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Old May 03, 2014, 12:59 PM
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Canada, ON, Mississauga
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Step 4:
Mix GyroSpeed to GyroSens

I initially used two free mixes assigned to swtiches. The flight modes allowed me to use one mix. Zero master in all my old modes and the amount of speed mixed in for my GyroNormal and GyroHold modes.

Create a free mix . Mix GyroSpeed to GyroSens. Change from global to flight mode specific. Then in the gyro modes change the master value to reduce gain. This means subtracting in Hold and adding in Normal

Mix for all non gyro flight modes.

Name: Speed to Gain Free Mix.bmp
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Mix +20% of speed signal to gain in Normal mode

Name: Mix for GyroNormal.bmp
Views: 19
Size: 225.1 KB
Description:

Mix -40% of speed signal to gain in Hold Mode.

Name: Mix for GyroHold.bmp
Views: 21
Size: 225.1 KB
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I didn't change any mix sub settings. Just flight mode and master gain.
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Last edited by cravenjw; May 03, 2014 at 06:05 PM.
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Old May 03, 2014, 01:18 PM
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Canada, ON, Mississauga
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So if we still have original suggested Cortex -20/+40 gains, this new speed feedback will give following gains that look like this:

...................................Speed (m/s)
Mode.................0............25............50
Normal.......... -20%......-10%.........0%
Hold................40%........20%..........0%
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Last edited by cravenjw; May 03, 2014 at 06:42 PM.
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Old May 03, 2014, 01:26 PM
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Crank Up The Gain!

Lowering the gains we original based on high speed oscillations, means we can now raise our global Cortex gains so at the stable low speeds we get strong effect!

I the first couple of flights i have gone from the stock gains (above) to -30%/+50% with no ill effects.

Name: Normal Mode gain with speed feedback.bmp
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Name: Hold mode gain with speed feedback.bmp
Views: 19
Size: 225.1 KB
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I still have my +-10% trim knobs, so i can really go to -40%/+60% with them.

I hope that get people thinking. I sure other guys will do things different. Jeti is pretty flexible in that way.

I will be posting some ideas regarding Telem Control mapping. Its not as flexible as i should be. But for now, its a lot fun!!!
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Old May 03, 2014, 06:25 PM
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Some Logs from a flight.

MGPS Speed telem values
Name: MGPS Speed Part1.bmp
Views: 14
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Name: MGPS Speed Part2.bmp
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MX1 Speed Telem Control
Name: MX1 Speed Control Part1.bmp
Views: 17
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Name: MX1 Speed Control Part2.bmp
Views: 15
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This was a earlier flight. I was using a 0-25m/s (conservative mapping), rather than the full 0-50m/s.

The result is the fast flight peaks are saturated (flat).

There is also a bug here. This is a graph of the MX not the function. The range is -100,+100
The graph scale is not incorrect!

If i could log/graph the GyroSpeed function (cant log/graph function), scale would be correct, but the data would of from 0-100, not 50-100 like in this slightly misleading log graph.
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Old May 03, 2014, 06:39 PM
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Canada, ON, Mississauga
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To HUSH or not to HUSH!

I bought the HUSH kit. Basically a foam boot than fits over the Cortex. It was a required item for gas and turbine installations before recent firmware changes. Apparently, digital filtering in the Cortex software has made it not necessary.

I read a post somewhere, a guy upgraded to this newer firmware and removed the HUSH boot. He said he didn't like it. Don't do it!
I decided to see if it made a difference. This is just my opinion, but i think it does make things better after my limited testing.

Cons, its a real pain in the ass to get wiring thru and installed with it.

