I have just built up a trex 500 and while maidening I can not get the tail to stay set, it is moving up and down as well as around, as well at hover the throttle actually slows down when it should be speeding up while in normal. The computer radio is programmed as per instructions, the same radio also flys a trex 6oo with no problems at all. With Idle 1 the head speed is constant. The Gyro is programmed properly and is working in HH mode. It seems to be a faulty bec-esc unit, 2 other people say that as well. Any thoughts, has any one had a bad bec-esc? The Trex 600 is a joy to fly, a very good flyer, I like it much more than my nitro raptor. Thr Raptor has been parked at least for now.

Bobbling is low headspeed. Tail won't hold at low head speed as well. Can't get the tail to hold until you can work out the low head speed problem.

ESC? Solder joints? Throttle curve too low?

My 500 bobbed up and down once or twice due to low headspeed. I finally figured out that it was a bad cell in one of the packs that I had wired together. I was using two 3s 2170 packs until my dedicated 6s packs came in. I pull that bad pack out of my rotation and never had another problem.

Have you used a tach to measure your headspeed? You can't solely rely on your throttle curve to estimate headspeed.

Like HeliSmith stated- "Can't get the tail to hold until you can work out the low head speed problem." Get your headspeed up and see if that solves both of your problems.

I will try a higher head speed. Thanks

It took 95% power setting on Idle 2 to get the wagling stopped. I am surprised that it needed such a high head rpm to straighten things out. The 600 runs very well at 70%. The advice to increase head speed was spot on, thanks for the advice. I do not have a heli tach but the head speed has to be on the north side of 2600rpm. I guess I have a few more things to learn on the 500.

Increasing the head speed worked, I had to take Idle 2 up to 95% to get the needed speed but now the tail stays where it should, at that speed a 2500 Battery will not last long, i hope to get 6 minutes. Thanks for the advice.

I get about 5 minutes of agressive sport flying(loops, rolls, flips, ect) with my 6s Flight Power Evo25 2500 packs. I am running the 13T pinion and a 100,95,90,95,100 throttle curve. I don't know exactly what my headspeed is either but it flies great! After 5 minutes I put about 2000mah back into my packs. Flight times are not long but boy are they fun!

Boystoys, I am using the same battery so I will adjust my time down to 5 minutes and go from there. I hope the 500 flys as good as the 600, with the high winds here yesterday the shake down was done in a garage.

Glad to hear you got it working. Yeah be good to your lipos and you will get lots of cycles. Heat and overdischarge are the biggest killer.