Unusual observation

kaos · Post by **kaos** » Wed Oct 28, 2015 3:31 pm

this question does not seem to fit any where so I put it here.
I got a model that was set up before. After I flashed the Ersky r178 ti R218 latest test version and to check on setting (after I calibrated the sticks and pots). I found an interesting phenomenon I can't explain.
When I was testing the throttle, throttle kill off and raise thorttle, no problem, then I lower the throttle to the lowest point which supposedly should stop the engine, but it didn't there is a tiny little current still going through making the prop keep running just a little. But put the throttle kill on. It stops the engine completely.
My THR is set at -100 when on. I thought something wrong with the motor or ESC. But I fooled around a little and found out if I put the limit on the Thr to -102 or -103, that will stop the engine when throttle stick is all the way down. So that solve the issue. But I could not figure out why. Becaue my THR switch is set at -100 and it kill the throttle completely, but the Thr ch has to be at -102 or -103 to kill the throttle completely.
Any idea? bad pot for Thr? It is consistent.

Post by **Kilrah** » Wed Oct 28, 2015 3:55 pm

Look at the output percentages screen on the radio and see what differs between idle / cut off and idle / cut on.

Post by **jhsa** » Wed Oct 28, 2015 4:18 pm

And if that motor is stopping only when it hit 100%, then that ESC needs to be calibrated to the radio

João

kaos · Post by **kaos** » Wed Oct 28, 2015 6:51 pm

Very interesting.
the mix for THR is : R -100 HALF THR
when THR is on, diag always shows -103 why when mix is -100 HALF? (the limit of Thr at this time is set at -103 -> 100)
When THR is off, Thr down, diag shows 98.6 some times 99.8, 99.1, 99.5

Ah, could be the ESC calibration is needed. Does that mean we need to recalibrate the ESC every time we reflash the FW and recalibrate the sticks? I don't remember I need to do that before.
So I recalibrated the ESC, yes, now the limit of Thr is set at -100 -> 100
the diag shows:
THR on -100, THR off -98.3 and the motor will stop when power up and down.
How the calibration of ESC change the number of tx output setting? I thought ESC responds to the stick output. But now it seems to me, the stick output is responding to ESC calibration.
I am missing something here.
I am just curious about this. Don't recall this happened before.

BUT after these electronics sitting there for > 1 yr, I guess they gets mold build up?

or May be my brain got mold build up.

Cause I found my pan and tilt servo controlled by my goggle is also some what glitching when I move my goggle. It WAS smooth 1 1/2 yr ago.

Post by **MikeB** » Wed Oct 28, 2015 7:01 pm

Try re-calibrating your sticks. I have seen a situation where when you put the throttle stick fully down, then move it left and right (rudder, mode 2), the throttle position changes slightly. If you do this while calibrating, this couild mean fully down in the centre is not -100% as this occurs with the stick right or left as well.

Mike.

Post by **jhsa** » Wed Oct 28, 2015 7:53 pm

ESC calibration is needed always when you use it with a different radio/module setup.

The ESC will learn the min and max travel from the radio, save it and use it. If you connect it to another radio the channels might have different max and min values, so you will need to calibrate it again..

João

kaos · Post by **kaos** » Wed Oct 28, 2015 9:08 pm

MikeB wrote:Try re-calibrating your sticks. I have seen a situation where when you put the throttle stick fully down, then move it left and right (rudder, mode 2), the throttle position changes slightly. If you do this while calibrating, this couild mean fully down in the centre is not -100% as this occurs with the stick right or left as well.
Mike.

Ah ha! That's it. I think when I do calibration, a lot of times I move the stick in the peripheral circular movement trying to hit where ever the longest reach may be. I 'thought' during calibration the tx remember what is the highest and the lowest out put. so during calibration we should just move the stick straight up/down, left/right instead of moving laterally to the corner too?

I guess this is the 1st time after I did all those recalibration/flashing FW, I observed this on a previously set model that affected the Thr at the very end, not much just a tad. May be it happens on servo as well, just so minor, normally I would not even notice it if it is on the servo. This was very minor, the motor won't start turning when I turn off THR when Thr is at bottom, only when the Thr is down after motor has run and had some momentum and you see it is not fully stopped just like a little trickling kept the motor running at a low spd. Actually you can hear a little clicking sound as well. I, for a moment, thought the motor shaft is bad. When I was doing that, by changing the limit from -101 to -102 will stop the motor after Thr is down. that's how little it was.
Thx guys, at least I know my brain has no mold in it. YET!!!

Jhsa: you are saying,every time we reflash the FW I need to recalibrate the ESC on all the model again. That is going to be a chore for my 30 models there.

Daedalus66 · Post by **Daedalus66** » Wed Oct 28, 2015 9:37 pm

I almost never have to recalibrate ESCs. I use a Taranis, two 9XR Pros and a JR9303 and swap models between them. The Taranis and Pros are set to -100 for low throttle and the JR is -125. These settings give a pulse width of approx 1000us, close enough not to need recalibration of the ESCs. The throttle kill switch has the same settings.

When calibrating the sticks I simply move them from side to side and up and down, touching the stick gently to the stops. The "gently" part is important for low throttle.

You should not need to recalibrate anything when reflashing as long as you save settings before doing so.

kaos · Post by **kaos** » Wed Oct 28, 2015 10:50 pm

Yep, just pulled out a couple other model and ran a test. None of them have the situation. It is just like Mike said there is just a tad difference in calibrating the Tx. (We are talking about 1-2/100).
Of course, after 1 1/2 yr and come back with these things, I just HAVE TO pick THE MODEL that was right on the edge to test (This motor in particular is very very smooth, don't feel any thing when you turn the prop like most my motor you can feel it is going from one magnet to another, so just a trickle current kept it turning) and fool around with to get myself confused.

Post by **jhsa** » Thu Oct 29, 2015 3:40 am

kaos wrote:
Jhsa: you are saying,every time we reflash the FW I need to recalibrate the ESC on all the model again. That is going to be a chore for my 30 models there.

No, if you read my post again you will see that I didn't say that

I said that normally when you change radios you should recalibrate the ESC. That is basic electric RC knowledge

In your specific case, the fact that the ESC was starting/stopping very near the -100 value makes me believe that the ESC was never calibrated for that radio. And even if you don't remember because it was long time ago, I bet that was what happened. A well calibrated ESC would not start at that point.
Just my 2c of course..

João

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