You don't really want to fly a jet in HH mode

Why do you think that? Perhaps only ailerons in HH mode coulbe be good?

About the only real use of HH mode is to hover a 3D plane. Other than that, its a very different feel that most fixed wing pilots won't like.

I tried it briefly with an aerobatics plane and based on that experience I've completely disabled heading hold in my cortex. About the only use I can see for it is to enable it once your in a hover to let the cortex hover the plane virtually hand off. I've personally got no interest in that so I never use hold mode any more. I believe hold mode on the igyro is very different than it is on the cortex..

Hold mode is immediately disabled on that axis as soon as you move the stick away from center on the iGyro and reengages only when the stick is re-centered.

I'm not sure how to describe why, but flying a fixed wing around in hold mode on the Cortex, other than to do torque rolls, is a bad idea. Trust me I have a lot of experience with gyros, several of my articles are on manufacturers web pages for how-to info.

Thanks Barracuda, I will go in normal mode only :D

I don't know of a good explanation, but I will try.. its actually very simple in my approach.. never move anything more than 2 points at a time.. basically in the cortex, you can adjust the relative gains, and the stick priority. The relative gains can be adjusted for odd airplanes, for example a delta like a rafale, we had to lower the aileron and elevator gain by 2 points and up the rudder by two points, then try again.. we ended upping the rudder by 4.. what we looked for here was killing the yaw wiggle, but the gain got so high that it caused waggle in the wings too, so we made changes there.

Now for stick priority, this is more tricky.. first I need to make sure when you go messing with the settings have some way to kill the gyro.. the best way is a free mix... gain to gain with a value of -100 it will mix and null it..no matter what gain..

Stick priority: As you feed in stick, the internal damping of the cortex is reduced with the throw.. Its still working but not as much.. for instance: when you do a hammerhead and put full rudder in, the aileron and elevator damping is still trying to make it hold attitude.. If it isn't responding as aggressively as you like, then you can up the stick priority by 2 points in the axis and see if it has any effect

NOW.. the way I would do this is to copy banks so that its stock and factory on one side in attitude mode, and modified in the other.. this way you can switch back and forth simply by moving making your gain the same -40% vs +40% But this requires copying and modifying side 1 to look like side 0.. I don't use HH mode for an airplane... You can use it to hover, but I think it hovers fine with attitude mode.

So.. in an aerobatic plane, if the rudder seems a little mushy with the gyro, first of all, lower the expo by half the amount you have..but you can also learn it in low rates and use more gain, but then if you decide to play with the software you can up the stick priority 2 points at a time.. trust me when I say don't do more than that at at time.. It will result in an unbalanced feel..

Hope that makes some sense guys..

1. the stock settings work pretty good
2. If its mushy, then lower expo first, if its then mushy reduce master gain
3. If its wobbling a surface, lower the gain and relearn with that surface in low and the others in High (typically I learn Ailerons in low rate)
4. If its damping well and smooth, but doesn't seem aggressive enough and you need more on a single axis and can't get it by learning in high or low rate such as rudder, then you can add GAIN first inside the computer 2 points
5. If its damping well, Ie tracking smoothly and straight, but not aggressive enough when you bang the controls, then you can up a priority by 2 points on that axis.. Be careful with this..

Take a methodical approach and leave yourself an out.. I cannot emphasize that enough... we turned off the gyro several times on the delta wing we were setting up.. we eased up on it slowly.. hope that makes sense

I have setup my Cortex on a 3 position switch. OFF, then bank 1 = all (Ail,Elev, Rud) in NORM mode, and Bank 2 = Ail and Elev NORM and RUD in HOLD. I only use Bank 2 for takeoff or landing in a crosswind...it's helps with directional control. I agree with those that have mentioned that there is no real practical use for HOLD mode on a jet - its a 3D hovering type of function. If unfamiliar with gyros most people would find the feeling of HOLD mode really strange on a jet and need to bail out quick. Of course the other option I use in Bank 2 is = Ail and Elev NORM and Nose-wheel Steering in HOLD. This allows accurate runway tracking.

Goose,

Thanks for the explanation.. What you describe sounds a lot like what I tried but I never seemed to be able to get the stick priority quite the way I wanted. It always seemed that by the time I got the stick priority set so that the Cortex didn't fight me during extreme maneuvers, the plane started to feel "funny" in other ways. I probably just wasn't patient enough.

Thanks again.

