MSR with DX7 tuning

[bishop]

MSR Flys great, but during long forward flights after its gotten real fast msr will turn to the right and roll the right ? any suggestions ?
slow forward works great its just after it picks up speed it get out of control.
I have tried a couple tuning tips from youtube but its still rolling out of control.
thanks
bishop

[bishop]

so is that just the way the MSR flys ? there is no way to program out the right hand turn and roll at the end of a long straight flight across the shop?
its flying inside with no wind it should go in a straight line if tuned properly right ?

[xmech2k]

I think this is just the nature of the type of rotor it uses. If you read up on the development, history, and theory of helicopter flight, you'll see there's many problems to overcome. I think the MSR rotor is a simple (But amazing!) one that doesn't compensate for something like this. I'm at work so I don't have my MSR in front of me, but I'll guess the rotor turns so the advancing blade (The one going forward relative to the flight path) is on the left side, so when flying forward, it gets more lift, the retreating blade gets less, due to relative wind, and then you get the roll to the right. I'll have to check when I get home.

[SBMcGuire]

Your absolutely right. Because this chopper is fixed pitch it is going to have this characteristic. I don't know if this has been fixed with other FP choppers or if so, how, but in my RC inexperience, I don't know that there are any others that fly fast enough to even have this issue. I would imagine the fix would require an augmentation of the fusalage that doesn't effect slower speed flight. But I don't know of an easy solution as varying speeds require the the opposing effect be variating as well.

Originally Posted by xmech2k

I think this is just the nature of the type of rotor it uses. If you read up on the development, history, and theory of helicopter flight, you'll see there's many problems to overcome. I think the MSR rotor is a simple (But amazing!) one that doesn't compensate for something like this. I'm at work so I don't have my MSR in front of me, but I'll guess the rotor turns so the advancing blade (The one going forward relative to the flight path) is on the left side, so when flying forward, it gets more lift, the retreating blade gets less, due to relative wind, and then you get the roll to the right. I'll have to check when I get home.

edit: One other point I just thought of. The size of the MSR being so lite, plays a big part too. You probably don't have this issue at all with heavier aircraft because of the force required to cause it. The MSR doesn't need much force to cause anything as lite as it is.

[xmech2k]

Sorry I didn't get back on this earlier, but yes, the main rotor turns clockwise (Looking down from above) so the left side of the rotor disk is the advancing blade. It's all way more complicated than this, as there are so many forces involved, but this is what I guess is the main culprit. I'm not an aerodynamics expert, I just slept at a Holiday Inn.... No! JK! I'm just your average, over-the-top, aircraft geek who reads too much about this kind of stuff.

[SBMcGuire]

I haven't looked into how RC CP's work thoroughly yet but on a real chopper (for lack of a better term) the blades pitch independently which minimizes the excess lift of the leading blade. But the shear weight ratio is what keeps it from doing the same thing. Amongst other forces of course. I suspect gas powered heli's this problem so much.

But in the end who cares. Their fun as he11 and in many cases not too expensive compared to other RC hobbies.