Demon Cortex Gyro question
 

I have the new Cortex gyro I want to install in my Skygate hawk. I am using spectrum failsafe receiver setup and I not sure about the connection. It shows to have a place for 2 satellite antennas. Do you have to use 2 of the satellites that you are using with the current receiver? Or do you add 2 more? Or are they not required? I don’t understand the reason for that conection.
Also what are you guys doing for the nose wheel and rudder with only one channel? I would think you use the rudder and not have it on the nose gear. Not crazy about using a y-harness but I would love to have it on the steering.
Last question is can you still use your dual rates and Expo with this gyro.
Thanks for the help

The Cortex provides you the option to use 2 Spektrum receivers but they aren't required. I could see them being useful in something like a simple sailplane that only needed 2, Ailerons, 2, elevators and a rudder. If you plugged in 1 or 2 Spectrum remotes in such a setup, no external receiver would be required.

If you're using an external receiver, simply don't add any Spektrum remotes to the Cortex. Just follow the setup guide and, for example, connect your right aileron to input channel A of the Cortex, and then plug your right aileron servo into servo port A of the Cortex. Just do that for all the channels you wish to stabilize.

Personally, I just installed a Cortex in the Skmaster small Hawk that I just completed. I added a JR G370A for the nose wheel steering. I considered using a Y harness or a Matchbox to match it to the rudder but I also wanted to be able to have a separate gain control for the nose wheel and to be able to disable nose wheel steering while the gear is retracted. Since I already had the JR gyro on hand it just seemed to be the simplest solution.

As for Dual Rates and Expo, yes you can still use them you will probably want to cut the expo in half or possibly eliminate it completely when the Cortex is enabled. On my other plane that I tested the Cortex in, enabling it made the controls feel like there was LOTS of expos. I have my transmitter setup so that enabling the Cortex automatically cuts the expo in half on all controls. I'll fine tune it from there after test flying the new plane later this week.

Also, when doing the setup procedure, make sure your dual rates are at the highest setting that will be needed for this airplane and that nothing binds at this setting as the Cortex uses these to determine it's travel limits when making corrections.

Awesome info. Yes I think i will add a serperate gryo for just the nose steering.

Do you think the Hood is needed on the turbine model. I have seen a few without it.

Thanks again for the help.

I believe the hood was for the very early versions that came out. If it is the later version, I don't think the hood is necessary.

George is correct about the hood. It's needed for the earlier versions which don't have the updated sensors. You should ba able to tell if your Cortex has the new sensors by looking at the edge of the circuit board. The newer versions will have copper etch saying bavarianDemon on the edge of the circuit board just in from of where the wiring loom plugs in. It can be difficult to see as the space between the plastic case and the connectors is very small but if you shine a flashlight down there and look very carefully you should be able to see it. If you don't have the latest version you will need to use the hush kit.

I just got it from Dreamworks this past week. I will look. Great info :)

It is possible to put the gyro sideways and use the two elevator channels for rudder and steering and the rudder channel for elevator? I only have one elevator servo
I have done this with the iGyro and it worked perfectly

I have 2 servos on the elevator. I just finished setting it up. I am going to use the knob to adjust the gain for the first flights. I have the travel set to off then to normal mode. I adjusted the travel so the hold side will not work. I lower it to 0 on that side of the travel for the channel I have the gain plugged into.

Any suggestions on first flights?

...

The CORTEX doesn't have 2 elevator outputs and 1 rudder output; it has 5 stabilised output channels and these can be any combination of axis. If you have one servo for nose steering, one for rudder and one for elevator, then you just plug them in and run the setup routine and you're done. It's really simple and there is no need to turn it on its side or anything. This will leave 2 spare stabilised channels which could be used for anything you want (but I'm guessing ailerons would be good).

The only thing to note is that each axis can only have one gain value, therefore the rudder and steering gain values will have to be the same, but this shouldn't cause a problem.

20-30% gain in normal mode should be ok for starters but you're always better off starting low and working your way up. I might be also tempted to have a switch to turn the gyro off for the first flights in case you knock the gain knob or something else happens; that way you can instantly turn the gyro off if you need to.

A few things to note when setting up the cortex gyro: red light the gyro is off... Amber light gyro is normal mode and green light is in hold mode...Also there is a new firmware update ver 14 (1.4).... This firmware will reduce a slight jitter on the control surfaces if you have any...

enjoy the best gyro on the current market......

Thanks LA guy and Slick. I am good to go on the setup now.

Thanks LA Jetguy. The jitter and oscillation disappeared after upgrading to V-14 !!!!
It's just great now !!!




Jack

LA Jetguy, where did you learn about the new firmware?
I wish I had known this before.


Jack

Are you referring to jitters at idle? or flying. I have no jitters just sitting still.

Jeff, this issue was extensively analyzed and debugged jointly with Danny and Joachim at Bavarian Demon.
Glad it's solved now. No need to go back to reviving fixed bugs.

Jack

Question about turning off the gyro in flight. Will there be a problem turning it back on during the flight, since the gyro needs to be "stabilized" - on the ground not moving to calibrate it before each flight?

Very helpful thanks. Didn't realise you could stabilise the steering in that way. I'm about to pop one in my Habu 32. Will definitely include the steering.

This is my third Cortex. I've never adjusted any settings via PC and have been very happy to date. The Cortex's aren't moved between models. Would changing the servo setting to digital allow higher gain? (Two of the three models have digital servos)

Alex

You are correct. Unit can't be turned off (there is no way to do it).
Gain can be made zero, though.

Jack... I'm part of Demonaero team.. :)


David..

Upsssss !! :) :)

I know David !! I regularly read your posts regarding Jeti and Cortex.

I guess the question should have been: How do we non team members find out about important bug fixing firmware upgrades ? :) :)

Jack

Sorry to jump in, but I installed it for the first time and noticed the jitters. Informed David and at the same time we both found the upgrade on their website after some research on the net. My "jitters" are gone now after the upgrade.

Enjoy

I have been playing around with bank two settings, I have been flying with the ailerons set to hold mode, elevator and rudder rate mode.
It gives the model a unique feel to say the least. I also set my trims to separate in the radio so when in hold mode the trim is "0". Otherwise the surface shifts.

Jack... Demonaero will soon have a page or link to all news, updates and FAQ... please visit www.demonaero.com