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Demon Cortex Gyro question

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Old 09-09-2014, 12:54 AM
  #51
c_makhija
 
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I always was under the impression, the I gyro is the best on the market, but looks like the cortex is a winner. Is it only due to price or performance too?
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Old 09-09-2014, 05:40 AM
  #52
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Quote:
Originally Posted by c_makhija View Post
I always was under the impression, the I gyro is the best on the market, but looks like the cortex is a winner. Is it only due to price or performance too?
I think whether the iGyro or Cortex is "best" is a rather subjective decision as both seem to be excellent gyros and have their strengths. Some may feel the iGyro is best because it uses GPS to reduce the gyro gain as speed is increased, allowing you to run at the maximum gain setting at all speeds. Personally, with my Cortex, I simply flew as fast as possible and adjusted the gain, via a knob, until I could see the model just start to hunt and then immediately backed off the gain a few percent below that point. To be honest, once I adjusted the gain, the plane felt so well locked in that I saw no need to increase the gain at slower speeds. Depending on the plane, servos, etc, others may have a different experience. While I've never flown an iGyro, I've used a number of different gyros in helis and the Cortex works so well, I can't imagine the iGyro being a significant improvement from a performance perspective. So in my opinion, no, it's not just the price, the Cortex appears to be on par with the iGyro from a performance perspective as well.
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Old 09-09-2014, 05:57 AM
  #53
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The jet that I plan to put my Cortex into is curretnly set up with a SmartFly EQ-10. I have two elevator servos going into one input on the SmartFly then into a single input on the receiver. The ailerons are set up the same way. The smartfly acts as a matchbox in this configuration. My question is, can I use the Smartfly with the Cortex at all, and if so, would I have to seperat the elevator and aileron servos on their own input to the smartfly then into the Cortex?

Mark
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Old 09-09-2014, 06:08 AM
  #54
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Mark, if you are not reversing any of the servos through the smart fly it should work. Install the gyro between the RX and the Smart fly unit. Can you have separate inputs from your RX to the Smart fly for each channel? If so I would suggest that and then move the gyro between the Smart Fly and servos.
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Old 09-09-2014, 06:29 AM
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Bob, Thanks for the response. Glad to hear that they are compatible. I will give it a try and see how it works out.
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Old 09-09-2014, 06:39 AM
  #56
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Please verify everything works as you expect.
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Old 09-12-2014, 04:27 AM
  #57
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Quote:
Originally Posted by Harley Condra View Post


The gyro is plugged into AUX 2 on my 12X, and selecting "GYRO" in code 17 on AUX 2, gives you control of code 44, so the gyro sensitivity is adjustable in all three flight modes. My sensitivity settings are: Flight Mode 0 (Gear Up, Flaps Up, no Crow): 35%; Flight Mode 1 (Gear Down, Flaps at Take Off, no Crow) 60%; Flight Mode 2 (Gear Up Flaps at landing position with Crow) 60%. The Flight Modes are controlled by the flap switch.

Dustin made these sensitivity adjustments while I flew the airplane, and they worked out absolutely perfect.
Overall, I am very satisfied with my Demon, and look forward to many more great flights!!
Harley,

What switch are you using on your 12X to control the gyro function and how was Dustin able to adjust the sensitivity during flight?

Thanks,

Craig
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Old 09-12-2014, 05:18 AM
  #58
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Quote:
Originally Posted by mmontella View Post
The jet that I plan to put my Cortex into is curretnly set up with a SmartFly EQ-10. I have two elevator servos going into one input on the SmartFly then into a single input on the receiver. The ailerons are set up the same way. The smartfly acts as a matchbox in this configuration. My question is, can I use the Smartfly with the Cortex at all, and if so, would I have to seperat the elevator and aileron servos on their own input to the smartfly then into the Cortex?

