Nice, i have all the informations i need thanks

Jim maybe a Reading error on the schematics (D3 on xiao, grounding of MOSFET, direct ,3,3v or vcc to solenoid and output if mosfet... I have made the same wiring i Can hear a very very small noise but have t done the tube or bucket testings. I have a frequency change following ppm pulse change on a servo tester. I 've cheched in comparison , with bert kit and it's fast l'ESS noisy. I was suspecting Fake or faulty MOSFET i've received New batch or vishay i will retest. Or my reading or tutorial in colors if wiring, schematics...IS wrong. D3 IS well declared in Arduino ide sketch.... Maybe Dave Can check. I will go ahead on a New xiao MOSFET etc and tell you.
Fxdr

This is not clear to me Fxdr, please clarify.
Do you mean that I might have made a mistake with the wiring connections?

That suggests to my thinking that the MosFet is ok and is driving the solenoid.
Do the tube/air/fuel test and post back the result please?

Jim.

Your analysis is unfortunately incorrect. Temperature has very little influence on how the engine runs, except for the first 5 seconds after start or so, but even that effect is minimal.

For a good analysis, I need more info. If you followed the advise, you programmed a slighly slow throttle servo movement? I normally start with 0,5~1 second "slow down" in only the up stroke. This means that when you open the throttle quickly, the servo moves a bit slower, and when you colse the throttle quickly, the servo moves its normal max speed.
This slowdown is normally NOT applied to the fuel mix function. This means that when you open the throttle quickly, fuel is opened a bit more quick than the throttle itself.
Please test if the problem is also happening when you SLOWLY open the throttle.
If the engine responds normal to slow throttle movements, the curve is good. If the engine stumbles on fast throttle changes and it sounds ritch, most likely you need to make the servo a little bit faster. If it responds lean, you need to make the servo a bit slower.

Only if the engine goes rich when you move the throttle slowly (or in SMALL steps), that is when you need to adjust the fuel curve.

Adjustments to the fuel curve must be SMALL adjustments.

On the bolded: Do NOT do this in flight!!! Fly, check at which throttle stick position you think you need a correction, if necessary, ask a friend to mark that stick position for you, land the plane, and either kill the engine or tie the plane down, THEN make the correction.

The New MOSFET replaced the one from Aliexpress and it works flawlessly si AT 57 yes old i assume i Can still be usable
I've wired a black solenoid to check and it works

Yeepee



UOTE=Fxdr;12809306]Jim maybe a Reading error on the schematics (D3 on xiao, grounding of MOSFET, direct ,3,3v or vcc to solenoid and output if mosfet... I have made the same wiring i Can hear a very very small noise but have t done the tube or bucket testings. I have a frequency change following ppm pulse change on a servo tester. I 've cheched in comparison , with bert kit and it's fast l'ESS noisy. I was suspecting Fake or faulty MOSFET i've received New batch or vishay i will retest. Or my reading or tutorial in colors if wiring, schematics...IS wrong. D3 IS well declared in Arduino ide sketch.... Maybe Dave Can check. I will go ahead on a New xiao MOSFET etc and tell you.
Fxdr[/QUOTE]

Please post a link to that MosFet from AliExpress.

What does this mean?

i bought some New vishay on amazon in France or Germany ( supplier vue chipmatket) because all those ordered on Ali were not functionnal

Yes, fake parts are the norm these days, unless ordering from a reputable component supplier. There are fake components on Amazon as well. Glad you found working ones.

Yes, I put 0.5s of slow up on the throttle stick.
And yes with slowly movement to move up the throttle the engine seems rich few seconds.
So I need small adjustment on curve.
It's better to adjust first the point from where I start to move up or the next point from where I started?

Ok I will do the adjustment on the ground, and not during flight.

Take the plane airborne, ask for a friend to assist (he can pay attention to the exact throttle stick position). If your TX has index marks on the stick (most TX have) use those, if not, open a graph or screen on the display so your friend can as exact as possible observe the stick position.
Fly at a constant throttle setting where the engine still runs correct, keep it there for say, 15 seconds. Increase throttle by say, 10% or one index mark, and keep it there for another 15 seconds to observe what needs to be done with the curve,leaner or richer. In case of doubt, always FIRST try richer, to confirm whether that deteriorates engine behaviour.
Carefully check, at which stick position the rich running first becomes noticable in flight, and carefully adjust accordingly. Continue this for the entire range that you suspect of being "less optimal"

Reason for not doing adjustments in flight, is because "just right" is very close to "flame out due fuel starvation" and it is easy to overshoot, after which you have a deadstick landing to manage... Better to carefully creep up on perfect than to overshoot into fuel starvation.

