Bavarian Demon Cortex

A 3-axis stabilization system for fixed wing model aircraft.


This gyro for your plane can tame the wind and make your plane feel bigger.

Bavarian Demon Cortex
Manufacturer:Bavarian Demon
Available From:3D Hobby Shop
Street Price:$349

Gyros are for helis only right? Now they are also for planes. I was in a discussion with Ben Fisher of 3D Hobby Shop last year at SEFF and he was telling me that there were some interesting new developments in gyros for planes. I have been keeping my eye out and found the Cortex by Bavarian Demon.

In my video I show you how I set up the Cortex and in this review I will go over the steps. The video also features my plane flying with the Cortex gyro.

Bavarian Demon Cortex RCGroups (16 min 47 sec)

The CORTEX stabilizes all three flight axes with its three gyro sensors: aileron, elevator and rudder. Bavarian Demon uses the technology of the HeliCommand/bavarianDEMON X-series and modified it to fit fixed wing aircraft.

Adding a gyro to your plane seems like it would be complicated. I have never set up a gyro and the task seemed a little daunting. The great news is the whole process is very simple.

Why would you want a gyro for your plane? Here are some good reasons:

  • The gyro smooths out flight characteristics.
  • High winds are tamed with the gyro.
  • New pilots can learn faster with a gyro.
  • The gyro adds precision.

Up to 5 servos/channels can be used with the Cortex. If the number of channels is not enough servos can also be connected via Y-cables,

  • Supports up to 5 channels:
  • 2 ailerons, 2 rudders, 1 rudder
  • 4 ailerons, 1 elevator

What does the Cortex come with?

  • Main sensor unit including mounting pads
  • Cable loom for receiver connection
  • USB lead for direct connection to PC / Notebook
  • Jumper for programming

Installing the Cortex

NOTE - Be sure to remove your prop while installing and testing the gyro. Your throttle servo/ESC does not connect to the Cortex.

Your plane needs to be setup up before your install the Cortex. Make sure all control surfaces are moving the right direction and assigned to the right channels.

Turn dual rates off.

Connecting the Cortex

The servos to be stabilized are connected to CORTEX’s outputs A to E (bottom). The same assignment applies to the input side going out to the receiver. Cable A through E on the receiver corresponds to slot A through E on the CORTEX.

Mounting the Cortex

Mounting the Cortex correctly is very important. Use the thin adhesive pad for electric planes and the thick pad for glow or gas planes.

The socket side should be facing the nose of the plane. All axis of the Cortex must line up with the planes axis. You should also make sure the Cortex is level.


Plug in the jumper supplied as shown in the illustration, then power on the device. Have your transmitter ready for inputs and your quick-start guide in front of you. After you plug in your battery you will see 2 red LED flashes.

Here is an image explaining the LED flashes and what you should do:

Pull out your bind plug and turn power off.

When you plug your plane back in be sure not to move it for 6 seconds. This lets the gyro initialize. You must follow this startup procedure every time you power up your plane.

Here are the meanings fo the LEDs after you power your plane back up:

Gyro Channels - Switch

You control your gyro states through a switch. After I set mine up the Aux 1 switch was already working. Up is Normal mode, middle is Off and down is Hold.

Setting Your Gains

I go over this in my video. Gains are set by changing the end points of your switch. You should start at 15 for your Normal mode and 30 for your Hold mode. I ended up at 20 and 40. Each plane is vastly different so you will need to try your Cortex out at different values to find the right end points.

Gyro Directional Test

This step is definitely required before your first flight. I go over this in my video.

Tilt the model in each axis and check that during the movement the corresponding rudders deflect in the opposite direction, i.e. work against it. Check both directions for each axis.


When using the gyro there is very little need for expo. I test flew my plane with Jason Cole. He felt the plane needed no expo when the gyro was on. I like my controls slightly soft around the middle so I added back in some expo. That is up to the pilot's preferences.

We took off and made sure the plane was trimmed up and then went to Normal mode. You can see in the video that even at 15% the plane smoothed out in the hard wind. At 30% gain in the Hold mode we were able to hold a harrier and hover. I landed and increased the gains to 20 in Normal and 40 in Hold. The change wasn't dramatic but you got a better idea of what the gyro did.

