SRx (Access) question regarding end points

[Scottand1000]

Actually, I have 2 questions, both related to the stabilized Rx's. I think the 1st question is easy to answer, the 2nd maybe not. Here goes... (OpenTX-X9D-2019 2.3.15, Archer-X_2.1.10)

1) When an OpenTX model file that controls a FrSky stabilized Rx is saved to the PC, are the various stabilization parameters backed up also? Or, are they only stored in the Rx? Maybe the better question to ask: is there a way to back up the stabilization parameters (i.e. surface direction, gains, etc.) ???

2) I've been using the FrSky stabilized Rx's for 3-4 years now. Both the ACCST version (SxR) and the Access version (SRx). I think they are great. I have them in a half dozen planes. I thought I knew all about them, how to set them up, etc. Never really had any trouble with them. But I ran into something today which tells me I don't understand some things about how they handle end points.

I have a new plane set up with a SR8. Prob 30 flights on it so far. As part of the tweaking process to try to make it groove a bit better, I fiddled with the end point settings on one of the ailerons last night. When I got to the field this morning, I did a cursory check of the control surfaces before flying, just to double check before going up. Long story short, when I toggled between low, med, and high rates with the aileron stick fully deflected, first in one direction, then the other, I found I had lost the additional movement between med and high on just the RH aileron, and in just the upward deflection direction. Weird. I suspected the Rx had lost end point calibration.

This afternoon, I tried to debug. I found that I needed to initiate a self check to get full deflection back, even after the tiniest of an end point change on my model setup. An end point change of say 5% caused the Rx to lose the full range of the travel on that surface. And it lost a significant amount of travel, way more than the tiny end point tweak was in the first place (in this case, 5%). Further, I found if I wanted to increase the travel on an aileron in one direction, I can't seem to do it real time; the aileron doesn't move even though I have the TX and Rx on, and I'm increasing the end point amount in the OUTPUTS screen. I found the only way to do this is to guess how far I wanted to increase the travel (say 5%), then run a self check, then go back and see just how much further the aileron actually moves. If 5% wasn't enough, repeat the process and increase it some more... It's like a trial and error process.

I don't remember having troubles like this on past model setups using the FSky stabilized Rx's. Maybe I just never tweaked the end points after the initial setup... IDK. But it makes me wonder, just how does one adjust the end points without having to do a self check just to see how far the travel has changed? It's almost like I want to put a non-stabilized Rx in the plane, just on the bench, to get the endpoints tweaked to where I want them, then reinstall the stabilized Rx and do one self check and be done with it.

Can anyone shed some light on this? It seems like I'm missing something or not fully understanding how end points are set in the model vs end points learned by the stabilized Rx.

Thanks, Scott

 

[Flying Dutchman]

Not sure about #1, but I believe it's stored in the Tx, not the Rx. As far as I know the Rx does not store anything other than binding and perhaps calibration info.

Regarding #2, I tried to duplicate the problem you describe, but it does not happen on my radio (QX7 running OTX 2.3.11) and SR8. I also have a 3-pos switch for Hi/Med/Lo and was able to change the Min/Max values on my OUTPUTS screen by both small and large amounts without affecting the travel of my ailerons. No need to do repeated Self Checks. Since you have multiple units, are you able to replicate the problem on the other planes?

 

[Scottand1000]

Not sure about #1, but I believe it's stored in the Tx, not the Rx. As far as I know the Rx does not store anything other than binding and perhaps calibration info.

Regarding #2, I tried to duplicate the problem you describe, but it does not happen on my radio (QX7 running OTX 2.3.11) and SR8. I also have a 3-pos switch for Hi/Med/Lo and was able to change the Min/Max values on my OUTPUTS screen by both small and large amounts without affecting the travel of my ailerons. No need to do repeated Self Checks. Since you have multiple units, are you able to replicate the problem on the other planes?

FD, thanks for your reply. Regarding #2:

I'm not sure what you are saying. You changed the min/max values on the TX OUPUTS screen "without affecting the travel of my ailerons"? Well, this is the same behavior I am seeing.

Maybe I didn't express my situation properly, initially. I'll try again by describing my scenario as best I recall it: I initially set up my full aileron travel by eyeballing the deflections. I actually used a cardboard template cut with and angle as a way of setting equal up/down deflection, did it on both left/right ailerons. But, it's still kind of eyeballing it... So that's how the plane and its end points were set originally. I'm in FL for the winter and a lot of my tools are back in New England, tools like my deflection meter. I decided to order another deflection meter for FL; it came the other week. So I used it to check (re-check?) my aileron deflections and found I needed a little more up travel on one aileron. The meter is more accurate than eyeballing with a cardboard template. This is when I tried to bump up the aileron end point. I had it set to about 85% originally (as best I recall), and it needed just a small amount more travel. It wasn't like I was trying to go past 100% (which could be an issue of another kind). I found as I increased the end point from 85% to maybe 95%, and then to 100% for hahas, it didn't change the amount of full aileron deflection at all. When I'm doing this, I have stabilization turned off, I have my rate switch set to high, I'm holding the aileron stick to full up defection, and I'm turning up the end point. Nothing is happening. However, after a self-check, now the extra aileron travel is seen on the defection meter. In other words, I needed a self-check for the new, increased end point to be realized, even with the stabilization turned off. I played around more and found if I turned down the end point to something very noticeable like 50%, again the aileron wasn't showing any of the effects until I did a self-check. So, it sounds like your setup is doing the same thing mine is, if I understand you correctly?

I don't remember anything like this happening on my previous stabilized RX setups... But I'm not sure I ever tried it either... I don't think I want to monkey with any planes I currently have set up and working well with stabilized RX's. I'd rather leave those setups alone. But I do have a second plane I am currently in the middle of building with the same type of SR8 RX. I'll use this opportunity to try to duplicate the issue on a different but identical setup; i.e. same TX, same type SR8 RX (flashed with the same firmware as the first RX). I'll try an experiment where I just set up the RX with say only two servos for simplicity, maybe try setting the end points to 50%, self-check, then try bumping up the end points to 100% and see what happens. I can see this failing because, how would the RX know travel extents any further than what it learn on the initial self-check??? Then I'll try the opposite; set everything up at 100% end points, self-check, and then cut down the end points to say 50%, and see what happens. I'll be careful to note all the things I find and write back. I guess what's confusing me is shouldn't the SR8 act like a non-stabilized RX when the stabilization is turned off? How come the aileron travel doesn't change when stabilization is turned off, I'm holding full stick, and I'm bumping the end point value up and down?

Thank again for your help. I appreciate you trying to duplicate the issue.

 

[Flying Dutchman]

I guess I was not very clear with my 'affecting ailerons' statement. I meant to say that my Hi/Med/Lo switch works as intended, at all end points set in the OUTPUTS screen.

Here is my setup (on an Avanti EDF):
- Max aileron travel is set at 60% (-60 to +60) in the OUTPUTS screen
- 3-pos switch (SC) sets the weight of CH1 to 100/85/70 in the MIXES screen

When I changed the travel in the OUTPUTS screen to 40% or 80%, the switch would dutifully adjust the new max travel to 100/85/70 of the new value, without any further Self Checks. Hope this helps.