disguy2k

Hi Guys,

After reading these forums for a few months, I finally decided to join. After having my TREX up and running for the past few days, there are still some things that aren't quite right about it. My setup is as follows;

JR X2610 Tx
JR 6 channel Rx (mounted at front in front of servo enclosure)
JR G490T Gyro (mounted above tail shaft entry)
JR 3 x 9g servos for cyclic/pitch
JR 6g servo for tail

ALIGN 25A ESC (mounted at front payload under servos)
ALIGN 400L Motor (with heatsink)
ALIGN Standard ABS blades

E-Tec 11.1 V LiPo (2400 mAh)

Now, the most annoying problem I'm having now is radio glitches. I have the Rx just above the ESC currently and have read that the BEC inside the ESC is a main cause of radio glitches/interference. Has anyone else been able to confirm this? The only crashes I've had so far were caused by the heli deciding to roll/twitch all of a sudden. Also, after about 10 minutes flight, (hover) the controls seem to be a tad more erratic. I really don't want to dive into any more advanced manuevers if I don't have full confidence in my setup.

Second question. Does anyone else have ESC overheat shutdown? Does side mounting eliminate this? Right now I get about 10 minutes into a hover and start to lose lift, even though I still have 15-20 minutes of battery left! I guess what I'm trying to do is find the offending component (motor, battery, ESC) as at this stage the battery is only warm, ESC is quite hot, the motor is VERY hot.

Third thing. What is the best way to 'dial in' the chopper? just trial and error with the control arms? Or is there a proven method out there? Currently, the best I've gotten is to match the control arms with a pair of calipers, but the heli still takes off to the left, and will never seem to settle into a non drifting hover. (trims on the Tx seem to miss by half a click either direction).

I've done enough crashing/repairing on my Esky FP, and don't want to repeat the exercise on the Trex. If I can keep the major crashes to a minimum, I'll be a happy chappy

Thanks again for reading this long-winded post, but might as well try to cover everything. BTW it was you guys in here that sold me on buying the Trex too!

luc-RCU

1) try the berg RX. A lot of people got these glitches disappearing with these great Rx (4, 5 or 5 ch).
2) To avoid esc overheat use at least a 35A esc
3) try and tset..and try...and test...

disguy2k

I re-routed all the electrics, and did a test run with a smaller battery (Align 11.1 1800 mAh) and it seemed to be alot more stable. I also got some wood dowel, and wrapped the antenna tight around that. It looks alot neater, and no radio glitches so far!

The only drawback is my weight balance is back to being tail heavy :| I think i'll have to re-engineer some kindof new battery mount, that still allows for better airflow.

tanasit

When wrapping the antenna, wrap it in one direction half way and tape that spot then wrap it in the opposite direction (not on top of the first part but keep on going lengthwise) . This is how the car guys have been doing and some TX set even came with a wrap plastic template that let you do just that.

clovus

where did you get your TREX from? I was thinking about upgrading soon from my mini dragonfly.

disguy2k

From www.wattsuprc.com.au Very fast and great service. They are the primary distributor for Australia. They're just starting to get the Carbon Fibre stuff in stock now too

Its a fairly costly exercise to set up completely tho. a decent setup will still set you back around the $1000 mark! But certainly well worth it. Especially when you go back to your dragonfly. Your fear of crashing it goes away and you can get it to do some pretty cool things :d

tony_kilwein

I have looked at this with a scope and meter, due to having problems also.
Have a showgun 400 heli having problems with.

Found the following

Different controllers will drop out any where from .5volts to 2.5+volts going to the receiver for very short times.
If the receiver has better decoupling caps inside it will ride thru, if not the rec freaks out!! (not enough power to REC)
I have looked at different brands and found different levels of voltage drop outs.
The response/capability (current wise) of the BEC part inside the controller is a big factor.


1 The BEC portion of the ESC must be capable of supplying enough current!!!!! (high speed demands), (Fast response)
2 The decoupling caps inside the ESC and BEC is lacking on some controllers, more or less however you want to look at it.
3 The EMI noise spikes coming from the speed controller and the routing of the motor wires.
4 shielding the receiver or placing further away from high current motor wires.
5 adding a inductor and caps inline as a power filter between the two parts, on the power lines going into the rec.
6 adding feritte bead on the servo/power lines from the SC to REC.

