View Full Version : RH Tail Authority Intermittent in Flight
Nose left was fine every time, Nose Right, (against torque) was fine in hover but in flight would not turn, then would release all of a sudden & swing over. I replaced the notched thrust bearing races & thought the problem fixed. Until the next flight & it was still there. The pitch linkages were so smooth you could almost blow on them & they would slide on the tail shaft. The only thing left for me to check was the hub. I put it on the lathe this morning & found it was out of round by .025" WOW! Tell me I've found my problem someone... PLEASE!!
vitek
12-03-2006, 05:42 PM
Make absolutely sure that the TT is not slipping. A left rudder input would seem fine because a clockwise rotation heli will naturally nose left on its own. A right rudder input might seem slow or just a little weird.
You also might want to make sure that the pitch slider is near center and you're getting full travel in both directions.
rkeith2
12-03-2006, 06:29 PM
Make sure the arrow drive shaft is NOT slipping from the dogbone through to the tail gearbox.
I've slotted the drive shaft at the point of set screw contact, I doubt it slips at all. Pitch slider is in the center. The input I give during flight seems not to apply then it connects & over travels a bit. I think it has to do with the bent T/R hub. the next flight will tell & I'll post the results. But it's snowing up here now, maybe next weekend.
Well I test flew the Intrepid & the flight snag is still present! :arggg: I have large tail blades on this machine could that be it??? Seems unlikely to me but I'm thinking of putting the stock blades on just to bring it all back to factory spec. The linkage is so smooth you can almost blow on it to change pitch (with the servo disconnected) Any ideas would be welcome.
Gyan, maybe a glitch, interference from the ignition (I believe you have a gasser). I'm thinking along those lines. I hate these problems. You'll get it figured out. By what you are saying, the linkage is taken care of.
dc :
It can't be a glitch it's repeatable at the same flight parameter, besides I'm running PCM.
FOUND IT!!!
It seems that the FUTABA 9254 servo with 47 oz. on the Intrepid cannot handle a tail blade that is 105mm long with a chord of 31.5mm. I swapped out these tail blades with the stock plastic ones & problem solved. Who would have guessed?? :arggg:
lperagallo
12-10-2006, 05:12 PM
Gyan, I am surprised that the 9254 can't do the job. I am running 110mm Vblades on my Intrepid EB with no problems with a 401/9254 combination. I would be concerned that maybe the servo is damaged or about to quit. There have been plenty of write ups about that servo going bad. While I haven't experienced any issues with the servo and I'm pretty tough on them with the number of crashes I've had on both the gasser and my Raptor, I have read about many people having the servos fail. They do work very hard in HH mode.