Mark
Mark,

I know Bob already gave you a pretty complete answer but as I recall, since SmartFly provides a very low current regulated separate power supply for the receiver, they state that you should not connect anything to the receiver except the SmartFly ports. Since the Cortex WILL draw power from the receiver, the regulated power supply that SmartFly provides may not be adequate, even though it wouldn't be powering servos directly. I know that people connected a single servo directly to the receiver in a SmartFly unit have had issues because of this. At the very least I would contact the owner of SmartFly and ask him about this as I've heard he is very helpful. I'm correct about this and I'm by no means certain that I am, that would only leave you the option of separating all of the channels and connecting the Cortex between the SmarFly and the servos. To be honest, I don't see any real value to the SmartFly unit in this configuration and if it were me, I would simply tear the SmartFly out of the plane. If you separate each elevator, aileron and the rudder that leaves only the flaps and the throttle going through the smart fly. If you're setting this up on your JR12X, a 12 channel power-rsafe receiver would probably be a far superior replacement for the SmartFly unit if you are adding a Cortex.
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Old 09-12-2014, 08:11 AM
  #59
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Hi Wayne, its Bob Michaud. We were tent neighbors in Maine last weekend. I don't know if you noticed butmy Elan had a Cortex in it all plugged in to an Orbit power jack. Isn't that similar to a Smart Fly in function?
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Old 09-12-2014, 10:18 AM
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Quote:
Originally Posted by Meesh View Post
Hi Wayne, its Bob Michaud. We were tent neighbors in Maine last weekend. I don't know if you noticed butmy Elan had a Cortex in it all plugged in to an Orbit power jack. Isn't that similar to a Smart Fly in function?
Hi Bob, It's good to hear from you but unfortunately I didn't notice your Elan had a Cortex in it or how it was setup. While the Orbit power jack provides some similar functionality to the SmartFly unit, it appears to be more compact and mainly focuses on providing dual receiver batteries and good power distribution to the servos. The SmartFly unit also provides the ability to "fan out" multiple servos from a single receiver channel, such as driving 2, Aileron servos from a single receiver channel. Some of the Smart Fly units also provide servo reversing and end point adjustment functions as well.
Since the Orbit power jack seems to plug right on to the receivers servo ports, you would of course need to connect the Cortex externally and that makes perfect sense.

Thinking further about my previous post, much of what I said about connecting the Cortex externally seeming to bypass the SmartFly's functionality came from the assumption that the Ailerons, Elevators and Rudders would need to each be placed on a separate receiver channel, instead of using the SmartFly to drive the multiple servos. I now, don't see any reason why that would be needed. As long as the SmartFly is configured to correctly drive each servo and provide the desired servo travel it seems the best way to connect the Cortex would be to simply connect the Cortex between the SmartFly unit and the servos without making any other changes.
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Old 09-12-2014, 10:19 AM
  #61
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Just curious can you install the gyro on a plane with dual rudders (F15) that are Yd into the receiver? Can just just plug the rudder y harness into the appropriate gyro port? Will that work?
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Old 09-12-2014, 10:35 AM
  #62
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Quote:
Originally Posted by Dieselman1220 View Post
Just curious can you install the gyro on a plane with dual rudders (F15) that are Yd into the receiver? Can just just plug the rudder y harness into the appropriate gyro port? Will that work?
Actually, I've been told that you can connect up any five servos and that the Cortex will figure out the functions during setup. Say you had a jet that used only Ailevators (no Ailerons), you could connect the 2 Ailevator servos and if you had dual rudder servos, you could connect each of them to the Cortex separately and still have a channel to spare. As long as your transmitter was setup to provide the correct inputs to each channel during setup, the Cortex is supposed to be able to figure out how to stabilize a plane that uses these types of functions.

Of course if you had separate Ailerons, Elevators and Dual Rudders, you would need to tie the dual rudders together somehow. Personally, I would be inclined to use a matchbox rather than a Y harness to allow me to fine tune each rudder servos travel, centering, etc.
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Old 09-12-2014, 10:42 AM
  #63
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Quote:
Originally Posted by wfield0455 View Post
Thinking further about my previous post, much of what I said about connecting the Cortex externally seeming to bypass the SmartFly's functionality came from the assumption that the Ailerons, Elevators and Rudders would need to each be placed on a separate receiver channel, instead of using the SmartFly to drive the multiple servos. I now, don't see any reason why that would be needed. As long as the SmartFly is configured to correctly drive each servo and provide the desired servo travel it seems the best way to connect the Cortex would be to simply connect the Cortex between the SmartFly unit and the servos without making any other changes.
Wayne,

To confirm your last paragraph, I'm using a SmartFly EQ-10 with the Cortex and all is working fine. The Cortex is connected between the SmartFly and the surfaces as if the SmartFly was the RX. No changes to the SmartFly configuration were required, a simple plug and play of the Cortex.
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Old 09-12-2014, 11:20 AM
  #64
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Joseph,

I have my two rudders and the nose wheel on the Matchbox and it works great.
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Old 09-12-2014, 11:49 AM
  #65
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Sure!
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Old 09-12-2014, 11:49 AM
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Quote:
Originally Posted by Dieselman1220 View Post
Just curious can you install the gyro on a plane with dual rudders (F15) that are Yd into the receiver? Can just just plug the rudder y harness into the appropriate gyro port? Will that work?

