T-Rex 450X Build Progress & Photos

[rob_jones]

Well, I must really enjoy punishment! I have taken the Zoom 400 as far as I care to. I've decided it's time to try something new. So about two weeks ago I pre-ordered a T-Rex 450X from Flying Hobby. The 450X is an improved version of the T-Rex 450 that addressed many of the issues people discovered with the original. Think of it as a "V2" T-Rex. It impressed me how quickly Align (the manufacturer in Taiwan) updated the kit and seems to really stand behind its products.

I had high hopes for the Zoom and it's a decent copter. But it's far from perfect and required many modifications to make it fly reliably. My goal with the T-Rex is to build and fly it straight out of the box. If it ends up needing any mods, it'll be on eBay! :wink:

http://home.alltel.net/jshell01/t-rex/trex_1.jpg
I got a notice yesterday in my PO Box that I had a parcel (Yay!) and rushed home after work to check out my new toy!

Since nobody ever offered a convincing arguement about the best motor, I decided to try the brushless motor offered by Align. Flying Hobby offers it in a bundle with the helicopter for $199. Not bad considering I paid $240 for the Zoom with a brushed motor.


http://home.alltel.net/jshell01/t-rex/trex_2.jpg
One thing I like right away is that when I opened the box, it was obvious that something was in it. I built a Hornet some time ago and remember opening the box and saying out loud "Where the hell is it?". The kit looks like a lot of parts, but as I'll point out later, it builds quickly.


http://home.alltel.net/jshell01/t-rex/trex_3.jpg
I don't know if I should thank Align or Flying Hobby, but the kit includes 3 sets of main rotor blades. Two sets of woodies and one set of what appear to be ABS plastic. I'm also eager to try the MAH Carbons that worked so well on the Zoom.


http://home.alltel.net/jshell01/t-rex/trex_4.jpg
Another nice touch: The kit includes two plastic parts boxes, a foam blade holder, two different sized minature screw drivers, two allen wrenches, and a bottle of green locktite. There's a lot of stuff in that tiny box!


http://home.alltel.net/jshell01/t-rex/trex_5.jpg
Completed rotor head, washout and swashplate.


http://home.alltel.net/jshell01/t-rex/trex_6.jpg
Completed main frames. I didn't get a shot if it, but the main gear is unique. It uses a split gear configuration like a Sceadu or Freya to provide a constant drive for the tail rotor and incorporates a cooling fan for the motor.


http://home.alltel.net/jshell01/t-rex/trex_7.jpg
The swashplate and washout. More nice touches here. Metal ball links and adjustable pushrods! All pivot points have a ball bearing also!
:cool: One constant annoyance with the Zoom was that it was just about impossible to get the blades to track because there was only one adjustment point and it made changes that were too coarse. The T-Rex has two points and one makes fine adjustments, the other normal ones. The ball links can only be snapped on in one orientation, but with fine and coarse adjustments possible, tracking the blades ought to be very precise.

All the head and washout links are very smooth and there is no binding. I did have to remove some mold flashing here and there, but it didn't slow me down too much.

To get the T-Rex to the point shown above took me less than 2 hours. It goes very quickly, even though it looks like a lot of parts. The instructions are passable, but the engrish translation leaves room for improvment. Thankfully, the drawings are very large and clear and it could easily be assembled by using them alone.

I've read lots of speculation that the T-Rex is simply a scaled down Raptor. That's not really the case. It's more like a Raptor/Sceadu love child; it has features of both. The tail drive system is straight off a Sceadu, while the control system is similar to a Raptor. The head is different from both, but mostly resembles the Hirobo. Overall, with the exception of the collective pitch mechanism and aileron servo arrangement, it doesn't share much with a Raptor.

I'll probably finish the build tonight and have more pictures loaded tomorrow.

[jhodges]

Hey Rob .... make sure you bring it to Mac's this weekend !!! I'd like to see that little sucker !

[rob_jones]

.... make sure you bring it to Mac's this weekend !!!

That's the plan! :mrgreen:

[WillJames]

Sweet Mini-Review Rob. Keep it coming please!!!

Now that is what I'm talking about!!

Can't wait to see it at Mac's!!

[SteveK]

Wondered how much the shipping was from Flying Hobby, if you would not mind telling. Tried emailing them several times but never could get a reply.

[rob_jones]

Wondered how much the shipping was from Flying Hobby, if you would not mind telling. Tried emailing them several times but never could get a reply.

Sorry, I meant to mention that! A friend and I ordered together and paid $22 each for shipping ($44 total). I was quoted $26 for a single kit. That's kind of a lot, but it only took 3 days to arrive from Hong Kong. I expect that some US distributers will start carrying these and when they do, shipping will obviously be much cheaper.

