jhomman27

I just got a trex 450s. I am having 2 problems with it.

1.) I can not get the blades to track at all...if i bring the high blade down, it now becomes the low blade....any ideas,

2.) is it normal when the battery is fully charged and it put it in a hover i have to trim out a counter clock wise spin and as the battery goes down i have to trim out a clock wise spin...any ideas?


Thanks for any help

john_doe

regarding the blade tracking... are you using the stock 'fiber' blades? if that is the case, throw them away 'cause they are useless. i have 3 sets of these 'fiber' blades that came with the xl/s kits, and they are all 'bent'.

juneebear

jhomman27,

Here's a link for some videos regarding your questions : http://www.helifreak.com/showthread.php?t=41692
I hope this helps.

juneebear

windbender

for the tracking:
I had this with 325 pro woodies and the problem was faulty dampers and bent flybar rod. it was a cheap fix.

trimming:
sounds like a headspeed thing, since as the HS can change as the battery gets weaker, the torque to the tail would change. Or perhaps you are flying in rate mode, then it becomes a gyro thing. this assumes no slop on you head links from swash to flybar.
Wb

Georges Payne

Regarding the tail drifting as the battery goes down, I had this with my Blade CP PRo with a G90 gyro. That gyro is not very sophisticated and it does that ; this is well documented in the forums. With a higher end gyro like the GY401, the tail is rock solid from the beginning to the end.

In the case of the G90 gyro, (and a couple others that are labeled differently but are in fact the exact same gyro) the voltage of the battery serves as the reference point for its operation. As the voltage of the battery decreases, the gyro will think that the orientation of its original point of reference has changed when in fact it has not.

Maybe that's your case?

Georges

alienteabagger

hmmmmm... I wonder if running the G90 off a separate battery (like a 9v) would help.

VinceHerman

9v would let the smoke out.
Better would be the dimension engineering regulated Park BEC.
[link=http://www.dimensionengineering.com]www.dimensionengineering.com[/link]

Georges Payne

Yeah maybe, but don't forget that the gyro drives the tail rotor servo, and that servo is working pretty hard. So I guess it would have to be a rechargeable battery pack that has enough juice so that it doesn't drop in voltage as the flight progresses. Also, I think the ground wires of both packs would have to be tied together to prevent voltages from floating. I think it would be a significant increase in weight.

Or did you mean drive the tail rotor servo from the main pack, and the gyro on a secondary pack? Not sure if that could work or not.

As a fun project, I think it would be worth a look to try a voltage regulator somewhere on the line to make sure that the gyro gets a precise voltage all the time.

Do separate BECs have a voltage regulator?

Why isn't the voltage regulator in the stock ESC correcting for that?

Not sure though, just speculating.

VinceHerman

The Park BEC uses any voltage input, even the flight battery, and use an efficient switching design to accurately regulate the voltage.

I have to admit that I am not familiar with the voltage induced drift on the g90 gyro, but I do know that the Park BEC is nice to use, and would be better than a 9v battery.

jhomman27

i did go buy some new blades...this is not the first time that i was told that the 325 fibers sucked....i will let all know how that works out.....

alienteabagger

Yup.... As the battery wears down the tail will begin to drift and you need to use rudder trim to get it back in line. My G90 is set-up rock solid, no creeping, no wagging. Holds great on a fresh battery. But once the voltage gets low it starts to slow drift if left un corrected. Im so used to it that I do it all automatically.

That's how I came to wonder if it's possible to power the gyro & tail servo off a separate battery.

jhomman27

just to let all now i switched to the 325 pro blades(wooden) and the heli tracked perfectly....then on the second flight with the rudder gear broke...just not my luck.....but thank god no damage but the gear

stevennh

Silly Question, did you try to trim the blades using the upper or lower linkages? One turn on the upper linkage = two turns on the lower one. I rough in tracking with the upper linkage and tweak with the lower one. I don't know about you guys, but sometimes I still end up with a very small tracking error (less than a blade thickness off). Small errors don't seem to introduce much of a problem.

Steve

jhomman27

Hey steve sorry it took so long to reply, but as soon as i put the wooden blades it was tracked.

I track the same way that you do...top to get it close bottom to tweak and fine turn.