Sure!
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Old 09-12-2014, 12:18 PM
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Quote:
Originally Posted by f106jax View Post
Wayne,

To confirm your last paragraph, I'm using a SmartFly EQ-10 with the Cortex and all is working fine. The Cortex is connected between the SmartFly and the surfaces as if the SmartFly was the RX. No changes to the SmartFly configuration were required, a simple plug and play of the Cortex.
Mike,

Thanks for confirming that, I tend to over think things at times...
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Old 09-12-2014, 04:43 PM
  #68
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I have a recently installed Cortex in an electric jet. Very happy with the way it tamed things down inflight. I was disappointed that landing in a crosswind, the jet crabs as much as it did without a gyro.

My main motivation in going with a gyro in the first place was the idea that it would correct for the adverse yaw in a crosswind landing. Was this just wishful thinking on my part?
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Old 09-12-2014, 05:16 PM
  #69
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Quote:
Originally Posted by Steve Collins View Post
I have a recently installed Cortex in an electric jet. Very happy with the way it tamed things down inflight. I was disappointed that landing in a crosswind, the jet crabs as much as it did without a gyro.

My main motivation in going with a gyro in the first place was the idea that it would correct for the adverse yaw in a crosswind landing. Was this just wishful thinking on my part?
Were you in heading hold mode?
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Old 09-12-2014, 07:45 PM
  #70
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No. I believe heading hold mode is used only in a helicopter application.
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Old 09-13-2014, 01:21 AM
  #71
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Steve,

The CORTEX (or any gyro) won't correct a crab when in rate mode. Rate mode only dampens disturbances so providing the model is crabbing 'smoothly' there are no disturbances to damp down. It doesn't affect drift (i.e. crab) just roll, pitch and yaw.

You may be able to get the response you want in hold mode but, as you say, most people don't use hold mode other than for hovering when 3D flying.
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Old 09-13-2014, 04:05 AM
  #72
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Quote:
Originally Posted by Steve Collins View Post
I have a recently installed Cortex in an electric jet. Very happy with the way it tamed things down inflight. I was disappointed that landing in a crosswind, the jet crabs as much as it did without a gyro.

My main motivation in going with a gyro in the first place was the idea that it would correct for the adverse yaw in a crosswind landing. Was this just wishful thinking on my part?
You use a couple of different terms that make it unclear exactly what the problem you're having is. You say it "crabs as much as it did without a gyro" and also that you wanted it to correct for adverse yaw.

The amount of yaw required to keep the plane traveling a straight path over the ground (down the runway) will never vary because of the use of a gyro. The tendency of the plane to turn the nose into the wind, WILL be greatly improved by a gyro. If you are noticing that the plane still wants to turn into the wind with the gyro enabled, I suspect that your gain is too low or you don't have enough rudder travel.
While the Cortex won't eliminate the tendency to yaw into the wind it WILL, once setup correctly, dramatically slow it down to the point where only a small correction here and there is needed to keep the plane pointing down the runway. You still need to point the nose in the correct direction to keep the plane traveling the correct path over the ground and then straighten it out just before touchdown.
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Old 09-13-2014, 04:41 AM
  #73
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In rate mode, the gyro will only dampen down the yaw rate. It won't return the model to the original heading which is what is needed to stop the crab. In rate mode you will have to point the model where you want it to go.
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Old 09-13-2014, 09:18 AM
  #74
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If the model does not crab into the wind it move laterally across the ground moving away from the runway centerline.
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Old 09-13-2014, 09:29 AM
  #75
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Quote:
Originally Posted by Steve Collins View Post
No. I believe heading hold mode is used only in a helicopter application.
You have the option set any the axis to rate or HH mode using the pc, however even in holding hold if landing in a crosswind the model will have to crab to main it path accross the ground.

I have bank two setup up with just the aileron in HH mode, its rather interesting flying the model this way.
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