What is phasing?

[Maxists The Baddist]

What is phasing?

[DebianDog]

In regards to what?

[Maxists The Baddist]

When talking about the rotorhead and blades?

[ClayK]

I think it has something to do with timing blade positions/swash position on multi-bladed heads/flybarless setups.

[AV8TOR]

What is phasing?

You got that phrase from Swift-Tuning didn’t you?

[BarracudaHockey]

Phasing is the relationship between swashplate inputs and the rotor head.

For example on an EVO if the cheap plastic radius block slips and the head becomes 20 degrees out of phase then an aileron input on the swash plate would result in an lesser aileron input and some degree of elevator input. Some heads allow adjustable phasing so that if every time you roll your heli you get some nose pitch up or pitch down you can try to tinker with it to get a pure roll input.

That being said, Ben Minor says that if you spend the time to adjust phasing for one manuver it usually makes it worse for something else.

[Maxists The Baddist]

I didn't know that. I though it might have something to do with tracking. Here's my problem. My blades went way out of track and got that woof sound that I read about. Tried to land and chopped off my tail. I know two things were happening when this happened. First, the auto-hub on my rap50 was locked, which I've read shouldn't matter. Second, I may have over tightened my gripes. Could over tightening the grips cause this to happen?

[BarracudaHockey]

The phasing on the Raptor, unless you have a 3rd party head, and even in only some cases there, I have QUK head, isn't adjustable.

You had woof and poof.
There's several known causes, slop in the head, bent screw holding the ball to the blade grips, slop in the collective system, radial bearings loose in the grips, thrust bearings installed incorrectly among others.
http://www.raptortechnique.com mike has a whole page on it.

[ClayK]

Could be a variety of things. Head block, dampeners, weak servo, etc etc

[DebianDog]

OR a Raptor V1 ;)

[jschief]

I had to regrease the thrust bearings in the head block for my raptor for the woof effect to go away.

[vera]

What is phasing?

When it's running, the direction of the tilt of the rotor disk should follow the direction of the tilt of the swashplate. If it doesn't, then you have a phasing error. So for example, if you move the cyclic pitch forward, the the swashplate tilts forward and the rotor disk should tilt forward, and if it tilts by any amount to the left or right then you have a phasing error. I think of it as direction pollution.

You can check this with the engine off. Park the blades in a left/right position and move the TX cyclic left/right. The pitch of the blades should not change at all. Or, park the blades fore/aft and move the TX cyclic fore/aft and the pitch should not change at all. If that seems odd, remember "gyroscopic precession"; the reaction is delayed by 90 degrees.

You can get the phasing pretty close by eyeballing the flybar... setting it in a fore/aft position as best you can - parallel to the longitudinal axis, then check the balls on the inner and outer parts of the swashplate; they should line up.

On some helis you can't do anything about it. Raptor 50 can't. Others have a guide that clamps to the drive shaft and it can be adjusted. Sceadu and Caliber 30 can adjust. The washout levers have to spin on the shaft and also be able to move up/down on the shaft. The washout levers are what spin the inner swashplate star. You can notice some guide pins that capture the washout levers and spin it. Those pins come right out of the head on the Raptor and there is no adjustment to it. On the Caliber, for example, there is a block that grips the shaft and that's what has the guide pins which capture the washout levers and they drag the swash inner star around. If that block isn't properly adjusted then there will be a phasing error.

When hovering, if the heli moves forward/backwards when you move the cyclic left or right, or if it moves left or right when you move the stick forward/backwards, there is a phasing error. You can see why I call it direction pollution.