Malcolm H

Goose,

Would appreciate a reply to my query regarding serial data in and out of the Cortex. Full serial bus systems are the way of the future and many people would like to incorporate gyros in them.

Malcolm

gooseF22

Malcom I answered yesterday post #44.. here is the reply:

"No Malcolm, it outputs only PWM Servo Data.. It can read an PPM or PWM input .. It uses software to decode the matrix and assign channels, and then creates PWM drivers for the 5 channels to drive a servo directly.."

The cortex has a passthrough output for throttle and an Aux channel, if Fed 8 chan PPM or serial stream.. but in all cases, it outputs PWM servo output.

AndyAndrews

Can you make an Ikea instruction sheet please?

Malcolm H

Thanks Goose,

Serial in, serial out would be a useful upgrade or maybe a dedicated version.

Sorry I missed your post!

Malcolm

JimBrown

My Feedback: (2)

I've only played with mine on the bench (still waiting for the gd snow to melt) but my understanding of the Guardian heading hold is that it will hold the heading as long as the sticks are centered. Move the aileron and/or elevator stick and the heading hold on all three axis is switched off until the sticks are centered again, at which time it locks on to the new heading.

The rudder is slightly different. When the rudder stick is moved, it only switches off the yaw heading. Roll and pitch heading are still maintained. This makes it very useful for knife edge (or even flat turn.)

The above heading hold stuff is also be combined with rate stabilization that is always active even when heading hold switches on and off due to stick movement.

As mentioned by Bob, always have a switch programmed to disable all gyro functions, just in case.

...jim

gooseF22

I passed that on..

gooseF22

No worries Andy, Jim and I are your pit beotsches.. you are covered.. just show up and fly.. LOL..

gooseF22

Today, we took the hood off the cortex (don't do it!!).. it was a demo model... we stuck it to a 3D foamie.. programmed it, put it in heading hold with 50% gain Green side.. powered it up.. set it in a hover.. let go of it.. and it just sat there hanging on the prop...pretty cool..

it does a good job not over correcting out of the box..


Note to guys that are fine tuning this with the software....when you move the settings in Roll/Pitch/yaw, only move them by 2 at a time max... take your time with it.. IF you change the internal numbers.. Lower the master gain and ease up on it again just like you did in the first flight.. some guys are bumping up the rudder settings by 2-4 points to get a little more punch without touching the aileron/elevator.. again, Take your time.. once you find the magic point, it just settles right down and reacts to your inputs smoothly and when you neutralize the stick, it stops from your inputs now.. a jet guy stopped by today and said it made his flash act like a cruise missile on a laser course..cool..

Note: Don't move the latching/stick priority unless you understand what you are doing.. Those are for fine tuning the reaction to your inputs.. Before messing with these, If its a little soft, spice it up with your lowering transmitter expo..

Gixxy

My Feedback: (18)

Decided to grab a cortex to play with in one of my birds also. Struggling a little bit getting the DX18 setup the way I want. What I'm looking to do is to have my standard 3 flights modes stay the same (Takeoff/half flap, Normal Flight, Landing/full flaps) while not having the gyro active. So basically the aircraft flying as it has multiple times. Then the other flight mode or modes I would like to have it so I can activate the gyro in normal flight so that with the gyro on there is little to no expo. And also have it so in takeoff/landing config aka slower speeds I can increase the gain a tad bit. I just want to be able to switch this bad by off if I don't like what its doing. Ive played with them before but on other aircraft where the owners either didn't have a way to limit the expo when they turned the gyro on or if they took out all there expo and always flew with the gyro turned on. Thats fine and dandy but if for some unforeseen reason the gyro ever came loose I want to be able to turn it off and still have my expo back Basically looking for a DX18 expert that could possibly lend me a hand. I usually just stick with 3 standard flight modes so this is a bit different from my norm. Thanks for the help !

husafreak

My Feedback: (3)

Here is my two cents from a heli guys point of view. Some of the first FBL gyro systems for heli's gave access to all the parameters, it was very difficult to understand them all and the interactions they have with each other. Lots of crashed heli's especially by the guys doing the testing. I followed Curtis Youngblood's daily blogs for a year of his developing his gyro system and tuning the parameters is not for the faint of heart. Fast forward to more modern systems and I have been told by the software developer of Vbar systems that they go to a great deal of trouble to ship a good handling unit. He felt that no heli pilot needs to make a lot of the adjustments we were making. Better to fly it stock and in 99% of cases the pilot will be happy. Why pay to have it developed and then start monkeying around with our limited skills and resources. Most heli gyros did evolve into products that don't need (or can't be) reprogrammed.
I admit that it is the nature of modelers to want to play with everything. But you should expect a device like the Cortex to ship already programmed to a high state of tune. The chances that you will end up with a worse flying gyro after messing with the software are certainly better than making it better.

Max2011

My Feedback: (1)

I use the Cortex on all my EDF types...from 120mm to 90mm.....would not fly without it.
I did have a lil trouble when I first received my unit. I could not get it to work no matter how I tried. Finally I found that the wiring harness was defective. I purchased some aftermarket harness from 3dRC parts and the rest is history. I bought 3 sets of the wiring harness so I can switch planes easily. I never turn the Cortex off on my planes....leave it in the Normal position. Take-off and landing even in cross-winds is a non-event. On landings I just line my plane with the runway and work the throttle to grease most landings. So much more fun flying now.

