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Feb 18, 2017, 12:10 PM
Blue Skies
hifinsword's Avatar
I had an uncommanded surface movement on the elevator surface using a different Rx/Stab, which led to a crash. I was able to confirm the problem was due to the TRAVEL being over 130%. The problem only happened with TRAVEL over 130%, only in HIGH rates, and only with UP ELE.

I've come to believe with these smart Rx/Stabs that you cannot have the TRAVEL above the recommended setting, or 100% to be safe, if none is recommended as in my case.
Don
Last edited by hifinsword; Feb 18, 2017 at 12:16 PM.
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Feb 18, 2017, 12:17 PM
Ian
Quote:
Originally Posted by R. Nordeck
....so I attributed that one to a "brownout" as a wild A. guess....
For anyone interested, here is the telemetry output. As can be seen the flight was very short! I took off and climbed steadily while executing a 180 degree turn. The plane had returned to a point almost directly in front of me at about 150 yds horizontally away from me and then went into a very steep dive.

As this crash was totally unexplained and I have just completed rebuilding the same model it would be good to understand why it crashed! I am quite happy to accept it when a crash is my fault but hate it when I have no explanation. Apologies that this is a posting which in this case is not an AS3X receiver, but as it has great similarities with the posting relating to an AS3X receiver it seems appropriate.
Feb 18, 2017, 12:28 PM
Registered User
R. Nordeck's Avatar
First telemetry graph I have seen; does it show U anything strange?

As an Ol Timer in our club says: " I just ran out of altitude, air speed and ideas; all at the same time". Great one liner and kinda like my favorite cliché: "It All Depends" ......
Feb 18, 2017, 12:35 PM
Ian
Quote:
Originally Posted by R. Nordeck
First telemetry graph I have seen; does it show U anything strange?

As an Ol Timer in our club says: " I just ran out of altitude, air speed and ideas; all at the same time". Great one liner and kinda like my favorite cliché: "It All Depends" ......
Not really, which is the annoying thing. It does show 3 frame losses (but NO holds), short periods where telemetry signal was lost and a rapid loss of altitude at the end - I certainly ran out of altitude, have no ideas as to why but there was plenty of airspeed (until it stopped abruptly!)
Feb 20, 2017, 07:19 AM
Crash Test Pilot
ddoucette's Avatar

Feature request


This bit of advice from Freechip on using remote AS3X gain adjustment is what I consider to be the standard technique to get the AS3X gains set correctly.

Quote:
Originally Posted by freechip
Why not remotely adjust them while flying?
Set gains for one surface to 100% REL and then enable AS3X telemetry on your transmitter and adjust them remotely.
Once in the air adjust until surface oscillates then back down a little. I usually adjust at full throttle.
Then take note of the value and lock it in the receive by changing back from 100% REL to 53% ABS for example.
Then repeat for the other surfaces and voila.
What I do is set aileron on one FM, Elevator on another and Rudder on the 3rd flight mode.
Each set to 100%Rel and during flying I switch flight modes and adjust each control surface taking note of the value the control surface starts to oscillate then back down.
Then once on the ground I lock in the value.
Andy, I'd like to submit a Feature Request to add the option of selecting a slider control or pot on the transmitter to adjust AS3X gains. I find the LTrim and RTrim difficult to find or reach when I'm concentrating on flying at full throttle. This is where some flexibility in choosing what input people can use would be very helpful.

Thanks,
Dave
Feb 20, 2017, 07:38 AM
Registered User
Already done I think. You can use any control to adjust the gains. Ltrim, Rtrim, knob, switch, mix, whatever. Its whatever you send out that channel.
Feb 20, 2017, 08:00 AM
Crash Test Pilot
ddoucette's Avatar
Hi smdub. I'll have to look at it again with my model. I just looked at my Dx9 and this is what I have set:

I'm running Airware 1.11 and on the AS3X Gains screen, under "Input" I am only presented with L Trim and R Trim. If I move a slider or other input to select it instead, nothing changes.
Channel is set to AX3 (matches config from app) and FM Switch is D.

I looked at my channel assignments and they are Ch8 = Aux3 and Aux3=FMode. However, I also noticed Aux4 = FMode.

I'll create a new model to try it again. Perhaps I have something mis-configured.