Normal Mode

When you get everything set up you can leave your plane in Normal mode. It doesn't fight you, it just makes everything feel smoother. It also aids in take off and landings. It is like you are flying on rails. It is also described as making a small plane fly like a big plane. My Lamyak 60 is an awesome plane in general so I wondered if we would really feel the effects of the Cortex. The change it made was to help in the wind and made the plane easier to fly - which is a huge accomplishment in a plane that always flies like a big baby.

Jason Cole has flown just about everything and was into profiles like the Lamyak in the early days. While test flying the Cortex he repeated the words "awesome." He also said this would be a great tool to use to learn to fly. I asked him if the unit was worth the asking price and his response was "definitely."

Hold Mode

As the video shows Hold mode was good for not only hovering but also for harrier. It would lock the the plane in. The Hold mode did fight your inputs to keep it in place. The only thing you have to worry about is the throttle. I have seen videos of planes in Hold mode when the plane hovered while the pilot put the TX on the ground. I'm not sure I'll be doing that but it's interesting to note.

Overall Impressions

When I read about the Cortex I had to try it. The guys at Demon Bavarian were very confident in their system and now I know why. Since I had never worked with a gyro before I was a little intimidated by the setup but it was easy once you knew the steps. I did one setup and then we were flying it an hour later. It was no big deal. While the Hold mode is impressive it is the Normal mode that is the winner. Like Jason said, "I don't know why you wouldn't fly it in the Normal mode all the time." It's going to stay on the Lamyak (my favorite big plane) and now I know that wind is no longer a barrier to flying. I'm a big fan of the Cortex. If you get a chance to try one be sure to do it!

Learn more about the Bavarian Demon Cortex here.

You can purchase the Cortex from Esprit.

Thread Tools
Mar 27, 2014, 11:48 AM
yank and bank!!
He sure holds his tx funny
Mar 27, 2014, 01:11 PM
Registered User
$$$$ How Much? $$$$
Mar 27, 2014, 02:20 PM
Registered User
Originally Posted by wahrhaftig
$$$$ How Much? $$$$
Website shows a price of around 250 Euros which converts to about $350 with today's exchange rate.

A bit pricey but if you crash a lot.....
Mar 27, 2014, 02:23 PM
Admin Deluxe
Jim T. Graham's Avatar
Thread OP
I have added the price and a buy link.
Mar 27, 2014, 03:24 PM
Registered User


I'd go for a Guardian or HK, obviously. If they're going to sell these, they'd have to have significant advantages over their much cheaper competitors.
Mar 27, 2014, 08:36 PM
Tim H.'s Avatar
Originally Posted by gregory smith
I'd go for a Guardian or HK, obviously. If they're going to sell these, they'd have to have significant advantages over their much cheaper competitors.
First let me say "great write up Jim!"

Now... Its worth EVERY penny! I have several different Helicopter and Airplane gyros. The only one I have not flown is the HK. The Cortex is light years ahead of the others. I am messing around with the Hyperion one right now and while it's not a Cortex, it's better than the others.

The Demon Cortex gyro is in a class by itself and traces it's roots from a VERY good flaybarless system. There is a lot of technology and thought that has gone into this.

The Cortex is very hard to describe. It won't make you a better pilot (per se), but it will help you get better by allowing you to concentrate on flying, and not fighting the plane. It does not hinder anything either, which is nice.

The best way I can describe it is it's like going from black and white TV to full 1080p on a 72" screen. It's like spraying a coat of "smooth" on the plane. It's just better... It's almost hard to put it into words.

All I can say is if you have a chance to try it, do it! Is it cheating, well, no... It's a tool. Use it that way and think of it that way and you'll be rewarded with absolute joy!

Is it going to teach me rollers? No... But it will help me with the confidence to bring them lower and with a much better sense of control and "connection" with the plane.

There is a Cortex Thread in the 3D Planes forum that is fairly active with most of the major questions being answered. As far as I know, EVERY person that has tried one, has nothing but glowing comments. As a side note, I am in no way affiliated with this product or the sales of this product. Just a VERY happy customer.

Here is a quick video I did the other day. I'm not an expert 3D pilot, but it took the way my 3DHS 74" Edge flies from great to spectacular!

