FBL Gyro Final B.D. Axon Tuning??

[Heliman450]

Hi all, I think I can declare my winter project completed. Here's a video of my 'final' Bavarian Demon Axon setup drama.

Thanks to all the viewers of the build threads My New T-Rex 700X Build and my previous gyro thread Tuning B.D. Axon Gyro on my T-Rex 700X.

Special thanks to Steve for his direct help and advice along the way.

I'll cover any follow-up here as the other threads have become very long as the time has passed by.

 

[D.O.G.]

Nice going Heliman 450. Your getting their. Seems to me that you do alot better and you seem more stable to fly without the trainer. Good job and glad to see you are getting some airtime in. Keep up the good work! and videos coming.

 

[Heliman450]

Hi D.O.G., thanks for the encouraging words. The training/test gear was there for insurance having suffered damage during the first test hovers. I made it up and used it in this case to be able to show the difference between the heli's stability with the different settings. I hardly touched the sticks, so the improvement during the video is solely down to arriving at a satisfactory value for Gain (60%) and Sensitivity (48%), which are my current Blue Bank settings. I'll reset the others to be more in line with this and probably fine tune in due course.

Just waiting for some better weather and I'll be investing in another four batteries to give me more flying time before having to charge.

 

[Smoggie]

Looks like huge improvement.. Out of curiosity.. what are the default settings?

I've never set up an Axon but on the decent quality FBL I've set up (including a BD 3SX) the default settings were pretty darn close. The only FBL that didnt work very well at default settings that i've had was the tricky old Align 3GX.

 

[Heliman450]

Hi Steve,

I'll need to check to be 100% sure, but as I recall there aren't any default settings for the gyro Gain and Sensitivity. This is where they're very vague and talk about "a value less than you expect". In previous threads, I mentioned about the very odd, low values to stop the heli from wagging itself to pieces. I slowly built up the values after having changed the setup many times. Finally, I played around with servo travel and the trim until I got what I saw as the least variation on the 'Aileron 2' (right-hand) servo. It will centre out perfectly but won't maintain it at the top/bottom limits. The attached screenshot shows the final position for the trim. They are all very close but for 'servo 2' the direction is reversed, so is showing a positive value rather than a negative one like the other two.

At the moment, my preference goes with the Spirit Pro for the best performance. The Axon only gives the four basic options of flight style against the Spirit Pro's step-wise selection. I dropped it from a value of 4 to 3 and saw an immediate improvement in stability although they describe it quite negatively in their text as being "more robotic". I found it much closer to the Phoenix simulator response with the 'Active Flybar' selected.

I'll look into my screenshots tomorrow to check for the 'default' gyro settings and get back.

Bye for now.

 

[Heliman450]

OOPS! I forgot the attachment.....

 

[Smoggie]

Only thing that jumps out at me on the screenshot is that the tail gyro input appears to be a negative value resulting in rate mode. 99% of people prefer heading hold as it eliminates drift of the tail.

 

[Heliman450]

Hi Steve, I intentionally set a 'Rate' value in the video as the yellow bank setting with the same 'HH' values in the gyro as the red bank (red bank is only in the unit with the Tx. settings having zero Gain and Sensitivity). The value I expected to work best as first trial was the blue bank setting of 58% Gain and 46% Sensitivity.

I wanted to see for myself (and capture it on video) exactly what it looks like to have a very low setting and understand what the written descriptions I've seen mean in practice. I think it worked perfectly as a demonstration of the differences. The 'Rate' setting meant that it was almost impossible to lift off without great risk to the heli (hence my test gear). It was possible to lift off with the 'HH' equivalent but it just wouldn't stabilise in a hover without me constantly chasing it. The final blue bank setting worked extremely well, I almost didn't need to do anything to keep it on the mark. The final day's test without the gear fitted was a dream and I'm sure there's still enough fine tuning to do by taking it to the point of wag and backing off but that's for another day.

What I noticed about the LED indications for yellow/red/blue banks was that there needs to be a significant difference between the settings to show the different colour (about 3% minimum).

I'll dig out those default settings a bit later on.

 

[Heliman450]

Hi again Steve, attached are two pdf's I featured in threads a while back. One shows my interpretation of the guidance as of 29.12.16 (12.29.16 for our U.S. readers ). As I thought, the defaults are all the same despite the chosen flight style and they're also low from what I have arrived at. At 60% Gain, I still feel I could go up but for what I'm doing right now the tail is more than under control.

I'm not sure yet whether I'd change the wording after my most recent experience. However, after a quick glance it seemed good to go.

 

[Heliman450]

Hi Steve, I just noticed that I put this thread in the wrong FB Forum. It should be in FBL, not FB. Any chance you can do the honours and swap it over for me. Sorry, I must have been trying to publish it a bit too quick

 

[Smoggie]

Done!

 

[Heliman450]

Cheers!