Best Expo/Rate settings for a gremlin noob

[Gryf]

Hi, all.

I just finished my first Gremlin build, and with help from some of you have gotten everything debugged, and it's finally ready for flight testing. With that in mind, what would you recommend for rate and expo settings while I'm getting started? I did come across a good video on settings for the Tiny Whoop, but if any of you Gremlin guys have advice, thanks in advance. I'm looking for maximum stability. By the way, this also goes for PID settings, etc.

Gryf

 

[PsyBorg]

Pids will be different for every quad. There is no cookie cutter spec. For most flight controllers these days stock pids can be fine for general flight until you can learn exactly what they do. Changing things not knowing specially on high kv motors can burn gear up really fast.

As for rates and such that I can help you with. I have been working on my Gremlin in its many forms for near a year now and have a set up that is getting close enough to fly 3s indoors in small areas. Most likely a skilled pilot can do this easily on 2s with the settings I use now.

The rates I have are pretty soft in the center of the sticks. I can make mine move roughly an inch or two per second with these but still do crazy flips and rolls when full stick deflection is used. ( I do NOT advise this indoors at all) I have also worked on the Horizon settings to make them smooth yet still functional where you are not fighting the FC for control. Like where you have to force normal auto level quads to even move then they lurch forward all of the sudden then when you release they slam back into place. I don't bother even messing with Angle mode for this reason.

Use the rates and the Horizon mode settings only from this screenie. The pids will NOT work as I was trying to get it to handle 15+ mph winds and you will most likely overheat the motors. One other thing I suggest is to raise your min throttle higher then the normal procedure where you find the minimum spin level then add a few points. I set mine between 1060 and 1070 as it is hard for the Gremlin to catch itself without doing hard butt bombs as Stefan says with stock props and stock motors. It will also make flying in ground effect more stable and let you clip grass you can fly so low and not porpoise a lot.

 

[Gryf]

Thanks! That will help a lot.

By the way, is it better to set up expo and rates in Betaflight vs. in the transmitter?

Gryf

 

[PsyBorg]

Rates are not done like airplanes at all in the radio its all in the software as rate and super rates. For quads you set up basic limits and switches in the radio and thats it. The rest is all done in the software for the FC. If you look at the curves those settings produced Expo really is not needed the way they were done. If it does need expo you just alter super rate to fit the feel and then use rates to bring back the over all rotation desired.

 

[Gryf]

Excellent, PsyBorg - thanks for the info.

On a related note, Josh Bardwell posted a vid recently showing how to adjust the trims on a BeeBrain Whoop using a Taranis radio. Would you happen to know the procedure for the Femto board and a Spektrum?

Thanks,

Gryf

 

[PsyBorg]

Never used trims on a quad before mate. That may be something to do with straight up angle mode which I never touch. I do everything with Horizon mode. There is an in flight accellerometer calibrations that I assume could be mapped to a switch for betaflight. There are also stick commands that can be used before arming as well. They are originally "cleanflight" but work in betaflight as well. I constantly change profiles when out side to test tuning or doing various things.



I have never done anything with a whoop either. My Gremlin is the smallest thing I have or have worked with so far.

 

[Gryf]

Thanks, PsyBorg! Interesting stuff, and I'll keep that chart handy to experiment with. I agree with you about angle mode, but as I'm learning from square one I want as much stability as I can get, at least at first. Hopefully I can build some proficiency and move beyond it later.

As for Whoops, I built one... but it uses the original Inductrix controller, so there's no USB port. And really, it's quite stable as-is. One reason I built my Gremlin was to be able to play with Betaflight and learn more about quad setup.

Cheers,

Gryf