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Pumpkin drop event

How do you limit maximum throttle setting? OpenTX/9XR

#1
Hi,

I can't for the life of me figure out how to limit the maximum throttle setting on OpenTX.

I want to be able to limit the maximum throttle to limit the maximum Amp draw so that I can stay under the 80% threshold of my motor. I have a watt-meter so know roughly where I want the maximum to be.

I obviously tried googling, have tried the Limits page on the radio, and reduced the high setting, and tried the weightings, looked through settings in Companion9X, but without getting the desired effect.

I've managed to configure 4 channels, with flapperons, pots to adjust flapperon rates in take off and landing mode, elevons on my flying wing... but can't figure out how to do something as simple as reduce the max throttle!

Any advice or pointing me in the right direction would be great.

Cheers,
Tim.
 
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#3
Hi xuzme720,

Radio or Companion9X, can't figure out how to do it on either of them ?! Any ideas where to look or what I should be doing?

I've managed to configure 4 channels, with flapperons, pots to adjust flapperon rates in take off and landing mode, elevons on my flying wing... but can't figure out how to do something as simple as reduce the max throttle!

Cheers,
Tim.
 
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xuzme720

Dedicated foam bender
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#4
I wish I could help more but I've never used companion9X myself. There should be an endpoint adjustment in there somewhere that will let you set a throttle limit. Maybe someone with more experience with C9X can be more specific.
 

jhitesma

Some guy in the desert
Mentor
#6
I'm still on er9x - haven't tried openTX so I can't be of too much help. But have you tried asking on the openRC forums since that's more or less the "official" forums for 9x custom software? I've inquired over there are issues I've run into a few time and they've always been really friendly and helpful.
 

ofiesens2

Professional noob
#7
I'm really not sure if this will work with OpenTx, but try setting the limits on throttle to 100, downloading the eEprom to the Tx, connect the motor, ESC, and battery into the receiver, turn your throttle stick to full, connect the battery, and move the stick to zero. Here is a video on it if my comment made no sense.
 

Ron B

Posted a thousand or more times
#8
ok guy's here is a noob who is having to learn every thing.
I had to set my esc throttle as it would not respond until 1/2 throttle so I set it and have full range now so if Snuffy were to set the esc only using 3/4 or very slightly more would that give him what he wants to do?
 
#9
I've been playing with it and can get so far with a few options, none appear to be the correct way to do this:

  1. If the Throttle channel is set to Weight = 80%, and Offset = -30, it gives a rough estimation of a 75% of the total, and the throttle stick can be used over the full travel to control that 75%, kinda works, but not very accurate or elegant.
  2. If I change the Max Limit for the channel to -25 (zero is the centre position), that allows me to use 0-37.5% of the original total output, but when I move the stick from the bottom position, to 37.5% of total vertical travel, that's it, throttle max. It doesn't allow me to use the full bottom to top travel on the stick to control that 37.5% limited throttle, nor allow me to limit to less than 37.5% if I wanted to; -25 is the lowest it will allow me to go.
  3. Tried playing with curves and that didn't seem to work either.
 
#10
I'm really not sure if this will work with OpenTx, but try setting the limits on throttle to 100, downloading the eEprom to the Tx, connect the motor, ESC, and battery into the receiver, turn your throttle stick to full, connect the battery, and move the stick to zero.
Hi ofiesens2, I'm not having an issue binding or calibrating the sticks; I just want to limit the output to a predetermined maximum throttle/speed setting.
 
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#11
ok guy's here is a noob who is having to learn every thing.
I had to set my esc throttle as it would not respond until 1/2 throttle so I set it and have full range now so if Snuffy were to set the esc only using 3/4 or very slightly more would that give him what he wants to do?
Thanks Ron B, I had thought of that and I believe it can be done that way yes, (ESC programming is next on my todo list), however, I will be using the same ESC on multiple planes, so want to configure the throttle limit on the Model memory for this particular plane on my 9XR radio.
 
#12
I'm still on er9x - haven't tried openTX so I can't be of too much help. But have you tried asking on the openRC forums since that's more or less the "official" forums for 9x custom software? I've inquired over there are issues I've run into a few time and they've always been really friendly and helpful.
Yep, that's my next port of call, thanks. I thought I'd try here first as it's my favourite :) I'm going to watch some more general videos on OpenTX programming, maybe something will pop out at me.
 

xuzme720

Dedicated foam bender
Mentor
#13
There is no end point adjustment in the menus? That seems very strange...
There should be a travel adjustment usually listed as positive and negative (+ & -) with a default as 100 for each channel. Look for a listing of channels that the value changes from + to - when you move the stick for that channel. Setting the positive on the throttle to +60 should give you the 80% you're looking for unless the throttle channel only runs from zero to +100, instead of -100 to +100, then you can just use +80. Let me see if I can find a programming video that might help...
 

xuzme720

Dedicated foam bender
Mentor
#14
I found this one that goes through the menus at the beginning. The rest of the video probably won't help as he's completely lost in programming...
Where he focuses in at about :50, you see the end point adjustments (E.points). Change the throttle channel percentage to 60% on the right or high setting and see if that works for you.