My solution, was to slit in open on one-side. The opposite side from the connectors. I do all the setup installation. I install a short 3" extension in the bind/data port for future programming. Then in pull open the Hush boot (now split) and easily install it around the cable and cortex body. Then a wrap of electrical tape holds in closed like it was never split!
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Old May 04, 2014, 10:51 AM
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It will be interesting to know if you feel a difference between the way the Cortex acts with the GPS compare to the MSpeed airspeed sensor once you switch
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Old May 04, 2014, 11:51 AM
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Quote:
Originally Posted by Puttputtmaru View Post
It will be interesting to know if you feel a difference between the way the Cortex acts with the GPS compare to the MSpeed airspeed sensor once you switch
Should have MSpeed on Monday. Might be able to get it installed before next weekend. I flew today, in 40kph solid winds, with +50kph gusts. Was quite exciting even with cortex. Not sure gps speed feedback helps as I was stationary much for the time, and had full gain, with a real airspeed of 40-50kph! This is where the gps feedback gets doggy!

However, I would have never considered flying in those conditions before the cortex. Had a big audience, nobody else flew! Landing we're still exciting but manageable.
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Old Jun 09, 2014, 05:07 PM
Michael
United States, ME, Wells
Joined May 2008
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Cortex and Eagle Tree Guardian Installed in a Visionaire

For grins, I decided to investigate a Cortex and a Guardian on the same airframe; in this case my foamy Visionaire. A Jeti 7-channel Rx drives the Cortex that, in turn, drives the Guardian, and the three servo connections (used as shipped Y-connected ailerons, elevator, and rudder) are connected to the Guardian.

I setup a couple of mixes, logical switches, and flight modes to ensure that either Cortex or Guardian were enabled, but not both. I also used a momentary stick-end switch to force Guardian 2D flight mode, 100% DR, no EXPO regardless of Cortex or Guardian mode. A knob controls Guardian master gain and the two sliders control the Cortex RATE and HOLD gains. I did have to use the PC to configure the Cortex for inverted mounting, but that was the only change from "out-of-the-box" for both devices.

Bottom line, all works great, but still getting used to Cortex HOLD mode and the transition to forward flight. The adjustable gains also work great, not GPS driven, but I did follow the suggestions in the posts; thanks, huge help. All three gains were cranked up 'till oscillations, then backed off; close to the ranges posted in various forums.

I am trying to get one of the club members to capture some video to showcase the various modes, but I suspect nothing new as it all behaved as expected.

If anyone is interested in the logical control of the two flight stabilization devices, let me know and I can post some screen shots. I figure that this was an oddball experiment and not many folks would be interested, but I thoroughly enjoyed the flexibility of my Jeti DC-16 in getting this to work.

Michael
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Old Jun 09, 2014, 05:45 PM
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Quote:
Originally Posted by Snowflake6515 View Post
For grins, I decided to investigate a Cortex and a Guardian on the same airframe; in this case my foamy Visionaire. A Jeti 7-channel Rx drives the Cortex that, in turn, drives the Guardian, and the three servo connections (used as shipped Y-connected ailerons, elevator, and rudder) are connected to the Guardian.

I setup a couple of mixes, logical switches, and flight modes to ensure that either Cortex or Guardian were enabled, but not both. I also used a momentary stick-end switch to force Guardian 2D flight mode, 100% DR, no EXPO regardless of Cortex or Guardian mode. A knob controls Guardian master gain and the two sliders control the Cortex RATE and HOLD gains. I did have to use the PC to configure the Cortex for inverted mounting, but that was the only change from "out-of-the-box" for both devices.

Bottom line, all works great, but still getting used to Cortex HOLD mode and the transition to forward flight. The adjustable gains also work great, not GPS driven, but I did follow the suggestions in the posts; thanks, huge help. All three gains were cranked up 'till oscillations, then backed off; close to the ranges posted in various forums.

I am trying to get one of the club members to capture some video to showcase the various modes, but I suspect nothing new as it all behaved as expected.

If anyone is interested in the logical control of the two flight stabilization devices, let me know and I can post some screen shots. I figure that this was an oddball experiment and not many folks would be interested, but I thoroughly enjoyed the flexibility of my Jeti DC-16 in getting this to work.