3DHS 74" Edge 540 Electric + Bavarian Demon Cortex (5 min 49 sec)
Last edited by Tim H.; Mar 27, 2014 at 08:44 PM.
Mar 31, 2014, 11:18 AM
RIP Azarr - "Old age is not for sissies"
Azarr's Avatar
I've read the other thread and indeed everyone that tries it seems to think it's worth the value. It does seem like the manufacturer needs to do a better job of explaining the actual differences between something like the Eagle Tree and the Cortex and why it's worth the $$$$$ difference.

I'm on the fence at the moment, but thinking hard, I think the ability to program the gain proportional to the stick movement and set a delay for it to kick in again will push me over the edge. I've got both the Eagle Tree and the HK receiver combo and am running a mix to shut them off for a violent maneuver because they dampen the action too much.


EDIT: BH: can you add the spm file for your DX18?
Last edited by Azarr; Mar 31, 2014 at 11:23 AM.
Mar 31, 2014, 03:59 PM
Multi-Platform Pilot
barracudahockey's Avatar
I've flown almost all the stabilizers on the market and this one is hands down the best.
Apr 01, 2014, 09:50 AM
3drcparts's Avatar
I was sceptical at first, but loved them so much I became a dealer, they are simply awesome. here is a video of me flying the beast without and with, I think you can easily see the benefit in harrier on a plane that used to scare me down low, I now love putting full packs through 5 feet off the ground

E-flite beast 60e (2 min 59 sec)

with the cortex
E-flite beast 60e with demon cortex gyro (6 min 10 sec)

Ole at
Last edited by 3drcparts; Apr 01, 2014 at 09:51 AM. Reason: spelling
Apr 01, 2014, 10:08 AM
Where'd it go? Uh Oh!
capngrog's Avatar
The Demon Cortex is, without a doubt, cool. Are these allowed to be flown in competition? If so, who gets the credit for the flight ... the pilot or the Cortex?

Just askin',
Apr 01, 2014, 10:11 AM
Multi-Platform Pilot
barracudahockey's Avatar
Depends on the competition.
Apr 01, 2014, 10:43 AM
RIP Azarr - "Old age is not for sissies"
Azarr's Avatar
Originally Posted by capngrog
The Demon Cortex is, without a doubt, cool. Are these allowed to be flown in competition? If so, who gets the credit for the flight ... the pilot or the Cortex?

Just askin',
If you look at our history you'll see people were saying the same thing when Expo was introduced.

Apr 01, 2014, 12:54 PM
Home of A-10 - Farmingdale NY
boiko's Avatar
If you have a larger plane and/or the money, go for it..looks great.

If not, then there are plenty of other alternatives for a fraction of the price.

Last edited by boiko; Apr 01, 2014 at 01:08 PM.
Apr 01, 2014, 06:01 PM
Where'd it go? Uh Oh!
capngrog's Avatar

I wasn't making (saying) a statement about the Demon Cortex, I was asking a question. If the question was asked about expo, what was the answer? I understand how mixes, expo etc. are an enhancement to the hobby, but sooner or later, the question must be asked: "Who is flying, the computer or the pilot". Once this question is addressed, it must be determined at what point and to what extent computer-enhanced flying/piloting is allowed in competition. Some believe that computer enhanced flight stability would be an aid in learning to fly. I agree, up to a point, but once the new pilot is past that point, I believe computer enhanced stability would retard the learning of basic flying/piloting skills.

By the way, the same question, albeit posed in a different context, is being asked in the full-sized aviation community. Some notable recent airline crashes were apparently caused by pilots' over reliance on automation. The airline community is also quite concerned by a perceived degradation in pilots' "stick-and-rudder" skills due to over-reliance on automation.

Just askin'/sayin',

Quick Reply

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold Bavarian Demon Cortex USB Cable -NEW Dave Grife Aircraft - Electric - Jets (FS/W) 2 Nov 09, 2015 04:05 PM
Sold Bavarian Demon Cortex USB Cable -NEW Dave Grife Aircraft - General - Radio Equipment (FS/W) 0 Nov 08, 2015 05:08 PM
Sold Bavarian Demon Cortex - Like New dtmtoyz Aircraft - General - Radio Equipment (FS/W) 1 Oct 26, 2015 10:56 AM
Sold Bavarian Demon Cortex Hinckley Bill Aircraft - General - Radio Equipment (FS/W) 0 Oct 17, 2015 09:05 AM
Sold Bavarian Demon Cortex racerboy65 Aircraft - General - Radio Equipment (FS/W) 1 Oct 03, 2015 11:47 AM