I have to admit to being disappointed with my Cortex feeling I have been misled. Before purchase I emailed Demon to ask if it was compatible with the 18MZ Robbe 2018 and sBus, the reply was "yes". Shortly after unboxing I find it has no sBus output which if used would totally negate the principal of sBus.
i spoke to the factory guy at Jetpower who told me it would be 12 months for them to drag themselves into the twenty first century!

This has been discussed in a couple Demon threads (maybe even this one). The use of a SBE-1 might be a work-around, but not sure anyone has tried it yet. I know Bob_B was going to try it out, just don't know when. I'm also going to try when I return home as I have two sBus equipped planes I'd like to try the Cortex in.

Sorry to hear that you're unhappy with the Cortex but I think that 'being misled' is a tad harsh; it sounds to me like a simple error in communication. The Cortex is S-Bus compatable in exactly the same way that a SBD-1 decoder is and many people use it in S-Bus systems, and it will work with the 18MZ and Robbe 2018 as they told you (just not in the way you want it to). As you correctly state, the Cortex doesn't have an S-Bus output and I'm sure if you had asked that question they would have explained the output limitations (as has been discussed already here in detail).

It is still a very good gyro if you can work around the lack of S-Bus output. If this is a critical feature then if you speak to Bavarian Demon (or whoever you purchased it from) and explain your disappointment then I am sure they will look after you.

Jeff, transparent is exactly how the cortex performs, good to hear you like it.

Craig thanks for the post on your cortex experience. I know you're demanding about the gear you install in your models.

Depending on how your electric test plane was setup ie: "y" harnesses could part of the problem you are having. You said you plugged in the jumper and watched the the gyro go through its steps, if you do not move the sticks once in programming mode the gyro will ignore any of those channels that are plugged in. As Wayne suggested check the basic radio setup, then reintroduce the gyro to the install. Here to help, just let me know,
Bob

Hi guys,

OK all well but I cannot switch between Bank 1, Off and Bank. I can only switch between Bank 1 and Bank 2. So the only way to switch off the gyro is to set Bank 2 to off using my PC. So now when the Orange led is on, the gyro is working and when the green led is on, the gyro don't work.

Another question I have, is how do I control gyro gain from my TX?

Gyro has been update to v15 using latest software on my PC.

What am I doing wrong?

Jan

It is also incompatible with CAA requirements (twin Rx input) another request for information answered incorrectly. I remain interested to understand how to integrate the Cortex into the 18/2018 setup and at witch point does the PWM output become sBus!

m

Apologies if I'm wrong but I believe that the Robbe 2018 has an S-Bus output. The Cortex can therefore be supplied with an S-Bus signal after the Robbe 2018 and the servos would be supplied with PWM from the Cortex. As stated earlier, the Cortex does not have an S-Bus output. The Robbe can be supplied with 2 receivers which may or may not satisfy the LMA (I would need to ask an inspector to be sure).

If you remain unhappy then please contact Bavarian Demon and explain to to them. They are good people and I'm 100 per cent sure they haven't intentionally supplied false information; that would not be in their interests.

You need a 3 position switch on the gain channel (or a variable knob). When the travel value of the gain input channel is at zero then the gyro gain is set to zero (i.e. off). Varying the value of the switch endpoints will vary the gain.

How many gyro channels do I need? I thought the only one is the Aux one? So in simple language, I have 5 leads plugged into 5 servo positions on my Rx - two ailerons, two elevators and one rudder. Then I have Aux plugged into a seperate channel - this is the only gyro channel from what I understand. So where do I get a gyro gain channel from?

Jan

The Aux channel is the gyro gain channel. Varying the value of that input varies the gain, on one side of the travel it is in bank 1, on the other side it is in bank 2 and with a zero input the gain is zero (i.e. gyro off).

I hope that makes sense.

Jan,
You only require 1 channel to run the gyro. You may be 'over thinking' it all.
You need a 3 position switch if you want to use both banks (Or 2 different gains in the same bank) AND have an 'off' switch. For example:

Switch position A = OFF,
Switch position B = Bank 1
Switch position C = Bank 2

You could also just use one bank. For example:

Switch position A = OFF,
Switch position B = Bank 1 (20% Gain)
Switch position C = Bank 1 (40% Gain)

It's completely up to you. If you only plan on using 1 bank and you don't need 2 different gain settings, then you could just use a 2 position switch. For example:

Switch position A = OFF,
Switch position B = Bank 1

You mention above that you can't turn it off??? Check your servo travel page on your TX that it is actually going to 0 (zero). Anything other than zero, will mean the gyro is on.

