Tail bob . . .

[papa-alpha]

I was having trouble with the tail bobbing up and down and learned from many friendly posts that the problem was head speed. I bumped it up and the bobbing stopped as predicted. The 500 is rock solid now.

I'm fairly new to all this. Question: What actually causes the tail to bounce when the head speed is too slow and why. I can't get my brain (such as it is) around it.

Thanks,

phil

[wbplomp]

I was having trouble with the tail bobbing up and down and learned from many friendly posts that the problem was head speed. I bumped it up and the bobbing stopped as predicted. The 500 is rock solid now.

I'm fairly new to all this. Question: What actually causes the tail to bounce when the head speed is too slow and why. I can't get my brain (such as it is) around it.

Thanks,

phil

It has to do with the center of gravity that is bumping up on one side. Also the blades catch a lot of air pressure, when they run to slow the blades may not get straight enough and it bumps everwhere the pressure is to high and the blades cannot straighten.

Sometimes when you make your heli nose-heavy the problem is also solved, no bobbing anymore. But that is not what you want. The T-Rex 500 just needs enough headspeed.

Another issue that may cause the bobbing is when your rotorhead is to tight. For example when you insert the new feathering shaft sleeve set (H500**) you need to increase you headspeed. I have noticed that with alu upgrade parts and this upgrade part you cannot solve bobbing with a 12T and 100% throttle, you need a 13T and at least 88% thrrotle.