[rob_jones]

After about another hour and a half, the T-Rex mechanics are complete. All that's left is to install the electronics and set it up. Despite what seemed like a lot of parts, the construction is actually fairly simple. The overall size is a little bigger than the Zoom/Shogun and it's heavier. But the weight is put to good use with things like ball bearings, ball link connectors, and reinforced parts. Also, the blades are about 10mm longer than Zoom blades, so that ought to offset some of the extra bulk.

http://home.alltel.net/jshell01/t-rex/trex_8.jpg
http://home.alltel.net/jshell01/t-rex/trex_9.jpg
Completed tail rotor assembly. Again, very similar to a Raptor and Sceadu. The pitch lever pivots on a bushing and the idler pulley has a ball bearing in the center. The instructions don't point this out and it took me a little while to figure out how it went together.

The pitch mechanism is very smooth and has very little friction.


http://home.alltel.net/jshell01/t-rex/trex_10.jpg
The split gear drive system. The lower gear powers the tail rotor and you can see the short shaft that goes to the tail drive pulley. It's a constant drive system which means the tail rotor is always turning with the main shaft. The upper gear contains the one-way autorotation bearing and the lower gear bolts directly to the main shaft.


http://home.alltel.net/jshell01/t-rex/trex_16.jpg
Integrated cooling fan. Pretty slick. I'm hoping that I can position the battery beneath this gear to help keep it cool.


http://home.alltel.net/jshell01/t-rex/trex_11.jpg
Completed mechanics. I don't have a gram scale to weigh it, but I think I saw some at Wal-Mart for $30. If I can find one, I'll get it. I'm curious to know what it actually weighs.

The skids don't have set screws where they go through the plastic struts. They have to be glued. There are "flats" in the struts and if the glue doesn't hold, I may drill them out and put some screws in. The tail boom struts and tail rotor pushrod are carbon fiber and pre-built.


http://home.alltel.net/jshell01/t-rex/trex_12.jpg
Anodized tail boom and tail boom mounted servo. No chance of it rubbing on the main gear! :D


http://home.alltel.net/jshell01/t-rex/trex_13.jpg
The kit includes 4 pinion gears. They use a set screw instead of being pounded into the motor shaft.


http://home.alltel.net/jshell01/t-rex/trex_14.jpg
Extra parts are also included. A very thoughtful touch.


http://home.alltel.net/jshell01/t-rex/trex_15.jpg
Align brushless motor installed. No cutting of the frames was needed and it includes the proper size mounting bolts. The motor is an interesting design. It's an outrunner (think Axi), but the rotating can is housed inside an outer casing. So the outer "can" does not rotate, but you can look inside and see the outrunner.


Overall, the T-Rex looks like a good value. Of course, none of that matters if it doesn't fly worth a damn. I should have the radio gear installed tonight and will attempt a test flight under the lights at a nearby school yard.

[Hotshot Charlie]

Hey Rob,

Keep us informed on the first flying experiences. Thanks for all the pics and info, it looks very promising !!!

[bighands3d]

Can't wait to fly it at mac's get it done. looks Awsome.

Ol' century will have to step it up a bit. But there's is close to being finished saw some pics of it today. But I like the T-REx looks like a contender.. in the submicro class..

[rob_jones]

Well, I didn't get a whole lot done last night. I installed the servos and started working on the setup. But I'm having a hard time figuring out where to put the RX, gyro, and ESC. I wanted to have the battery under the fan in the main gear and it fits perfectly in that spot. But it makes the copter way too tail heavy, so it will have to go up front.

I ended up putting the gyro in the very rear of the frames directly above the rear landing gear strut. I think the RX will be on the underside of the frames and the ESC will go beneath the fan. Using this arrangement gets the CG close to where it needs to be and all the servo leads reach without having to use extensions.

I'll get some shots of the layout once I know for sure where everything is going.

[rob_jones]

Except for some final setup, the T-Rex is ready to go! Installing and setting up the radio gear took longer than the assembly of the kit. I still need a few more zip ties here and there, but it's close enough for a test flight...maybe tonight.

http://home.alltel.net/jshell01/t-rex/trex_17.jpg
T-Rex 450X assembled and ready to go!


http://home.alltel.net/jshell01/t-rex/trex_18.jpg
JR 9303 transmitter for a little size perspective. Overall, it's a little bigger than the Zoom/Shogun, but smaller than the Kysoho EP Concept. So I wouldn't really call it a "micro". "Sub-micro" maybe?


http://home.alltel.net/jshell01/t-rex/trex_19.jpg
Castle Creation Phoenix 25 ESC strapped to the side, under the cooling fan. You can also see the JR R700 receiver under the frames.