Also, If you are interested in changing the gain whilst flying, you need to setup a switch which changes the travel on your GYRO CHANNEL.

Clear as mud???? ;)
Cheers,
Morten

OK got it. Had to take the aux from my ch14 to another as it only handles 0 to 100 % switching.

I have the default gain settings at the moment. By varying the end points on my gyro channel I can reduce the gain from 82%t to 3% (as per my PC display when I move the gyro channel on my TX) - this is obviously the % gain within the default setting on the gyro - right? Should I reduce the end points on my TX to reduce to 82%?

The 2018 has four sBus outputs and two receiver inputs satisfying the CAA requirement, the Cortex doesn’t slot into the system at anypoint. The iGyro for instance slots in between the Rx’s and the power expander,the Cortex cannot do this. It seems to me they have ignored the full extent of the sBus system or misunderstood it, the people on the Demon stand at Jetpower admitted these shortcomings, reluctantly, and said the full compatible system would take a year to come to market!
I am only disappointed with the response to my questions,not with the gyro, the gyro will be used in another of my models, an Airworld Hunter which is all PWM and under 20Kgs. I’m only pointing this out to forwarn anyone else who may be under the impression the Cortex is fully sBus compatible.

m

I'd look at the igiro e due in December, Cortex eater!

[QUOTE=Springbok Flyer;11889872]OK got it. Had to take the aux from my ch14 to another as it only handles 0 to 100 % switching.

I have the default gain settings at the moment. By varying the end points on my gyro channel I can reduce the gain from 82%t to 3% (as per my PC display when I move the gyro channel on my TX) - this is obviously the % gain within the default setting on the gyro - right? Should I reduce the end points on my TX to reduce to 82%?[/QUOTE

What Tx do you use?

Hi Bob,

I use a Futaba 18MZ and Futaba 14 ch RX. I took the aux out of the 14ch on the RX and put it into ch11. Now the 3 way switch is working and all I wish to confirm, is that if I reduce the end points on ch11 that I will end up with that % gain as the % of whatever the gain setting is on bank1 and bank2 in the gyro.

Jan

Jan,
Yes, that is correct, the higher the end point value, the higher the gain for the associated bank and since the scale is 0% - 100%, gain should match the end point values very closely. However, I don't think you have any need to worry about values near the high end of the scale as you will never be able to run your gains anywhere near that high of a value. If i recall correctly, the setup guide recommends starting with a value of 20% in normal mode or 40% in hold mode. I don't personally use hold mode as it is best suited to hovering, etc, but in normal mode, I never get above 30% gain before oscillations begin. The amount of gain you will be able to use will be affected by servo speed and precision, airframe vibration, linkage slop, control surface size, etc. Start with a low value and work your way up. You'll be amazed at how locked in the plane is with a relatively low gain value.

Thanks Bob, that could be it…. I will try it. Although I think I was putting them in one at a time and testing to see that they worked before the jumper came into play.



Another vote for S-bus! I have three Robbe 2018's, and a few power boxes that are S-bus. The srs has the igryo, but the others don't. Just programmed the nodes for a comp arf P-51 last night, one wire going down the fuse to address five servos is too cool :-)

Let us know what you find out.

What would be really great is if the cortex had a stick priority mode, where the gain would be progressively reduced with more stick input. Like you can do with individual gyros each having its gain channel controlled by the flight channel it is stabilizing

Bob, it has that and its adjustable with a pc

Wow,
Really? I'll have to connect it to my pc and set that up. Thanks!

There is no need to reduce gain to maintain control authority. Normally, nothing more than reducing the expo on a channel is needed to give you the feel that you want. The Cortex doesn't fight your inputs the way gyros of old did. For example, the roll rate of the airplane at full stick deflection isn't reduced when the Cortex is enabled, regardless of gain. Still, there are settings that can be tuned with a PC to tailor the "feel" to better suit you if you can't get it quite the way you want by reducing / eliminating expo.

Hello Wayne,

When oscillations begin, does it happen only on one axis or all. what if we need more gain on ailerons and less on elevator. whats the correct procedure for setup.

Thanks
Chatty.