What to expect from HH

[Trailryder42]

I'm ready to try spooling up my 600E Pro with the gyro in HH mode. On the bench, the servo and blades don't center with center stick like they do in rate mode.

So how should I expect it to react as I spool up?

In videos, I see people move the tail side to side slightly while it's still on the ground. In addition to making sure you have tail control, does it get HH to center the servo and blades for going to hover?

[Blayd]

It wont center in HH with center stick. In HH, the gyro works from inputs.. it will adjust to the orientation from last position, and rudder input from you. When you lift off. it should hold the tail right where it is unless you give it input.

EDIT:::

You should make sure its working properly BEFORE you spool it up.. make sure its going to rotate the right way when you give rudder.. AND, that the heli will CORRECT in the right direction. If its not correcting in the right direction, when it lifts off.. it will spin, trying to stop the movement from its origin. Double check your gyro is working right when you give input, and that its correcting in the right direction. I dont "wag" the tail.. I check it before spooling it up.

[Bob O]

Trailryder,

Is this your first heli?

If not, it shouldn't be any different than any previous heli with a HH gyro in HH mode.

[McKrackin]

It doesn't center for a reason.
In HH,it maintains a heading.
It applies rudder as needed to maintain the heading.
If it is just sitting there,it thinks no adjustment is needed.

Pick it up and rotate it. The tail slider should move the opposite direction as the boom.

[Trailryder42]

Thanks guys. Yes, first heli.

Input direction is correct, as well as correction direction. I'm versed on how it works, Just wanted to know what to expect from it that first lift off.

Sounds like, the instant the heli lifts off the ground, if there's any deflection, THEN the gyro corrects the tail to run true.

Not like in rate mode where I would need to be ready to give some input to correct it if it wasn't setup perfect on the bench. Sort of like, knowing that as soon as it lifts off it's going to want to drift left(at least it does in the Sim), so I need to be ready for that.

[Blayd]

Yeah, the tail should be pretty stable at lift off...the cyclic is what you want to be vigilant on when you lift off..
Now, if for some reason it drifts or wags.. that could spook you on the first lift off.. but just be calm and be ready to make SMALL adjustments until you get used to it. The drift to left on take off becomes second nature after a bit. I dont even notice it anymore...

[Trailryder42]

Originally Posted by Blayd

The drift to left on take off becomes second nature after a bit. I dont even notice it anymore...

Yeah, I agree. In the sim, it's automatic that I compensate for left drift as it lifts off.

I have my cyclic and rudder expo set to -20% to start off with.

[Blayd]

-20%? I think you want +20% for expo. Negative expo makes things more sensitive at center.

[McKrackin]

Originally Posted by Blayd

-20%? I think you want +20% for expo. Negative expo makes things more sensitive at center.

That depends.
+expo softens JR and Spektrum
-expo softens Futaba

[Blayd]

(Walkera is + too..)
Yeah, I was just going to edit that.....I forget about the Futaba factor... thanks.

[MarkD]

People wiggle the tail before lift off to center the tail. I flick from HH to rate then to HH. If you don't the tail will try to move back to where you had it on startup. Ie the heli is facing south after bootup and servo checks. You walk to the flightline but the heli is now facing North. As soon as ground friction is overcome the heli will spin round to the south - most likely nose in. Wiggling, switching modes resets the gyros orientation.

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[Trailryder42]

Originally Posted by MarkD

People wiggle the tail before lift off to center the tail. I flick from HH to rate then to HH. If you don't the tail will try to move back to where you had it on startup. Ie the heli is facing south after bootup and servo checks. You walk to the flightline but the heli is now facing North. As soon as ground friction is overcome the heli will spin round to the south - most likely nose in. Wiggling, switching modes resets the gyros orientation.

I hadn't thought of that. Well described scenario. Thanks Mark.

So I need to figure out how to set up a switch on my 8fgs so I can switch between rate and HH.

[MarkD]

You don't need to set up a rate and HH SW, just wiggle the rudder just before lift off to give the gyro a new heading. I only do it my way because that's how I have done it since HH gyros first came out. I also set my tail up mechanically in rate mode first so that it holds

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[Trailryder42]

Originally Posted by MarkD

You don't need to set up a rate and HH SW, just wiggle the rudder just before lift off to give the gyro a new heading. I only do it my way because that's how I have done it since HH gyros first came out. I also set my tail up mechanically in rate mode first so that it holds

Thanks. I set mine up in rate mode too.

[Trailryder42]

I just ran it up on the flat 30 curve, 0 pitch. HH mode. The tail is drifting right sitting on the ground. Don't know what to make of that.

Gyro gain is set at 75 in my 8fgs. I have the right dial switch set to allow a 10% adjustment in either direction. So I have a gain range from 65-85 % that it was still drifting with.

I would correct it with stick input, only to have it start drifting again.

I'm afraid to put more than a few degrees of pitch in the blades because of a concern that if it's drifting on the ground, it will spin in the air.

[Bob O]

What's with the wiggling and centering of the rudder before take off?

I've always just carried the heli out, set it down where the tail blades won't scrape the grass, and spool up.

[McKrackin]

Originally Posted by Bob O

What's with the wiggling and centering of the rudder before take off?

I've always just carried the heli out, set it down where the tail blades won't scrape the grass, and spool up.

You're probably like me and just grab hold of the tail on spool up and never even notice.

[Bob O]

30% power won't get the head speed/ tail speed up high enough where the tail rotor has any decent amount of authority to do much of anything.

Here's what I would do. If you have the tail built correctly, the tail servo moving in the correct direction, have gyro compensation in the correct direction, and your gyro in HH, then spool it up to 70% throttle (minimum) at mid-stick. The heli should not be rotating or spinning at all by that point. If it does, something is not built or setup properly.

[Trailryder42]

I'm setting this heli up to fly scale.

In gov mode, throttle curves are flat 30, 70 and 100. At the flat 30 I got a head speed of 1958rpm. On the 70 curve I got 2010rpm. Both of those are within 5rpm of what the Castle ESC is set for. (Using the Helitach App on the iPhone. )

I didn't leave the heli running at the flat 70 very long because it spooked me when I switched up to it, the torque spun the tail quite a bit, so I didn't see if the tail was drifting with that head speed.

I probably need to reprogram the ESC for a slower head speed change.

If the flat 30 curve and the 1958 head speed isn't enough drive for tail authority then I guess it's pretty much useless as a flight mode. I guess that's why it's doesn't seem to be much of a concern with people, loosing it when enabling auto rotation in the ESC.

[Trailryder42]

Originally Posted by Bob O

Here's what I would do. If you have the tail built correctly, the tail servo moving in the correct direction, have gyro compensation in the correct direction, and your gyro in HH, then spool it up to 70% throttle (minimum) at mid-stick. The heli should not be rotating or spinning at all by that point. If it does, something is not built or setup properly.

I set up the heli and my pitch curve so that at center stick I have +5* of pitch. Since hover is right about there, I'm not ready to run the stick up that far yet with the tail doing this.

I recorded a test video. I'm converting it for up load and will have it up shortly.