http://home.alltel.net/jshell01/t-rex/trex_20.jpg
The receiver. Looks like I need some zip ties!


http://home.alltel.net/jshell01/t-rex/trex_21.jpg
Aileron and Elevator servos. The Blue Bird BMS-371 servos have 1.5kg torque and .12 second transit time. Not bad for $13.95. They are a tight fit and the openings needed to be filed a bit. Especially for the Aileron servo. I'm not crazy about the Z-bends, but maybe on a copter this small they'll be okay.


http://home.alltel.net/jshell01/t-rex/trex_22.jpg
The Collective servo. It was easy to set the arm at 90 degrees for the 0 pitch setting. I never could get the Zoom exactly right. This one was as easy as a Raptor. Total ptich range should be 21 degrees. I don't have a micro pitch guage, so I'm going to have to eyeball the pitch setup. You can see the velcro on the lower tray for the battery.


http://home.alltel.net/jshell01/t-rex/trex_23.jpg
Gyro location. The MS-44 is a pretty good and lightweight heading hold piezo gyro. Setup is similar to a GY401, except it lacks a "super servo" mode. I used another Blue Bird servo on the tail. This one is smaller than the BMS-371 (I forgot the model number), but still has 1.2kg torque and .11 second transit. It might be a little slow, but I'm going to try it anyway. If it doesn't work out, I'll go to a HS-50 instead.


I really hope this thing flies well. I like it so far and will really disappointed if it's a dog in the air. I'm trying to keep my expectations realistic though. The only suitable battery I have right now is a Thunder Power 1320 3-cell (first generation). If the copter shows promise, I'll probably spring for a 1900 2nd generation pack.

[Hotshot Charlie]

Awright !!!!! First class job. I'm not familar with the gyro you are using. What is it and who makes it?

Thanks for all the details !!!

[rob_jones]

Thanks!

The gyro is made by MS Composites (they make the Hornet). I got that one from DeeTee Enterprises. But just about anybody that carries MS stuff should have them.

[pilotError]

Cool,

I'm waiting on ordering the motor until I see how you make out. Modefo is selling the T-Rex now for $169.

http://www.modefosheli.com/specials

This motor is dirt cheap, and they have a 25 amp esc that is also cheap. They have the info up on helihobby. I have a pico pro, and have been holding off on a zoom. Since winter is coming fast, I wanted something I could take to a local park and fly.

Mike...

[rob_jones]

T-Rex Flies! (Sort of)

I had a chance to try out the T-Rex at Mac's fun fly this weekend. I was only able to hover and do some slow circuits (more on that in a minute), but I'm very pleased. It is very smooth and feels responsive - as a habit, I start out with 20% expo on every model and then adjust from there. The blades tracked perfectly (Woo-Hoo!) with no adjustments. It seemed like the head speed was a little low, but I didn't have time to make any adjustments. And since I don't have a micro pitch guage, I had to eyeball the pitch setup - so it might have too much pitch. But the short flight was very promising and I think I'm going to like it!

The reason the flight was so short is because my 1st gen Thunder Power 1320 LiPoly is not up the task of flying this chopper. It needs more juice. After only about 2 minutes of hovering, it settled to the ground with a fully charged pack - I later used the same battery in my foamie for 10 minutes and it felt strong as ever. I borrowed a 2nd gen TP 1320 and it was better, giving about 4 minutes of flight with some light figure 8's thrown it. But it's clear that a 1320 LiPoly is not enough battery for the T-Rex. I'm going to have to cough up $80 for a 2100 (although I was kind of expecting this to happen). The TP 2100 is the same width as the 1320, so it will perfectly fit the battery tray and since it's longer, ought to fix the slightly tail-heavy problem. TP also has a 1900 pack for $75, but it's much wider and shorter than the 2100 and probably won't fit as easily. Besides, the 2100 is only $5 more with close to twice the capacity of my 1320.

As soon as I can get my hands on one, I'll post how it really flies...

[big-al]

sorry i missed getting a look at this one. I also could have loaned you a bigger pack to use.

FYI, I was troubleshooting the zoom down on the north end. sounds like you're pulling more out of the pack than it will allow amp wise. i'm using the himax 2025-4200 and it pulls around 15-16 amps itself. i was getting around 10 min on a 1660 mah pack and an 1800 mah pack, both rated for 10c.

[rob_jones]

Yeah, I had been using the same battery in a Zoom with a 2025-4200 and it worked fine. I don't have any data on the Align motor, but it obviously pulls more current than the TP1320 can deliver.

