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Jun 17, 2016, 09:23 AM
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Graupner receivers with 3xG setup and fine tuning help


Hello my father has bought a new MZ-24 with GR-18 3xG+3A+Vario RX.

We are testing it on a small 3D plane 1.2m wingspan. I have question about the page relative to Gyro fine tuning on the Radio.

As i understand the values from 0 to 10 on both Aileron Elevator and Rudder are the P (of the PID) value for each axe.

The Coeff. value is a sort of a MASTER P gain that can "SCALE" ALL the value above in the same time with a major priority so for example if i have all the previous values at 5 if the Coeff. is a 0% all the P values above will be 0 (so is like to have gyro OFF) if the Coeff. is at 100% the P values will be to 5 if Coeff. is at 200% the above P values will be 10. Is it right?

The Coeff. D value instead is the D factor of the PID and it's value is the same for all axis. I can't find where to change the D value for each axes independently and this part is confusing in the manual.

Well said this in initial flights it is better to left coeff and coeff.D to OFF or 100% (it is the same) and use separate channels to control each axes P values with a knob or a slider independently.
After the right P values are found where the plane doesn't oscillate on the axes on a middle speed flight it is time to FIX the found values and activate on separate channels the COEFF and COEFF. D parameters so it will be possible to fine tune the system for slow flying or if the axes has unnatural behaviour or if it has a bounce on manoeuvre stop. The goal will be to achieve a natural and crisp control.

This is what i understand let me know if it is the right way to obtain the right performance.

Thanks
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Jun 18, 2016, 09:27 AM
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Hello,

i think you are absolutely right.
It's not possible to alter the values of coeff or coefficent d per axis. You can't change the value for each axe.
Jun 20, 2016, 08:01 AM
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Ok i have done some flights. The system work good but leaving Coeff. to 100% that correspond to factor 5 on all axis (those values were fine tuned before) and going to 60% of Coeff. D i still have some bounce on stops specially on aileron axis.

Anyone can describe please what to aspect from the right relationship between Coeff. and Coeff.D and how to know when this point is reached?
Jun 20, 2016, 05:43 PM
You can change the gain as well as each axes throw value value during flight by assigning either a control or multiple offsets for each flight mode.
Jun 28, 2016, 04:52 AM
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Quote:
Originally Posted by Graupner USA
You can change the gain as well as each axes throw value value during flight by assigning either a control or multiple offsets for each flight mode.
That is what i have done.

At first i set on individuals channels and knobs the 3 P Factors values (from 0 to 10) leaving Coeff and Coeff. D to default 100%. When i found the right values with no oscillations on each axes i switched the values found to fixed and used two knobs for regulate Coeff. value and Coeff. D

What i have to understand better is the relationship between Coeff and Coeff.D and what Coeff. D really do and it's limit.


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