monkeyking

Hi Goose
Can you please tell us if its safe to use the Cortex in HH mode on jets or not for normal flying??
People in some threads say that we DON'T have to use HH mode (http://www.rcgroups.com/forums/showthread.php?t=2258312)

I am waiting for mine to install it in my jet (Ultra Flash) and I don't see the problem to use it in HH mode for some maneuvers, like to do perfect rolls or knife edge...

Thanks.-

Bob_B

My Feedback: (11)

You can use HH mode, but I suggest you set only on axis of control at a time to HH mode and see how it feels to you. You will need to use the PC connection to do this.
I presently have my ailerons on bank two set to HH mode it works fine but it does feel different!

monkeyking

Thank you Bob for you response.
I did not see a video like this yet with a Cortex, https://www.youtube.com/watch?v=Q_-IMFKdMRc (it would be nice if some Cortex user can do it )

To respond to one of my doubts... that behavior is achieved in HH mode, isn't it??

Bob_B

My Feedback: (11)

YES in HH Mode

gooseF22

i concur with BobB

Ragz

I have been using the cortex since the last few days on a 100cc aerobat. Setup was easy. But I don't know how one can do slow rolls and point rolls using the HH mode. As we know the gyro fights the user inputs. It is happiest doing hovers and harriers in HH mode... nothing else. Atleast in the 6 flights i have had with my aerobatic plane this is what I have figured out. My normal gain is set at 12% and the HH gain is set at 50%...

I use iGyros on all my jets and I can do point rolls and slow rolls using that even on the FM3 switch (which is the HH mode). I think in the iGyro only the rudder is goes into HH mode...??

Falcon 64

So when the three position switch for flight-modes is used to control the Cortex, you mean the three position switch is centered in normal mode, and flipped either from or towards you to get take-off or landing mode, to correspond with the three settings on the Cortex, as off is in the middle?
I have my flight-modes like this, normal flight- switch flipped forward, landing mode in the middle and landing-mode flipped towards me.
I need to change this to normal flight is switch in the middle? About to learn a Jeti DS16, not quite familiar with it yet though..

Bob_B

My Feedback: (11)

Goose is using the flap switch as Flight Modes switch, you can set up 3 different gains on the Cortex. He also has a master switch that allows him to turn off the cortex too.

Falcon 64

Ahaa...☺
Many thanks!

Falcon 64

So in theory, I could have as many flight-modes as I want, and then just vary the amount of input for the Cortex on each of those flightmodes.
And switch it off with another switch..brilliant!
Not just default normal- off-heading hold, as a threeway-switch would do.

Bob_B

My Feedback: (11)

Exactly, you can even have selective heading hold on any axis by switching to bank 2 using the AVCS setting on a Futaba radio.

gooseF22

Exactly right.
The master switch/knob uses a mix Gain to Gain, of -100%.. so it mixes the output back on itself and nulls out the output to the gyro, and the red light will come on no matter what the actual mode/gain is.. Thanks to Jim McEwen for that mix.. If you are using modes or mixes to control gain, it gives you a specific way to kill the gyro in case you mix something bad, or if it came loose, or something like that..

When Im flying the early flights determining the gain, I have the gain on a knob.. Once that gain is determined for each mode, I lock them into the mode switch.. I flew all season last year like that.. the jeti radio will announce the knob percent, so its easy to know how much gain you are putting in.. sweet.

If you have too much gain, you will usually see it oscillate.. If that happens to you, gently load the plane, smooth pull up or something like that.. slow down, and reduce the gain.. a gentle load with the power back will load the flight control and have less gyro input.. gentle..

With smaller/foamies, big trainers.. big birds, in windy conditions, you may see it oscillate or fight the wind.. I flew it in my trojan in 25mph winds to test it.. the servos are slower, so it might not react well at times.. you can in that situation slow down the update rate with a computer.. then try again later.. I found that the stock settings work pretty well with about 40-60% gain in foamies max.. the stiffer the plane, the better the servos, the more gain it can handle in general terms, but the design of the plane factors in.. also what factors in is your expo setting.. the gyro needs a reduced setting .so when I set up a new gyro, I use a high and low expo.. take off in high expo, turn on the gain, then switch to low expo.. the feel should stay pretty consistent

have fun.. I have put the cortex in almost all my planes.. it makes even fun birds a hoot to fly.. Its interest to see a large trainer knife edge and hover.. lol..

Falcon 64

Useful and informative!
I ordered two with extra wiring from Esprit yesterday.

DEMONjoe

Obviously all went well....no further questions Let us know in case.

Quandry

Nice video and good way to explain it. I see a lot of folks saying "Don't try HH on your jet", is there really a problem here with the Cortex or will it perform the same if setup properly?

BarracudaHockey

My Feedback: (11)

Heading hold is strange if you've never used it before. If you are doing something like hovering and torque rolling its great. I personally (and i have a lot of experience messing with gyros) would not use it to fly around. If you try it, try it up high and be able to switch it off.

As for a comment above, the Cortex does NOT fight control inputs.

Harley Condra

My Feedback: (4)

Matt,
As I indicated in a different thread, Dustin set the gains on my "Fly Navy" KingCat while I flew the jet. It was very simple, and worked out perfectly!

qd25

Hi Guys
I'm waiting for my Cortex gyro it should be here any day now.I will run it in a Comparf 2 x 2 running 35cc MLD motor.
I have a question when you setup the gyro in the plane does the craft have to be level if so how do you determine when the plane is level ?
Thanks

BarracudaHockey

My Feedback: (11)

The gyro has to be level with the airframe. The gyro doesn't have to be level in reference to the ground while being setup or initialized. It doesn't know what "level" is in that regard.

qd25

Thanks for your reply. I'm still a little confused.
I found this setup video and at around 2.27 minutes it says that the cortex has to be level with the motor angle....I don't quite understand what he means

https://youtu.be/qFwcWuYXF2Q

JimBrown

My Feedback: (2)

I agree, a weird term to use. He's talking about the pitch axis.

When installing a 3 axis gyro, one wants to install it as close to the center of the aircraft as is practical, and as level as practical to each axis (pitch, yaw, roll.) It's not critical that the gyro be perfectly lined up with each axis, as they will tolerate a fair degree of error.

...jim

BarracudaHockey

My Feedback: (11)

Actually, its not that important at all for the gyro to be near the center, but it is important for them to be lined up with the axis.

qd25

I have just received my Cortex. So if I take my prop off and put a level on my prop shaft and line it up that way it should work ?
Thanks

siclick33

I think you're worrying a bit too much about the exact orientation. You just want it to be 'level' and perpendicular to the models axis.

The prop might have downthrust and sidethrust so you might not be any better off than doing it by eye. If you have a 'flat' servo tray with some spare room then put it on that. If not' just install it so that it looks flat and is square in the fuselage. Pay attention to the orientation shown in the manual and if you can't install it that way round then you will need to adjust the orientation settings using the PC cable.

gooseF22

its funny, you could actually install it on a wing tip and it would work properly as long as the axis were lined up close.. angular acceleration is the same no matter how far the distance from the center of rotation.. so just get it lined up best you can with the axis on X, Y, and Z. Like Jim said, it will handle a fair amount of error..