I really think the 2100 10C pack will do the trick. The 1900 probably would, too. But the 2100 will fit the battery tray better!

I didn't see you working on the Zoom. But if my experience was anything like yours, you probably spent way more time working on it than flying it! :arggg:

[big-al]

well i was messing with some previous issues as well as getting it back together after a stupid on my part while initially setting it up (ie- do unplug your motor when working on the throws/trims etc.). so far I'm pretty satisfied with it. I put some really light century hummingbird paddles on it to speed up the cyclics, a 240 on the tail, and so far the only flying quality left to tackle is to tune the head speed up a bit more. it does fine while rolling it, but when I flipped it end over end, the tail blew out when inverted as well as when doing a tail first descent. It also doesn't like winds more than 10-15 mph. I eneded up having a fin strike and she went in. damage so far is one horizontal fin pulled loose and a pretty good nick in one blade. I wish my other crashed would be so lucky!

[rob_jones]

T-Rex Flies!

My Thunder Power 2100 11.1V battery came Thursday and I finally got a chance to really fly it today. By the way, the all up weight (with TP 2100) is 637 grams.

The new battery made all the difference in the world. I quit flying after 10 minutes because my hands were getting very cold! It feels like it has roughly the same power to weight as a 30 size glow copter and is very responsive. I only had time for one flight and I was mostly interested in duration, so I didn't get too crazy with it. I'm also working on the pitch curves, so it didn't go inverted yet.

There was about a 10 MPH breeze at the time and it handled the wind fine. 3D Lee and I took turns at the sticks and we both came away impressed. I think the T-Rex is a keeper, finally!

I've gone through a lot of helicopters trying to find a good and reliable electric (Kalt Whisper, Kyosho EP Concept, Century Hummingbird, Zoom 400, etc). I might have finally found it!

I'll get the pitch curves set this week and next weekend we'll find out how it handles 3D. :glasses:

[Laddy]

I am putting my T-Rex together now and have a few questions for you. Are you using the Align ESC with the Align motor? If not which one are you using?
Also what gear did you use?
Last one, I was told to use a Berg RX but had an Electron 6 for it. What do you use?
Sorry for all the questions but I really only want to buy the stuff once. I had an Eolo and it was a money pit!
Thanks
Laddy

[Hotshot Charlie]

Hey Rob, first class.... I am glad this one seems to be the ticket. I am going to wait until Century's little beast comes out, then check it out after that, I will make up my mind between the T-Rex and the Century.

Please keep us informend on the T-Rex !!!! Yes, the Shogun was a time and financial money pit.... more time and frustration than money..... but...... anyway, glad to see a good small electric heli !

[rob_jones]

I had an Eolo and it was a money pit!

I haven't had an electric that wasn't! I'm hoping the T-Rex will reverse the trend!

I'm using the Align motor with a Castle Creations Phoenix 25. I'm using that ESC because I already had it and I like the flexibility of the CC controlers. If I didn't have it, I would've probably tried the Align controller.

I used the 13T pinion for now. But I will probably also try the 11T.

I'm using a JR R700 receiver, but the Electron 6 ought to be fine. I would put a choke on the lead from the ESC to the RX, though. I've seen them advertised online (RC Groups) and they're cheap insurance. I had real bad glitching on mine until I installed a choke.

[rob_jones]

Rob,

I debating waiting for the new Hummingbird, too. In fact, I have one pre-ordered. But I believe that past performance is a good indicator of future events. And so far none of the Hummingbirds have been worth the wait. The pictures of the new one look great and I do hope it's a winner.

[Big Zoom]

I have seen guys try to run the 1320 on such a big micro heli, and I just want to say more power to them. I run the gen 2 1320 on my hummer, and the gen 1 barely handles 10.5amps cont. without heating up. I'm suprised your gen 1 did not swell up.

I'm curious to know exactly how many amps you are pulling with that align motor which is supposedly almost a 300 watter.

What are your temps on the pack at the very end of a run?

[rob_jones]

I'm also surprised that the 1320 didn't swell up. I've had it for a while and it's getting pretty tired, so I figured it was worth the risk.

I agree with you that the 1320 just isn't enough juice for a copter this size. It got very hot in the Zoom with a Himax 2025-4200. Maybe when a 20C version comes out...

I'm curious to know exactly how many amps you are pulling with that align motor which is supposedly almost a 300 watter.

Me too! But I don't have a way to measure it. I don't deal with electrics enough to invest in the test equipment.

So far, I've only flown the T-Rex once with the 2100 gen2 (the weather has not been cooperating). But at the end of the 10 minute flight, the pack was a little warm. It hadn't started to lose power yet, but it was getting dark and cold. More testing will hopefully happen this weekend.