I have found the above will effect the problems and also extended the range check in my case. (doubled it!) 35ft to 80ft.
This was with 5 controllers and 4 receivers.

Tony

Ozydego

As far as trimming goes, change the length of the control arms the tiniest bit and then see if you can get the trim inside one of the clicks. The finest tuning you can do is on the heli itself, not the radio. The perfect heli would be one with all trims on a transmitter still at zero. hehe wouldn't that be a perfect world. As far as heat is concerned with esc's make sure the side of the esc that gets hottest, I think its the side w/o the label is facing out, so the blade wash can cool it, also, make sure the wash has a straight shot down to the motor as well if possible. Canopies can prevent the blade wash from reaching key components so make sure they are positioned strategically. Also, the main source of glitching that I have heard is the reciever being too close to the interference sources, ie: motor, ESC, and servos. The reciever and antenna should be as far away from these as practical. at least 7cm I do believe....

disguy2k

So the best way to trim the control arms would be to leave them on the heli, and twist the centre shaft a fraction till its right? I think I will wait till next week when I get my control arm upgrade kit. then re-trim it from scratch. After a good 20 or so hours, I think I'm nearly dialed in

dma777

if anyone knows how to fix this problem pleasehelp.My problem is with the T-REX HELI, the cyclic response is completly messed up and I have all the best equipment there is to get like berg rx,thunderpower11.1 lithium,justgofly outrunner brushless motor tremendus power,hs 55 servos,jr gyro,pheonix 35 speedcontrol,so my only problem left is when I turn the throttle up to full and the throttle stick is in the middle everything is good but when I give it up collective/throttle it goes haywire on,not so good and I could not try to fly with this problem,plus when I give it left or right aileron or elevator it mixes elevator and aileron together which in turn I still can't fly with this problem. thanksdma777

dma777

plus I have checked for the linkage being uneven and they all seem to be,I also made some travel adjustment on the pitch and that I may have had tooooooooooo muuuuuuuuuuch positive and negotive pitch.

disguy2k

Have you got the right swashplate type in your transmitter? The Trex isn't CCPM, so you need to only have channel 6 applying pitch. disconnect your motor from the ESC and bring up the throttle. none of the other servos should move when applying throttle only the pitch servo.

dma777

yes that is how I have it set up and I have just noticed when I have full collective pitch the tracking on the main blades are about 1 inch 1/4 off tracking, how do I fix this problem.THANKS FOR THE HELP DISGUY2K. 'PS' I think this is why I AM MAINLY HAVING THIS OUT OF CONTROL PROBLEM.

Ozydego

The control linkages that connect the blades pitch to the swash need to be lengthened or shortened. Place a small piece of colored tape ( trim tape) on one blade. Spool up the rotor, and find out which one is off. Both can be off, lengthen one, shorten the other until the blades are lined up. By the way, this can be used to change pitch as well if both linkages are changed the same distance.

disguy2k

The best way is to get a pitch gauge. Most of the places that sell the Trex also sell the pitch gauge. (It should be less than $10). Another way to do it is put a bit of coloured tape on the leading edge of one of the blades. Put on some safety glasses and look at the blades with the motor spinning nearly fast enough for takeoff. The blade that is tracking high will have too much pitch, (or the low one doesn't have enough pitch) To adjust the pitch, you need to extend the control arm on the high blade to decrease the pitch. The control arms on the main blade are for making large changes, and the longer control arms which attach to the washout assembly (I think, I'm at work so dont have a heli to look at) are for making finer adjustments. Either way it shouldn't be much to get them back in line.

Normal pitch should be

0 throutle = 0 degrees pitch
50% throttle = 7 degrees pitch
100% throttle = 11 degrees pitch.

The pitch gauge is cheap and will save you lots of time in setting the blades up!

fredycompean

I want to keep this topic on......

Thanks for your help.