Thanks
Feb 20, 2017, 08:06 AM
Crash Test Pilot
ddoucette's Avatar
BTW - This is the model I'm flying the AR9350 in. Right now, all gains are at 0%. I hope I can get to adjust the gains on a slider the next time I take her out.

F16 flights 2-19-2017 (5 min 56 sec)
Feb 20, 2017, 09:02 AM
Registered User
I can't remember how I did it but I have used the knob (as have others.) I've done it w/ a DX8 that doesn't have trimmers. Don't have the radio in front of me but IIRC you create a mix to output the knob (or sliders or whatever) onto Aux1 (or whatever channel your flight mode is on?). Its the same thing that built in AS3X tx screen now does w/ R/L trim you are just doing it manually. Not sure why they limited the AS3X selection screen to just the trimmers (can't say I ever noticed that.) I'm at work now but if you google or search here on something like 'as3x relative gain pot' I'm sure you'll be able to find the same instructions I found.

Edit: another way to figure it out is to configure it w/ the trimmers like you have, go to your monitor screen and see what channel they are affecting and by how much when you adjust it to min/max, then disable the trimmers and go create your own mix to replicate that.
Last edited by smdub; Feb 20, 2017 at 09:11 AM.
Feb 20, 2017, 09:34 AM
AndyKunz's Avatar
Quote:
Originally Posted by ddoucette
Andy, I'd like to submit a Feature Request to add the option of selecting a slider control or pot on the transmitter to adjust AS3X gains. I find the LTrim and RTrim difficult to find or reach when I'm concentrating on flying at full throttle. This is where some flexibility in choosing what input people can use would be very helpful.
You'll need to make that mix manually.

The reason we WON'T do that is because the gains are adjustable per flight mode, which means we need to remember in each flight mode how you have adjusted it.

We do that by setting the selected trimmer to F-Mode (vs. Common) and making the mix (P-Mix 16) to put it in properly.

Andy
Feb 20, 2017, 09:44 AM
Crash Test Pilot
ddoucette's Avatar
Thanks guys. Got it and I understand what the consequence would be otherwise. Ok, will make a mix.

Cheers,
Dave
Feb 22, 2017, 01:32 PM
All aboard Flight 666
grant22's Avatar
Andy and others:

I have put a programmable AS3X rx in my tedbull Edge 540. Ever since installing this AS3X rx in there I've been having some serious, what feels like, tail heavy issues.

all fyi's: previously had a citrus rx in there and didn't have this issue (but lost signal once so I removed it), the as3x rx in it now I have removed the gain settings before installing.

What could possibly be going on? Should I be sending this rx in for evaluation?
Feb 22, 2017, 01:43 PM
AndyKunz's Avatar
Which receiver?

What does "tail heavy" mean? In an aerobatic plane, you want the CG as close (but still forward of) to the NP as you can. AS3X benefits from this by making it easier to stabilize. You test for tailheaviness by being in a mild inverted dive and taking your hands off the controls - if tail-heavy it will return to level. If correct it will hold its attitude, and if nose-heavy it will dive harder. Properly trimmed it will stay in the dive whether inverted or not.

Or are you saying that it is more responsive? In pitch only, or pitch and roll?

After you changed the receiver, did you verify that the controls had the same max deflection as before? Not everybody follows the standard of 900us to 2100us as the maximum (complete 2048 step = 150% travel) signals.

Andy
Feb 22, 2017, 02:57 PM
All aboard Flight 666
grant22's Avatar
Thx Andy for the response. As of now what I'm experiencing with the plane is it balances fine before flight with a slight forward bias. Rx is an AR636 from another plane.

Upon take off (neutral elevator) it shoots nearly straight up (close to full throttle) and then nearly uncontrollable with oscillation. Luckily, the times it has done this, Ive been quick to input down elev trim to compensate

Then after landing, there's visible down elevator.

It wasn't doing this with the previous rx

What I've done with the 636 prior to these flights: I've tried zeroing the gain settings
What I've done after these tail heavy flights: zeroed them out again, and then reset the rx
Feb 22, 2017, 03:08 PM
AndyKunz's Avatar
It sounds like you have some AS3X active, and perhaps with the wrong direction of movement.

Where did you get the receiver? Is it an open stock one, or pulled from another model?

Andy


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