I found the easy way(and safe way) to mount the Cortex is to glue the unit to a slightly larger than the Cortex piece of ply.....then use two servo screws to attach the ply to the plane. I would not trust the double-sided tape or the Velcro....just saying.

gooseF22

yup, but use the acoustic tape.. its selected for our applications.. just mount to a smooth surface with good adhesion.. very important.. paint the wood, or something to smooth it, CA it, or something like that... This pic, the cortex is mounted to a CA surface

VF84sluggo

My Feedback: (55)

I've wondered if some of the loss of control "due to having a gyro" - as some claim as a reason they would never use one - is from the gyro coming loose in flight. I've thought about a hard mount like pictured above to eliminate this concern. Any worries about vibration with a hard mount? I realize jets have minimal vibes, but still...

gooseF22

good question sluggo..

The software 1.3 has been written to compensate for the acoustic vibration that a jet and a gasser produces.. when you mount it, you use the thin tape for a jet, and a thick tape for a gasser... this allows for a tiny bit of damping.. so in the above photo, I applied CA to the little board, for a good sticking surface, cleaned with alcohol, and then mounted it with the thin tape..

there are probably 50+ or more of these flying in jets now, so far with no issues that Im aware of..

That said, I have a safety switch on my transmitter that I can kill the gain if it were to ever start acting up.. If you feed it 1500 uSec, or mid position, it sees that as Zero gain, and it de-activates totally.. I saw the effects of movement during testing on a velcro mount, so don't be tempted to use it. I then used a very thick tape in the same plane, and it was better.. then the thin tape, and it was more locked in with less oscillations..

just make sure anyone that mounts this, puts it on a surface with good sticking power and that is clean and smooth to mount the tape to.. and to clean it well.. and never reuse the tape.

gooseF22

what you need to do is put the gain on a knob and introduce it slowly in each flight mode, and then zero it out as needed.. thats the way we did Andy's jet with the DX18.. Then later it becomes the mix for turning it off..

mort78

My Feedback: (1)

I also use the Cortex and I absolutely love this gyro, now that its dialed in. It was very good out of the box though.

I used this gyro initially in my 55cc Yak. It's the first time I have ever used a gyro, so I wanted to get the feel for it before I placed it into a more expensive model.
Initially I found that the vibrations from the engine were making the poor gyro work so hard at low power settings (high vibes), even with quite low gain settings. I finally got the elevator and rudder to stop 'fluttering' at low power. I wasn't using the PC software so I knew that all axis were now set at the same gain. I also knew that Ailerons were able to stand a higher gain, with any oscillations. I contacted Bavarian Demon and below is the reply I got. After doing what they mentioned, I have increased the gain a bit and this baby is just so good. I fly using the Jeti DS16, and once the new software comes in where you can use sensors with flight modes etc, this Gyro will be brilliant in all speed ranges. Can't wait. The reply below is for my DLE55cc engine. As you all know, these thing vibrate like mad, so in a Jet I very much doubt you need to do this.

Dear Morten,

you should try to mount a metal plate tot he unit to increase it’s weight and make it less sensitive to vibs.
Here is what you do: use a steel plate of about 3mm thickness and the bottom size of the unit. This should be 2-3 times the weight of the unit itself which is 18 gramm.
Then mount the plate rigidly tot he unit, e.g. by using the thin pad or even something harder. Then use the soft tape to mount the combo tot he airplane.

Btw: note that you can set different gains for each axis by using the PC software. So if aileron needs/can handle higher gains, go for it.

Regards,
Joachim

VF84sluggo

My Feedback: (55)

Maybe I'm misunderstanding, but I thought the point of using a board and servo screws was to avoid using the double-sided sticky foam pad.

Is the point of using the board/screws simply to make the gyro removable, while still mounting the gyro to the board with the vibe-absorbing adhesive pad, thin or thick as the case may be?

Bob_B

My Feedback: (11)

The gyro should be mounted with the thin foam tape.

gooseF22

Yes... Sorry, didn't make that clear..

VF84sluggo

My Feedback: (55)

Got it...thanks!

gooseF22

Just to follow up on the comments above, I did ask our leadership about rigid mounting of the sensor in a jet..

from years of experience with Helicopters, the answer back was.. use the Tape, and to Never mount it directly with any glue..

Bavarian Demon has been mounting their helicopter gyros with this tape or 3M VHB for years with no issues.. Just make sure the site is prepped properly with Epoxy or CA, or use a small plate thats a good hard surface bonded to the wood, then apply the tape to that..

the only exception is when in extreme vibration environment as described above, mount the cortex to a steel plate, (doubling its mass) but then mount that assembly with the foam tape..

Fly with Confidence!!..this thing rocks...

husafreak

My Feedback: (3)

A good quick technique is to spread a layer of gap filling CA on the ply with a card and let it dry. The tape will stick like crazy to that shiny hard finish. Going back to helis again (because that is where a lot of development occured) people have used every type of foam and vibration damping materials/setups imaginable over the years to get their helis to sit still. But the modern 3 axis gyros are so good now, usually thin hard foam tape works best, even the grey and clear 3M tapes (with the red peel off backing) sold in hardware stores work great once you use up the supplied tape. IMHO you are better off with less damping than more, start there and only add thicker foams if you have problems. Also I usually just wrap a velcro strap around the gyro as backup protection from a loose gyro. But those 3M tapes stick like glue.

Max2011

My Feedback: (1)

I am one who does not use tape....I mount like I stated above.........no problems and I used the unit on large and small scale prop and EDF planes. Whatever you do be sure the Cortex is secured so it won't move.

luckyflyer

I have my trims ungrouped on my Futaba 12z so that I can have a different elevator trim for landing with the flaps deployed. Will this cause problems with the Cortex?

gooseF22

we all do that.. no..problem.. all it does is dampen the movements.. if you give it a new "radio input", it sees the inputs and passed it thru to the outputs.. when it works, its acting on the gyro inputs not the physical inputs..

so just set the airplane up as if it isn't there, and then find the gain setting that works for you.. it will turn off a lot of the little movements and it will go where its pointed..