When is reprogramming cortex necessary? I have to re-bind my RX, however no channel assignments have been changed, so do I have to reteach cortex? I have enjoyed the change in my jet since the installation, really being able to notice the difference during slow flight. I can't wait to continue tuning the jet and cortex the more I fly with it. I am looking to install them in all of my jets now.

Rebinding your tx doesn't mean you have to reprogram the cortex but its so easy to do if you have any doubts go ahead and do it.

This topic seems interesting and I have a Cortex still in the box that is going into a new plane that I have on the building table right now. I have iGyros in all my other planes and I am very satisfied with the way the iGyro works but just out of curiosity, I also wanted to give the Cortex a chance to find out what the differences are. The way I have set my gyros is always the same, when the planes feels mushy, funny or I can feel only the slightest way of me having to fight the gyro, reducing the gain has always helped.

The Cortex seems to have a very powerful software that has different options than the iGyro, let's see if being able to adjust the "stick priority" or the "locking in" really helps. Especially the "locking in" is something that I always wanted to be able to adjust manually, since the iGyro always has this tendency for the ailerons to swing a little before they actually lock in. Reducing the gain always helped, but if there's a parameter only for this, that definitely sounds promising.

I also do not know if the Cortex has the ability to use heading mode AND dampening mode together and set different gains but this is a function that the iGyro has and I like it a lot, even for jets. For example I can set 40% dampening gain for the ailerons but also have 10% heading gain in the SAME MODE. The elevators can have 30% dampening and 15% heading also in the SAME MODE. I have found that this helps improving the tracking of a plane even better without this "unnatural" feeling that you have to fight the plane.

So please do not misunderstand me. I am not trying to start a brand war here, I am just trying to understand the abilities of the Cortex in comparing to the PB products.

Thomas

Cortex is in either hold or normal mode and trust me, as a fixed wing pilot, unless you're trying to torque roll a 3D plane, you don't want it in hold mode

Please forgive me if this is a dumb question.....but......can I use the Cortex with my Airtronics FSSS-3 receiver?

Just want to know if it's compatable before I buy.

Thanks.

No problem. It will work great :)

Perfect, thanks!

When using the cortex with the spektrum DX18 gyro menu, do you just put the single gain channel in each of the 3axis? Does anyone have a video of the DX18 gyro set up with the cortex? I have used the gyro menu with the JR 370A. With this only working one axis there was no confusion. Thanks

When I flew DX back when, use the Flight modes. I used the flight modes on my flap switch so I used for example, 30% gain in flaps up, 40% in mid, and 45% in full flaps.. It also allowed me to trim each mode individually.. that I think is the best way for flap jets. For aerobatic planes, I used the same technique for low, med and high deflections but used common trim.

remember you are only changing the Master Gain.. the relative gain stays the same unless you get inside the cortex with a computer

Yep, just set it up on a switch, you don't need to fool with that gyro menu

There are a lot of things that are able to be done with the gyro menu. I have it on a 3 position switch already. I just would like to be able to utilize both gyro and DX18 to its ability. There is the ability to To curve gain master gain (priority) with the menu without having to go in cortex with a pc. Will just make a copy of the model and start playing around with it.

I have just fitted a Cortex in a new model with Powerbox expander and there seems to be a problem. All the control surfaces that are going through the Cortex are jittering slightly. I have read about the software update on early versions to solve this but this one is only a or so week old and Im assuming it has the latest software.. Not sure if it makes any difference but the Expander is set to 15ms.

Anyone got any ideas on how to sort it?

thanks
Jason

The surfaces will jitter slightly and I was told this is normal. As if though they are "nervous". I have 4 jets with the cortex installed and they all do the same thing. Check the software to make sure it's the latest (16).

I also have two other planes fitted with a Cortex but neither of them do this.

A slight amount of servo jitter is normal. This will vari with servo types but is almost always present to some degree. FYI, some PB and other servo distribution boxes don't like the higher frame rate the Cortex outputs when set to digital servo type. We recommend using the default anolog setting if you are using the Cortex between the RX and a servo distribution box.

There's been a lot of discussion on how to properly configure the TX for mode/gain control. A 3 position switch assigned to the aux channel is the simplist setup and is what most new users tend to go with. However, the gyro functions in many of the current generation TX's provide a lot of flexibility as well as reduced pilot workload. The bottom line is use what you are comfortable with. The Cortex doesn't care :)

Anyone have setup tips with Futaba18sz radio?
I am going to use it in a jet!

Thanks

TB