This all sounds a bit complicated, but trust me, once you have done one or two engines and start to get a feel for it, know what to look (or better: listen) for, and what it means, it becomes pretty easy. Ask Guillaume... :D

In OTX, it's easy to set up a switch to audibly report the throttle position while in flight, no helper needed. My radio is all set up to tune my solenoid converted engines for flight and they run fine on the ground. Some day I'll be able to get back to the hobby and tune them for flight.

Dammit... I never thought of that... Where's the "hit oneself on head with hammer" smiley when I need one?

I SO hope for you to get back in the active part of the hobby, Len.
Don't forget: Set that needle ONE click rich from peak for that first flight...

I must give credit where due.........IIRC, Raleighcopter mentioned it somewhere along the way.

Very possible... I'm just stupid for not even thinking about that myself: I have used, and in some cases still use the call annunciation function myself, so it is plain silly of me regardless...

It's a great tip, should be remembered...

Do you set it up to report the throttle position in, for example, 10% increments?
And subsequently create the voice announcements to suit?

You can... but you can also set it up to announce the momentaneous value at the flip of a switch (preferrably the selfreturning switch right side furthest to the bottom). So you hit the switch and hear where the throttle is at.
You can ALSO set it up such that at the passing of each desired increment, a short beep is sounded.
That is entirely up to you, since it is openTX :D

I personally have the habit of using the index marks on the side of the stock Taranis. There are 9 indexes at the side of the gymbal, that coincide with increments of 25 points on a scale of -100 to +100.
I set up my curves, both fuel and throttle, to have 9 points, so each point on the curve corresponds with an index mark of the stick.

I have several times made the mistake of NOT doing that, and it makes it near impossible to set a decent curve, if you do not have exactly defined increments and exact corresponding points on the curve, for the simple reason that if your stick is at point 5, but you are inadvertently changing the curve at 4 or 6, nothing happens... Engine RPM, exhaust note, etc, don't change
It really pays off here to position the stick on one of the points as accurate as possible before judging the engine and changing the mixture, because if the stick is even slightly off the mark, the effect of a change at the corresponding point, will be less noticable, and therefore the correction you make will be likely a bit larger than you intended.

In OpenTX you can of course set up a 17 point curve that also covers the points in the middle between index marks, but to be totally honest, I have never noticed any significant or noticable improvement.

It usually is a good idea to check the box "smooth" in the individual curve settings.

for those with non-OpenTX sets:
Some TX' have curves with a fixed number of points that you have to make do with.
7-point curves like on some Futaba and Spektrum sets are doable and will give a decent result (if you overcome the handicap of not having an exact correlation between index marks and curve points), 5 point curves as on the lower priced or older Futaba's , in general it really becomes apparent that the curve cannot be funed fine enough for a really smooth engine response. Flyable enough, acceptable enough, but it won't make you proud. It is worth considering purchasing a different TX because of this, necessary it is NOT.

Ok, I have since realised that "play value" can be selected in the Special function that applies, most likely as activated by a logical switch..
Old man asleep at the wheel ..again! :D

Why does the "smooth" box check, as below, not make that unnecessary? Any arbitrary position along the curve should be accessible and adjustable, should it not?
As I understand curves, this is the very reason "smooth" is an option. The "points" are only required to set up a actual digitally programmed curve response which functions, as it should, at any position along it's trajectory. Any of these might be between the set up "points".
While writing this, I am aware there is something fundamental I must be missing, because I have encountered this before, but never asked questions.
If so, please set me straight on this?

Edit:
I think I can answer my own question here.
To process or modify the curve in OTX, one of the original set up points has to be selected, as you describe, by positioning the throttle stick accordingly. Or, approximately so.
Looking at a curve in OTX made that clear to me.
The curve cannot be modified by selecting between points with the cursor.

Jim.
https://cimg8.ibsrv.net/gimg/www.rcu...e302a3f042.png

The smooth function only "rounds the curves". Unchecked, the curve consistst of straight lines connecting each point, cheecking the smooth box makes it a smoother line with "turns" instead of "angles".
Checking the smooth box does NOT allow for setting any arbitrary position inbetween points.