Michael
Sounds neat! I am still learning to "unwind" the hold! It definitely takes some practice to change orientation quickly.
I have been experimenting with a momentary switch, that will change hold to normal mode. I been pulling this just before and during abrupt changes. It seems to zero the integrated "hold" values. The transitions are smoother. Then I let go (back to hold) when close to the new orientation.
As I fly it more I am rarely using the hold mode.
I have two planes setup with the GPS speed feedback. I have a third cortex ready to go on a new airframe, but I will try the mspeed sensor with this setup.

One issue I am having is a rudder oscillation. Played with gain a lot, but i was having to go way to low.

Turned out to be a mechanical feedback. The cortex was mounted on the rudder servo tray, just a head of the servo. My pull pull cable had stretched and was quite sloppy! The cortex got the rudder servo into a stable cycle even a low gains. Playing with the tension on the pull pull eliminated much of this mechanical coupling. But as time permits, I will move the cortex to a new tray that is not coupled so closely to the rudder servo.

So if you get a oscillation, don't always blame to cortex. Sometimes it's worth looking at the mechanical setup also.
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Old Jul 05, 2014, 10:04 AM
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Joined Feb 2014
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craven, this is very very helpful.. thanks to you, i just set up my 78" extra / da 35 / Jeti R11, with the cortex. i tested it with all 3 modes, and surfaces move accordingly. only one issue, when i use the BD cortex PC program, it states under bank 1 and bank 2 that "rudder" is not active. what does this signify?
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Old Jul 05, 2014, 10:57 PM
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flew her twice today, and i am impressed. Much better than my first experience with this on a different airplane. this time, it worked!!! i used a gelatinous type double sided tape on a small hardwood square that i epoxied to the balsa over the tunnel. on "normal mode" definite improved flight, take off, landing. knife edge was smooth, aileron rolls were smooth. on hold mode, quite impressed, was able to hover it, and then i raised my transmitter with hands off sticks so that all my friends at the club could see the cortex at work!!!
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Old Jul 07, 2014, 01:44 PM
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Quote:
Originally Posted by orthobird View Post
flew her twice today, and i am impressed. Much better than my first experience with this on a different airplane. this time, it worked!!! i used a gelatinous type double sided tape on a small hardwood square that i epoxied to the balsa over the tunnel. on "normal mode" definite improved flight, take off, landing. knife edge was smooth, aileron rolls were smooth. on hold mode, quite impressed, was able to hover it, and then i raised my transmitter with hands off sticks so that all my friends at the club could see the cortex at work!!!
Glad things are working good for you!

I have another mGPS enabled setup running! Finding gain tuning really different on all three planes. All 3d but, overall gains and which surface needs individual tweaking is quite different with each one.
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Old Jul 08, 2014, 03:15 PM
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Another thing that is making a huge different in gains is the servo torque/speed. I have two very similar planes (size, weight, area, loading, surface sizes), but one with 7 x 400+ oz.in servos and the other is 5 x mks777 servos. The mks under load are performing much better (faster) and i am using much lower gains for the same cortex stabilization!
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Old Sep 08, 2014, 05:11 AM
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Germany, NRW, Gangelt
Joined Jan 2011
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With the new Jeti firmware update for the receivers, you can combine mixed servo and PPM outputs.
Did anyone install this setup (AIL,RUD,ELE)out of the Cortex through PPM, and the rest of the servos out of the receiver?
This would simplify the cabling in your model.

I hope there is a step by step manual out there.
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Old Sep 08, 2014, 07:06 AM
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Quote:
Originally Posted by easy jets View Post
With the new Jeti firmware update for the receivers, you can combine mixed servo and PPM outputs.
Did anyone install this setup (AIL,RUD,ELE)out of the Cortex through PPM, and the rest of the servos out of the receiver?
This would simplify the cabling in your model.

I hope there is a step by step manual out there.
I have tried it. I used the 150cm cable loom. Stays pretty neat. Not that my dumb thumbs can tell, but why give up fast update rates of a servo wired scheme for slower ppm rates?
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