Tail problems help meeeeeee!!!

[steve3065]

Hi all

Had my 600n a few weeks now, started it 1st time today all good except the tails wagging a little, iv tried changing the gain both ways to no effect

Everything brand new and working really well, im using a gy401 with digi servo
Cant help thinking im missing something small any one got a suggestion before the goodish weather goes away again

Thanks everyone

[garydraf]

Hi steve
I'm not sure how much experience you have on heli's so i'll appologise now if what follows is teaching you to suck eggs... I'm not overly familliar with the 401 gyro, however i'll assume your adjusting yor gain with the transmitter on channel 5 or something similar. I've seen this before on a similar gyro called a colco gy400 and it turned out to be a fault on the remote gain control. The problem your having could be one of many, firstly i'd suggest disconnecting the remote gain channel from your receiver and try to adjust the gain using the pot on the 401, this will only be tempory so as to prove that the gyro does infact function correctly and you have no mechanical problems on the heli itself. Swing the tail left and right and make sure the gyro works in the correct sense before running the engine or it'll add to the yaw axis error instead of suppressing it and piroute uncontrollably on take off. Assuming the wagging has stopped i' reconnect the remote gain and check your programing etc. How do you control your ATV or EPA? is it on the rudder channel 4? I'd suggest checking the amount of travel on you tail blades also.

Let me know how you get on.

Gaz

[steve3065]

Thanks gaz for replying

I would not be able to disconnect the remote lead ( ch 5) as the only way to adjust gain on the gy401 is through the radio.
My endpoints are set at 100% both ways on rudder (ch 4), its all connected up correctly and in the right channels, the gain at the moment is set at 30%.

The wagging is quite small but it is enough to prevent me from flying.

Thanks again

Steve

[garydraf]

where abouts do you have your gyro monted?

[steve3065]

just behind the main shaft, directly between the canopy mounts

[Philimon]

Perhaps this is more of teaching-one-to-suck eggs, but it does seem that its worthwhile checking that the gain channel is working. I'd suggest plugging a servo into the gain channel and checking that it moves as you set the gain. A y-lead would be useful, but not necessary. It could be the channel isn't functioning, or the gain is plugged into the wrong channel. I know I've made similar mistakes in the past.

[steve3065]

Thanks phil

just tried servo in gain channel working fine, and yeah everything is in the right channel

[Philimon]

hmmm.... Sounds like its the old trial-and-error time. Try using a different gyro? I know thats easier said than done, what with the GY401 costing £99 and all. Perhaps your local friendly heli flying may be willing to help? Maybe for Local Hobby Store?

Sorry I haven't got an easy fix for you.

[steve3065]

no prob thanks very much for helping ill ask at local model shop

[jamiesawyer28041978]

Hi there steve i got my self a 401 giro aswell the other week and going to get the proper servo (9254) for it , if your using this servo you might need the gain right down at 0 % , faster the servo the less delay you need. 9254 works at 0.06 s which is lightening fast . The servo on my tail is much slower 0.26 and ive got my gain at 100% and it may be the wrong way to do it (risk of getting my hands slaped here by the guys) but ive added 20% exp on the tail to dampen the tail down and its eliminated the wag till the proper servo comes in the post. Dont know if this helps but good luck (hait the tail )

[garydraf]

Hi Steve

I had a read at the GY401 manual on the Futaba wb site. There was a very valid point made above that the delay should be set to zero when using digital servo's, anyother value would continue to produce yaw error correction signals whilst the servo is driven, awkward to explain but it would cause the tail to overshoot and begin hunting! As for your travel... don't use the end point adjustment on channel 4 (rudder channel) instead use the limit pot on the gyro to adjust the travel on your tail rotor. You said your gain was set to 30%, did you have your gain channel set to switch between a low and a high value e.g 30% and 70% this allows you to switch between heading hold 70% and normal mode 30%. Personally i always leave mine set to heading hold and just stear the tail my self.

On channel 5 (your gain channel) you actually set gain by adjusting the end point or ATV (depending on manufacture of you radio) although you may have a value of 30% set on your screen perhaps it needs to be set to -30% depending on your radio. Maybe you've already tried this, but hopefully it'll help you get that gyro playing ball and get the t-rex in the air.

Gaz

[garydraf]

Hi Steve

Any joy getting your gyro set up?

[helihead]

have you got the gyro mounted on the correct pad ????

[trvo]

One other thing you should try, if using the thrust raced tail take it apart and on the outermost race of the thrust bearing take about 1mm off of the outer diameter with a dremel. That'll give it enough room in flight to not jam up...make sure you clean any burring off of the thrust after you've shaved it down and don't go into the 'race' part where the balls run. I've seen and experienced first hand this problem quite a few times and 99% of the time this mod solves it...

Trev

[jamiesawyer28041978]

Hi Steve

Any joy getting your gyro set up?

He has either got it going and flying his little heart out OR he is in the pub drowning his sorrows ,