-1 Cobra Scale Fuselage 28Feb12

Posted by tanker in Advanced, General Heli, Reviews, Scale Helis, TRex.
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Align AH-1 CobraWe picked up the new Align AH-1 Cobra Scale Fuselage for the T-Rex 500. The fuselage is fully painted and comes with a detailed cockpit and the necessary components to modify a stock T-Rex 500 helicopter to work in the scale fuselage. The fuselage and cockpit are extremely high quality and well detailed. We have finished the conversion and are about to test fly the mechanics and then complete the build. We will have more details on the project soon.

Below are a few pictures to give you a sense of the kit and its size.

Align 3G Update 26Jun11

Posted by tanker in Advanced, Beginner, TRex.
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Align 3GThe new T-Rex 600E Pro ships with the all new Align 3GX flybarless system but for owners of the previous 3G unit Align recently released version 3.0 of the firmware. You will need the USB updater to apply it. You can download the new firmware along with instructions and a setup video from Align’s site. We have not had a chance to load it ourselves yet so cannot comment directly on any changes but it supposedly allows for finer adjustments, saving and sharing of settings, and improved pirouette.

Well the not so mysterious disappearance of the T-Rex 550 flybarless kit is solved. Align released a new 550 v2 3GX kit. This is the same 550E kit as before repackaged with the new 3GX unit and the new Align flybarless head. If you are getting, or have, a 550 don’t forget to check out KDE’s 550 upgrades. They have a number of nice choices. We especially like the metal Tail Servo Mount.

[Updated: 27JUL11]

Align T-Rex 600E Pro — Coming Soon! 13May11

Posted by tanker in Advanced, Beginner, News, TRex.
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T-Rex 600E ProCertainly the big news this month is the official announcement of Align’s newest version of the T-Rex 600E. The all new 600E Pro is a completely new design including a top mount motor, under slung 10-12S power, and more. Also announced is the next generation of the Align 3G flybarless unit the new 3GX.

T-Rex 600E Pro MotorThe T-Rex 600E Pro will ship in both flybar and flybarless combo sets that include motor and servos and even a Castle ESC.

Here is a video of the heli in action.

We suspect we will see some new packaging of the other T-Rex helis with the new 3GX unit as well as Align’s new flybarless head design.

Specifications (T-REX 600E PRO):

  • Height: 353mm
  • Width: 210mm
  • Main Blade Length: 600mm
  • Main Rotor Diameter: 1347mm (53.03 in)
  • Tail Rotor Diameter: 260mm
  • Motor Drive Gear:13T
  • Main Drive Gear:112T
  • Autorotation Tail Drive Gear: 131T
  • Tail Drive Gear: 34T
  • Drive Gear Ratio: 1:8.61:3.85
  • Weight(With Motor): 2350g (5.18 lbs)

SmackTalk RC 23Jan11

Posted by tanker in Advanced, Beginner, General Heli, News, Reviews, TRex.
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SmackTalk RCIf you have not checked out SmackTalk RC yet you should. Bert and Bobby have been producing some very useful and entertaining shows. They are only a few dollars a pop and they provide multiple resolutions and formats so you can watch them on your device of choice.

If you are wondering where to start we found their Learning 3D episodes very useful as well as Episode #10 – Going Flybarless! but you can’t really go wrong with any of them.

RealFlight G5.5 28Nov10

Posted by tanker in Advanced, Beginner, General Heli, News, Products, TRex.
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RealFlight G5.5

We finally got around to picking up RealFlight G5.5. It is a nice improvement on the last versions of RealFlight. The flight dynamics seem better than in G4/4.5 and the new depth of field feature is nice (when turned down to medium). For heli pilots it includes a number of scale helis. Expansion Pack 7 includes the Curtiss Youngblood Rave 450 model (but not the new ENV). Still no new Align helis (especially the 550, 600 or 700) but the T-Rex 500 is in Expansion Pack 5.

There is an upgrade version available for previous owners and we got it running on 64bit Windows 7 with a minimum of fuss. We did have a couple of startup dll errors where we had to reset to defaults to get it to load but then all was well.

T-Rex 700E — Review 19Aug10

Posted by tanker in Advanced, Beginner, Products, Reviews, TRex.
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T-Rex 700E 3G Combo

T-Rex 700E 3G Combo

The T-Rex 700E is Align’s long awaited 700-class electric helicopter. Currently you can buy the heli in two forms. First is the traditional 700E flybar version that also includes the 700M motor and 105mm carbon fiber tail blades. The other option is the 700E 3G combo kit that includes not just the 700M motor and 105mm carbon fiber tail blades but also 690mm carbon fiber main blades, 3xDS610 servos, 1xDS650 tail servo, flybarless head and the Align 3G flybarless system. Both kits include both an aluminum tail boom and a carbon fiber tail boom. There are reports of a new 3G package that includes a Castle Creations ICE 120 ESC as well as the new 700MX motor and CNC main gear. (more…)