T-Rex 250 Build Thread

[norstaroption]

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[Silverexpress01]

Removed - wrong place, sorry!

[kencol]

Do not tighten the main and tail rotor blade holders too much.[will create weird viberations]
The blades need to be fairly free to move in the holders.

Route the front servo wires through the right side of the frame or over the top of the frame.
As if you have a crash, the battery will crush the wires.

Do not over tighten the tail belt[difficult to gauge this one] better to be a bit on the loose side.

Do not make the pinion gear to main gear too tight.
You need to be able to feel a slight amount of 'backlash' between the gears.
[Hold the motor still, and move the main gear slightly back and forth with your thumb]
Its a bit hard to use the paper trick on this small model's gears.

Cheap Gyros will work OK once you are flying around, but will not hold perfect at the hover or full on 3D.
[MKS 291--292--293 etc] they have very fine Gain adjustment, only move it a very little at a time.

I had to re-program my ESC, as it was in aeroplane mode.[motor stopped with low battery]
You do not really want to be doing auto-practize with this seize Heli.[the blades have very little wt to arrest the sink rate when up collective is pulled near the ground]

You can just fit 1000mAh 3S batteries[get about 8-9mins flying], but you need to make two new canopy mount holes apx 10mm out from the origionals. As the canopy will not push right on.
You may need to trim away a little from the bottom sides of the canopy to allow it to fit snug across the front undercarrage legs all the way across.
[makes it a tad nose heavy, but will trim back easily]

[Rc_Collector]

Hello, guys sorry for the question but I'm newbie, I just oredered a T250 combo w/o gyro and tail servo, so my question is the 780 gyro will work with the t250 also with the t500 is there any difference between the 750gyro.and the 780.

thanks.

[halley]

Originally Posted by Rc_Collector

Hello, guys sorry for the question but I'm newbie, I just oredered a T250 combo w/o gyro and tail servo, so my question is the 780 gyro will work with the t250 also with the t500 is there any difference between the 750gyro.and the 780.

thanks.

Either gyro will work with either heli. Of course there's a difference, as they've changed the model number. However, both are excellent, and the differences are more about the way you set them up and not about the way they function.

[Rc_Collector]

Hi,,
what receiver fits into a T-250 compatible with spektrum DX6I
thanks.

[kencol]

The Spectrum AR6110e is good and small [also has good range for a small Heli]
Its very fiddley to wire up all the servos/gyro and receiver.
Take your time, you will probably have to rearrange things a few different ways to get it neat and stop the possibility of wires getting caught on something.

[Rc_Collector]

What you guys think about gp750 vs JR G270 gyro?

[halley]

Originally Posted by Rc_Collector

What you guys think about gp750 vs JR G270 gyro?

I used to love the GP750, but I've been having problems with it not initializing properly, only to spiral once I get ten feet off the ground.

[celm]

how many MM should it be between the bottom of teh swashplate to the top of the frame?

[Screamin' D]

Good advice here thanks all for posting. I'm looking into getting a 250 myself.





Dallas

[Steve Joblin]

Originally Posted by celm

how many MM should it be between the bottom of teh swashplate to the top of the frame?

The distance will change as you change the collective. As long as it doesn't bottom out at -11 deg pitch or have the washout arms jam against the head at +11 deg pitch, you should be fine.

[ValHeli]

Hi guys, I'm currently building my 250se and ordered a jr3500 for a tail servo as i've read in other threads that this gets rid of tail wag.

As i'm waiting for the jr servo, I noticed that the align servo fits just right on the servo mounts. The JR3500 being a bigger servo, what kind of servo mount do I use? Or do I just drill new holes on the stock mounts?

thanks for you help

[Jasmine2501]

Originally Posted by ValHeli

Hi guys, I'm currently building my 250se and ordered a jr3500 for a tail servo as i've read in other threads that this gets rid of tail wag.

As i'm waiting for the jr servo, I noticed that the align servo fits just right on the servo mounts. The JR3500 being a bigger servo, what kind of servo mount do I use? Or do I just drill new holes on the stock mounts?

thanks for you help

Do you also put salt on your food before tasting it?

You DON'T need a huge honking servo to work the 250. It works great with a DS290G or whatever they call it these days. Works ok with the stock servo too. To attach the 3500, you probably just use the top holes on the servo...

http://www.readyheli.com/JRPS3500G-D...o_p_34602.html (go look at the picture - it has two holes you can use)

Keep the 3500G to use on a 450-size heli.

[CHIEF-X]

wassup guys i just bought a used trex 250 and was wondering if its ok for the blades to spin freely in the drive direction without the tail rotor spinning and when you turn in in the reverse direction it dont move?? also when u twist the blade grips the swash turns about an eighth of an inch. is all this normal or is there some wear on the head and bearing.

also i need tx settings when useing a spektrum dx6i and a ar6100e really bad. i just wanna make sure all is well before i fly please help .

[Jasmine2501]

That all sounds mostly normal, but your description is somewhat vague. If you're not sure, probably won't want to be flying a 250 - they spin up pretty fast.

[CHIEF-X]

lol believe me i wanna fly it





nice video but ya need a better cameragirl lol tell her to lay off the zoom

can it really be that much faster than a 4g6??

Originally Posted by Jasmine2501

That all sounds mostly normal, but your description is somewhat vague. If you're not sure, probably won't want to be flying a 250 - they spin up pretty fast.

[Jasmine2501]

Originally Posted by chiefs_nut_58

nice video but ya need a better cameragirl lol tell her to lay off the zoom

can it really be that much faster than a 4g6??

Yeah we clocked the little sucker at 43mph with a radar gun one day, and that's not even as fast as it can go.

When you rotate the blades, in one direction it should be free, and in the other direction it should catch the gear, which should catch the tail and it should spin too.

[CHIEF-X]

dude heres what i got and i think its correct.

when i turn the main blades clockwise( direction of lift) they turn freely without the main gear.

when i turn the gear itself clockwise everything turns main and tail blades in lift direction

when i turn the gear counterclockwise just the tail turns

when i turn the blades counterclockwise (nonlift direction) they dont turn and neither does the main gear and i dont think i want to appy force.

i was wanting a good beginer throttle curve and pitch setup and also need some direction on dr& expo settings to help tone down center stick movement....but not to the point were im fighting myself.

i have a dx6i and a 6100e rx...... oh and a nother question is i have a ds410m on the cyclic along with 2 ds410's is this ok??

sorry i just got the little guy and am kinda new to the trex setup but i am pretty expirienced with walkera 4g6s's

[Varc]

I need to read through this thread as I'm just starting to build my 250. I'm at the stage where I'm threading in those pain in the ass ball linkages.
I'm sure as soon as I've accomplished them threads, the rest of the build should go quickly and smoothly. Well, maybe more smoothly then quickly as I want to do this thing right.
It's a pretty sweet little helicopter that already comes with all the aluminum upgrades we could want. Nice not have to purchase a bunch of cheap Microheli parts for shiny bling. LOL!
I can not wait to get this one flying. I love small helicopters and this one is going to be a beauty!