Yes that's correct, Jim. You can't make adjustments between points....BUT....you can relocate the points. I group my curve points such that they are closer together where needed....eg in the bottom half of the curve, where throttle transition is more problematic. So for a 9 point curve I would have 5 points between idle and just below 1/2 throttle, and four points above half throttle. Alternatively, you can simply use more points eg 12 points.

OTX question?
 

Ok, I've got that now.

Quote:

---

Yes that's correct, Jim. You can't make adjustments between points....BUT....you can relocate the points. I group my curve points such that they are closer together where needed....eg in the bottom half of the curve, where throttle transition is more problematic. So for a 9 point curve I would have 5 points between idle and just below 1/2 throttle, and four points above half throttle. Alternatively, you can simply use more points eg 12 points.......

---

That explains a lot.......... I expect that I will be asking more questions about that later. Thanks.

However, a resulting question arises in my mind, which is more of an OpenTx question than anything else.
If I use Raleighcopters "Gemini" model set up as an example, how does the output position of channel 5 determine when and if a OTX set up point is effectively selected for adjustment purposes via S2?

https://cimg7.ibsrv.net/gimg/www.rcu...88909667a9.png

I haven't messed with OTX in two years, due to circumstances here. I also have not looked at Raleighcopter's code for his Gemini twin, however, that kind of looks like programming for a choke/fuel enrichment function? Not sure. We would need to know what GV1 (global variable) is set to.

To answer your question about how to tell if the throttle is at a set point......you view that in the curve mix (CVx) on the curve channel page. As long as your curve is slaved to the throttle stick....and not slaved to the throttle channel output you'll be fine.

It is set to -100. As per his full .otx file here: https://www.rcgroups.com/forums/show...&postcount=618

What, do that while you are flying?

I suspect that I have been asking the wrong questions, as we appear to be talking past each other.
I will attempt to re-phrase my question:

The curve points selected in an OTX capable transmitter such as a Taranis et. al. are adjusted in the curves page.
How does the position of the throttle stick combined with the setting of S2 adjust one of the selected "points" on the smoothed curve in the curves page?
Can the adjusted (moved) point in question then be seen to be at a slightly different position when viewed in the curves page? (Page 7/12 in OTX/Taranis).
Should I move this question over to the OpenTx dedicated thread over on rcgroups.com?

Edit:
I was unable to simulate this in Companion 2.3.15.

Jim.

That indeed is a miscommunication, the throttle stick position in itself has nothing to do with the actual adjustment of any point in the curve.
The points on the curve are adjusted by moving the cursor to the value you want to adjust, and push the + and - buttons. Stickposition, or S2 both have NOTHING to do with that.

In order to set the curve at the points 1-9 (-100, -75, -50 etc etc up to +100), the engine has to be operated at these points as accurately as possible.
When doing a testrun (testflight) in order to judge engine behaviour or to determine which point needs correction, "approximately midstick", or "approximately 1/4 throttle" are not good enough, I cannot stress this enough, being inaccurate here causes one to achieve different results from the same order of magnitude corrections, and you'll be chasing your own tail forever.

I don't know how to further explain this. All I can say is, that I HAVE been chasing my own tail quite a bit at times...

I am much relieved to now know that I had understood it all incorrectly.........strange to say!

Ok, understood.
But.....what function does S2 provide?

Ok. So then, assessment is only done during flight, then adjustment is only made when the plane is on the ground. (via S2?) Is this correct?

Thanks for sticking with me on this...it must appear that I am a bit obtuse......which is probably correct!

Jim.

Can't help you with that as it is not my programming.
Personally, I simply use the buttons at the side of the display of my Taranis to do all settings.

Initial adjustments are done on the ground, making sure the engine runs a touch rich, for reason that virtually ALL engines lean out a bit in the air: the prop unloads, allowing the engine to run a higher RPM for any given throttle position, compared to running on the ground with that same throttle position.
This increases air draw, and although fuel draw increases with airdraw, this is not 100% linear.***
So the trick is to run the throttle positions that coincide with the curve points, and carefully listen for how the engine runs. Adjust when necessary but do so on the ground for safety reasons. Check transitions from point to point as well, but usually, when the curve is good, transition is good too,



No, not at all, it is at times pretty difficult matter to grasp mentally, and it took me several years to get where I am now, and still discovering new things every now and then.
So I'm happy to stick with you. Part of the learning proces, also for me.

***See next post for a bit more on that