 
#15
I found this one that goes through the menus at the beginning. The rest of the video probably won't help as he's completely lost in programming...
Where he focuses in at about :50, you see the end point adjustments (E.points). Change the throttle channel percentage to 60% on the right or high setting and see if that works for you.

companion9x - EEPROM Editor - firmware openTx for 9XR with M128 chip_2014-02-24_17-06-49.png

As you can see the most the 'Max' can be limited to is -25; so if you imagine the throttle range being 0-100 on the first half of the stick's throw, i.e. completely down, to horizontal, and the second half, 0-100 again, throttle stick position horizontal to vertical, then the most the range can be limited to is all the way down, to the first 0-75, i.e. just below horizontal. But you then that throttle range is compressed into that short range of travel. I think I may not be explaining myself very well, so ignore me if that's not clear.

This makes me think that the curves option may be the way to go, but I'm not yet sure how to do that.
 

xuzme720

Dedicated foam bender
Mentor
#16
Ok. the center stick position is(or should be ) zero. By adjusting the endpoints, or throw if you are doing this on a servo channel, you tell the radio what the limits are. If you set the endpoint at 80%, when you move the stick all the way to the right, the servo will only move to 80% of it's full throw. It actually works like dual rates but it sets an all around maximum throw. Doing it on the throttle channel will limit how far the ESC can throttle up. One thing to keep in mind, if you set the endpoints and then recalibrate the ESC, the ESC will see the reduced throw as full throttle again and will negate any benefit you gained with a reduced top end of throw.
Back to what you were asking...
Travel is measured like this -100 bottom----0 center-----(+)100 top or full throttle.
If you set max at -25 you give the radio only 75 units of movement or travel to work with so now....
-100 still bottom---- -62.5 center----- -25 top or full throttle. So, full throttle on the radio will give you less than half throttle of what you had before. Here's where it get really weird. Now if you re-calibrate the ESC, you'll have the full range you had before you adjusted the endpoints, just with reduced resolution.
Best bet for you to get the reduced top end of the throttle easily, without resorting to curves, which can also work, is to set the endpoints to -100 and 100. Calibrate the ESC (throttle stick up full, power on ESC, throttle stick to down full, etc.). Once you have the ESC calibrated, change the max number to 60%. This will reduce the throw and limit your ESC to about 80% of it's full power setting.
Does that help any or have I just confused you more?
 
#17
Ok. the center stick position is(or should be ) zero. By adjusting the endpoints, or throw if you are doing this on a servo channel, you tell the radio what the limits are. If you set the endpoint at 80%, when you move the stick all the way to the right, the servo will only move to 80% of it's full throw. It actually works like dual rates but it sets an all around maximum throw. Doing it on the throttle channel will limit how far the ESC can throttle up. One thing to keep in mind, if you set the endpoints and then recalibrate the ESC, the ESC will see the reduced throw as full throttle again and will negate any benefit you gained with a reduced top end of throw.
Back to what you were asking...
Travel is measured like this -100 bottom----0 center-----(+)100 top or full throttle.
If you set max at -25 you give the radio only 75 units of movement or travel to work with so now....
-100 still bottom---- -62.5 center----- -25 top or full throttle. So, full throttle on the radio will give you less than half throttle of what you had before. Here's where it get really weird. Now if you re-calibrate the ESC, you'll have the full range you had before you adjusted the endpoints, just with reduced resolution.
Best bet for you to get the reduced top end of the throttle easily, without resorting to curves, which can also work, is to set the endpoints to -100 and 100. Calibrate the ESC (throttle stick up full, power on ESC, throttle stick to down full, etc.). Once you have the ESC calibrated, change the max number to 60%. This will reduce the throw and limit your ESC to about 80% of it's full power setting.
Does that help any or have I just confused you more?
Nope, you explained that better than I did; your -100 - 0 - +100 and the 75 units of movement is exactly what I was poorly trying to explain. :)

I think I am limited in the amount of throttle reduction I can get, but that may be enough for what I need and at least I'm not way off track in my thinking.

Thanks for your time, it's appreciated :)
 

xuzme720

Dedicated foam bender
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#18
Just curious but what makes you say that you are limited in throttle reduction? I thought you were only looking for a little bit?
 
#19
Just curious but what makes you say that you are limited in throttle reduction? I thought you were only looking for a little bit?
Sorry, I don't seem to be getting the email updates like I'm supposed to so missed your post; the same on another post I made! I saw you'd also given some advice on that one :)

It's all good, I had my first flight on the Versa Wing at the weekend; scary but great! Much faster (and more difficult) than playing on the Simulators with similar models. Crashed it 20 feet from take-off on first attempt, but threw it at a higher angle from there and it was great. Twitchy as anything though; need to dial down the throws and up the expo on the next go, but for a first flight ever, thought I did ok; managed to get it up and flying around, managed some sketchy low passes, and did some nice floaty landings. The nose is a bit bashed in now, but I can say I'm hooked.

In answer to your question, it started out as practical to limit the throttle, but then became a bit more theoretical/educational/how-would-you. Turns out in the end I didn't need to limit the throttle in this case, but for next time I now know how. :)

Saw your video on throwing the Versa Wing... should have watched that before crashing mine!
 

xuzme720

Dedicated foam bender
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#20
Yes the Versa does take some getting used to when launching a wing for the first time. I will say this though, even after all that, she still flies beautifully, even if she is a little "softer" in a few places...