Align T Rex 450X - RCCanada - Canada Radio Controlled Hobby Forum
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Old 12-22-2004, 12:07 AM   #1
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Align T Rex 450X

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First impressions...

I had allready built one with no electronics and bought another complete kit (well almost complete I found when I picked it up). I decided to set aside the new kit as I am going to give it a serious dremmel diet to reduce the weight a bit.

The T Rex is a 400 sized motor in the same class as the Zoom/Shogun/Dolphin/Zap. I had a Dolphin which I just sold to fund this project so I had a comparison. I will say that I had the Dolphin up and flying with the stock brushed motor right away and it flew great. I just really hated the wimpy tail gear setup. Mine allready showed signs of needing replacement after only about 10 flights. I am one of these people that hate having to upgrade something right out of the box to make it useable and the tail gears were a definate problem.

I got the Align 400L (long) 2500 kv motor, 25 amp controller and 1900 mah lithium ion battery. the gyro was a Zoom (actually a Telebee renamed) heading hold gyro and I went with 4 Futaba 3107 micro servos (I like futaba servos, what can I say).

Well after going through many forums and deciding what pinion etc to use, I had all the info needed, or I thought so anyway. I had my radio settings done, modified my pitch guage to work on the micro blades, had +-9 degrees of pitch (some wonder how I got that without modifying the heli itself, but it just takes time adjusting linkages, a whole day of tinkering to get the sero arms perfect and all the blaa links, I am very meticulous in my setups).

Outside we go. I spool up on the driveway. after a few too many torque spins I decided I better start on grass, something the dolphin was very afraid of or it would shred a tail gear hitting a blade of grass. gyro was reversed. ok so I missed something. also reworked the tail linkage to clean that up a little better. 15 tooth pinion, throttle curve 0%, 75% and 100% (low mid and high) with mode 1 pitch setting -4, +4, +9.

I spool up, blades seem to be tracking pretty close. Half throttle not even close to taking off. full throttle the motor bogs down and it just sits there. huh? after all the setup time, I decide to top the battery up and try again. gives me time to tweak things. I take the motor out and check things over. yup everthing is free and smooth. belts not too tight to tail. I should mention I tried oth mid and high timing in speed controler setup, plus I tried setting throttle curve right up to 100% at mid stick up and even reducing the top pitch. okay so let's try the 13 tooth pinion and the slightly shorter blades...

well back outside. no bogging at any pitch with 100 % throttle but still no lift. back to the 15 tooth and back to bogging. okay I am startng to go bald now. tried everything. I write to buddies with t rex, I post on forums. I get suggestions to try all I have tried.....

off to align's website to chek the battery specs..... they have a discharge rating of 6C.... 6C? wtf is that? my 1320 mah thunder power batteries in my zoom had 10-12C average with a lighter heli and most use tp 2100's in a t rex. so 2 days of work gets me a cool cooling fan that looks like a heli....

Now I need some batteries. I will just use this pack as a radio pack as my heli radio needed new batteries. I have not talked to the lhs about these batteries yet but I need to tell him to stop selling them as a package as they just won't work with this motor and heli combo. not possible. tough choice now is go with a 3 cel 2100 (which generates heat) or go with a 4 cel higher voltage and drop the pinion. I think I will bite the bullet and go 4 cel now. I was considering buying the stretch kit for the second T rex and will need more poop. I will do a full pic spread of the dremmel diet version.
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Old 12-22-2004, 09:22 AM   #2
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let see her.......
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Old 03-18-2005, 11:53 PM   #3
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Well here is the newest bird in the nest pretty much finished. Thanks to Seb for painting the canopy up, I think it looks pretty hot. It was backwards from the way he normally paints so it was a challenge I am sure. Dude I love it!!!

I dyed everything black and added the eccpm conversion (which is painted black to match the rest. Being my second conversion, I was able to improve on the design a bit and will do the same changes to my other heli next..... here we go with pics

I got a bum motor and first flight lasted less than 3 minutes and the magnet shattered. It was so stable.... using my jr rx and wrapped the antenna around a piece of straw to make it small.

I mounted the servos from inside this time and wicked ca over the threads to keep them secure. this allowed the swash arms to come up way more level. I also added a small piece of balsa behind the front servo and shoe good it in. an aluminum brace goes across the frame above the left servo and below the right servo. this holds the servos tighter and keeps the frame from twisting under extreme pressure (this will be my 3d heli. I again went with all futaba 3107's and a zoom gyro. This heli has the castle creations 25 amp controller. I went through the standard setup, though I do have the phx link to hook it up to my computer through usb. I really like the soft start, it is so smooth. I had it on normal pitch and throttle curves (no governor mode) so I can't explain why 75% throttle would kill the engine, I had it undergeared if anything but most use the same pinion I was using with a thunder power generation 2 2100 mah lipo.
gyro is mounted diurectly under the main shaft so is most sensitive there needing less gain and more precision. The carbon tailboom is a nice fit.
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Old 03-18-2005, 11:54 PM   #4
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Tailboom mounted servo is standard, so are the carbon boom supports.
MMMM Carbon... I love these blades. cheap too. align is the mfg and they keep coming out with super affordable hop ups.... and here's the paintjob... pics worth a thousand...

there's actually a little more yellow in the horizontal fin but the light washed it out a bit, it's a fade like the vertical fin but white out to red. I had to put something on the fins to look better than plain white with such a smashing looking shell

I just got a motor lined up now and it's being driven over as I type this out. woohoo flying tomorrow.
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