Ecalc says IRIS should hover at 83% throttle at sea level

Archive
1

I assumed that the IRIS was designed to hover at 50 percent at sea level?
Is that not true? What am I doing wrong?

I used the following numbers:

Rotors: 4
Weight: 1812g includes drive
ASL: 0
Battery: 3s 3300mah 35c
Controller: 20amp
Motor: RCTimer AC2830-12 850kv
Props: APC slowfly 10 4.7

I should add that at my altitude of 6000 feet ASL, it says hover@91% throttle, flight time 5 minutes and a payload of -265 grams!! Which means no Gimbal or camera.
Which does not match what I’ve seen so far. Throttle is high for sure. but super mellow flight times are 10 minutes or so

2

I am also finding that ecalc gives me a different result depending on the OS I’m running.
My iPad says it should be 83%
My Mac laptop says 76%

WTH?? :unamused:

3

difference is javascript implementation errors with ecalc(sounds like no backend all calcs in browser)

HZL

ps load up firefox on macbook compare those results

4

Seriously!
Last time I trust JavaScript to do any math for me!
That sucks!
So what is the right answer and how can you tell?
:slight_smile:

5

Chrome says 83%. This makes it really hard to rely on.

6

Javascript … faulty by design. :slight_smile:

7

Yah! Nice design concept!!

So, I’m really bugged that I cannot depend on the mathematical results from Ecalc. Is there a better application than Ecalc for designing MRs with?

I decided to try ecalc on my iPad IOS7.0.4, MBP retina OSX 10.8.5 and Win7 inside a Parallels VM in Safari, Chrome and Firefox where available. Here are the results:
iPad Retina: Firefox
: Safari

8

Yah! Nice design concept!!

Now, I’m really bugged, I cannot reproduce the error!

When I was testing earlier, I was typing the info in by hand every time and it was repeatable, every time.

I decided to do more rigorous testing, I updated all of the apps etc. and decided to use the “generate link” option in the bottom of the Ecalc page. That way I could be sure I wasn’t causing the errors. Of course, now they all agree!!!

When typing in by hand I was very careful to double and triple check over a period of a couple of days to make sure I wasn’t the one introducing the error.

So, I give, was it me? Maybe a transitory bug? Browser error? I did update everything…

Won’t be the first time I’ve been wrong and won’t be the last either, but I swear I checked…

In any case Ecalc agrees across the board now.
Here are my latest test results:

I decided to try ecalc on my iPad IOS7.0.4, MBP retina OSX 10.8.5 and Win7 inside a Parallels VM in Safari, Chrome and Firefox where available. Here are the results:
iPad Retina: Firefox = N/A
: Safari = 83%
: Chrome = 83%

MBP 15" Retina: Firefox = 83%
: Safari = 83%
: Chrome = 83%

Win7 in VM: Firefox = 83%
: Safari = N/A
: Chrome = 83%

9

strange, I entered all numbers you specified, and got 82%
Anyway - 80-anything percent is not a realistic result, it would not fly good if it was that underpowered.

10

Hey Andre!
At least I’m not completely crazy yet! :slight_smile:
Yeah, I agree. The reason I got started on this is that I live at about 1829m and my IRIS throttle is really high.

I’ve been trying to figure out if that is normal for the IRIS and it’s just that I live at altitude or what.
Ecalc says at 1829m my throttle should be 93%.

Can you recommend the log variable that would tell me what my throttle is at? and what kind of value that is?
Thanks!
Steve

11

Put your Iris in a hover for a little while. You can use Stabilize, Alt Hold, Loiter, or whatever to do so. As long as it’s not moving up and down a lot.

Then download the dataflash flight log. In the CTUN category during your hover period you’ll see the throttle out values (ThrOut). That’s your throttle percentage. For best control I usually set my THR_MID to this value in Mission Planner.