Hey guys I just finished building my third trex 450 se clone and took it outside to try it out. I'm gonna have to do a little blade tracking but all in all it way a good flight. The problem I'm having is while hovering the heli decided it wanted to jump about two extra feet in the air without any input from me. It also gave me a quick tail jerk to one side three or times also without any input from me. I fly just good enough to have kept it from crashing but I don't trust it the way it is. Any ideas on this will be greatly appreciated.
450 clone crazy and puzzled
- Thread starter hawk-i
- Start date
Derek
Well-Known Member
One thing that may have contributed to the sudden pitch jump would be the wind. The wind will push the helicopter upwards without warning. As me how I know that, lol. I was out hovering, in my early heli-days, and I didn't even realize that the wind had picked up and my helicopter jumped vertical 2-3 feet. It scared me so bad. I've learned to react to that sudden jump better since then.
The tail jerking....that could also be from the wind and/or your gyro settings. Without a bit more description or video, it's kinda hard to tell.
The tail jerking....that could also be from the wind and/or your gyro settings. Without a bit more description or video, it's kinda hard to tell.
murankar
Staff member
If the tail jerks while in a hover then I would check gyro gain on the tail. You would want to turn it down a couple of points at a time until the geek is gone.
If If it is happening sometimes then your issue could be binding somewhere. If you have a belt drive then one thing could be the belt jumping on the gears in the tail. If you have a tt then you could be missing teeth on the tail gears.
Recheck your gear mesh if you have a tt setup. Poor mesh could cause the gears to jump and strip.
Sudden head speed change could cause this also. One way to find out is to change your normal curve to 0, 40, 75, 75, 75. This will give you a good spool up and then give a constant head speed at about 60% throttle. I have set this way and I like it a lot better. Now it's about collective management so I don't bog the motor. My idle up 1 is 75% straight across and iu 2 is 85%.
Without more info that's all I have for you. With a good video then the info gurus can help you much better.
If If it is happening sometimes then your issue could be binding somewhere. If you have a belt drive then one thing could be the belt jumping on the gears in the tail. If you have a tt then you could be missing teeth on the tail gears.
Recheck your gear mesh if you have a tt setup. Poor mesh could cause the gears to jump and strip.
Sudden head speed change could cause this also. One way to find out is to change your normal curve to 0, 40, 75, 75, 75. This will give you a good spool up and then give a constant head speed at about 60% throttle. I have set this way and I like it a lot better. Now it's about collective management so I don't bog the motor. My idle up 1 is 75% straight across and iu 2 is 85%.
Without more info that's all I have for you. With a good video then the info gurus can help you much better.
murankar
Staff member
I have a mems gyro in my stock that will be coming off my protos mini. The gy 401b is a pezio gyro if I am not mistaken. If it is then temperature can effect the gyro and cause a constant tail wag until it reaches the same temperature as your environment. If you want the upgrade let me know and I can sell it possibly.
Graham Lawrie
Well-Known Member
Like Derek said wind can have this effect
The first time I saw this it was as if it was jerking and twitching due to an electrical fault. That was when I was told it was the gyro and wind effect. Vibration can have a similar effect
The first time I saw this it was as if it was jerking and twitching due to an electrical fault. That was when I was told it was the gyro and wind effect. Vibration can have a similar effect