Originally Posted by
wfield0455
Goose,
Since you are obviously very familiar with the Cortex, could you perhaps shed some light on tuning performance with a PC ? I have a Cortex, which has always worked very well with the basic setup for scale type flying or for precision aerobatics. However, I could never seems to get it so I was happy with it for extreme aerobatics. For example, when I needed to corner the sticks to get the airplane to transition from high speed vertical flight immediately into a flat spin (pop top) I could never get the Cortex to stabilize the plane well without feeling it fight me during these extreme maneuvers. I played quite a bit with the various settings for quite a while without much success but I suspect this was because I was never able to find a clear description of each control and how to adjust it to get the desired results. If you have experience with this I would love to learn more about this type of fine tuning of the Cortex parameters. If you know of a link to a good discussion of this type of thing that would be great too.
Thanks
I don't know of a good explanation, but I will try.. its actually very simple in my approach.. never move anything more than 2 points at a time.. basically in the cortex, you can adjust the relative gains, and the stick priority. The relative gains can be adjusted for odd airplanes, for example a delta like a rafale, we had to lower the aileron and elevator gain by 2 points and up the rudder by two points, then try again.. we ended upping the rudder by 4.. what we looked for here was killing the yaw wiggle, but the gain got so high that it caused waggle in the wings too, so we made changes there.
Now for stick priority, this is more tricky.. first I need to make sure when you go messing with the settings have some way to kill the gyro.. the best way is a free mix... gain to gain with a value of -100 it will mix and null it..no matter what gain..
Stick priority: As you feed in stick, the internal damping of the cortex is reduced with the throw.. Its still working but not as much.. for instance: when you do a hammerhead and put full rudder in, the aileron and elevator damping is still trying to make it hold attitude.. If it isn't responding as aggressively as you like, then you can up the stick priority by 2 points in the axis and see if it has any effect
NOW.. the way I would do this is to copy banks so that its stock and factory on one side in attitude mode, and modified in the other.. this way you can switch back and forth simply by moving making your gain the same -40% vs +40% But this requires copying and modifying side 1 to look like side 0.. I don't use HH mode for an airplane... You can use it to hover, but I think it hovers fine with attitude mode.
So.. in an aerobatic plane, if the rudder seems a little mushy with the gyro, first of all, lower the expo by half the amount you have..but you can also learn it in low rates and use more gain, but then if you decide to play with the software you can up the stick priority 2 points at a time.. trust me when I say don't do more than that at at time.. It will result in an unbalanced feel..
Hope that makes some sense guys..
1. the stock settings work pretty good
2. If its mushy, then lower expo first, if its then mushy reduce master gain
3. If its wobbling a surface, lower the gain and relearn with that surface in low and the others in High (typically I learn Ailerons in low rate)
4. If its damping well and smooth, but doesn't seem aggressive enough and you need more on a single axis and can't get it by learning in high or low rate such as rudder, then you can add GAIN first inside the computer 2 points
5. If its damping well, Ie tracking smoothly and straight, but not aggressive enough when you bang the controls, then you can up a priority by 2 points on that axis.. Be careful with this..
Take a methodical approach and leave yourself an out.. I cannot emphasize that enough... we turned off the gyro several times on the delta wing we were setting up.. we eased up on it slowly.. hope that makes sense