One of my motor's spins up before the other three.
« on: April 06, 2019, 07:38:26 pm »
One of my motors spins before the other three as I raise the throttle. I have tried to recalibrate the ESC, I have gone through the max and min throttle range using the transmitter, I just don't know what to do. I must say that the ESC I'm talking about is one which was replaced for some reason, that I can't remember since I haven't flown it in a while.

It seems to have a mind of its own in the sense that whenever I plug the quad's battery in it makes the startup sequence sounds before the other three do, (the other three make the sounds together like they're meant to).

One extra note they are Emax Simon 12a ESC'S

Here is a video, please ignore the Maoam stripes  ::)  : copyandpastethishttps://youtu.be/OAz95tnrXF8
« Last Edit: April 06, 2019, 10:56:14 pm by Brandon753 »

Re: One of my motor's spins up before the other three.
« Reply #1 on: April 07, 2019, 08:06:51 am »
Are you using a self leveling mode such as Attitude?  If so, for a test, put something under the arm that starts first.  If it no longer starts first, you have found that it is not a problem.  The lowest motor (even a tiny amount) will start first because it is trying to level it and bring the lowest arm up higher.

One ESC giving it's power on sound before the others is usually caused by a faster ESC CPU or different ESC firmware startup options (e.g. delay after power on, etc.).  However it could also indicate a setup problem.  Go to the Input Output page and make sure that all banks that have ESCs connected are configured the same way.  The bit about the banks will make more sense when you look at the page.

Lastly have you seen and tried the ESC calibration documentation?
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/12058743/ESC+Calibration
« Last Edit: April 07, 2019, 07:06:16 pm by TheOtherCliff »

Re: One of my motor's spins up before the other three.
« Reply #2 on: April 07, 2019, 04:02:56 pm »
Hey, thanks for replying to my issue! My quad isn't set to attitude mode or any self-leveling type, I have it set to rate. So I don't think that is the issue. I will definitely look at what you said about it starting up faster I do believe that it's the issue, thanks again :).

Re: One of my motor's spins up before the other three.
« Reply #3 on: April 07, 2019, 07:03:32 pm »
Hm, I don't see anything about banks on the input page.

Re: One of my motor's spins up before the other three.
« Reply #4 on: April 07, 2019, 07:05:40 pm »
Oops, sorry, Output page.

Re: One of my motor's spins up before the other three.
« Reply #5 on: April 07, 2019, 07:14:12 pm »
Ok so bank channels 1 and 2 have an update rate of 490hz as where bank channels 3 and 4 have an update rate of just 50hz

Re: One of my motor's spins up before the other three.
« Reply #6 on: April 07, 2019, 07:26:22 pm »
Oh wow, so looking at it a bit more I have realised that the motor/ESC I am having issues with is set to a different bank channel than the rest, (the rest of the motors are set to bank channel 1). (as where the other one which I am having issues with is set to bank channel 2.
« Last Edit: April 07, 2019, 07:32:24 pm by Brandon753 »

Re: One of my motor's spins up before the other three.
« Reply #7 on: April 08, 2019, 03:17:48 am »
bank 1 (escs 1-3) and bank 2 (esc 4) all have the same configuration (PWM 490) so it is OK.  It was designed this way.

Imagine a tri-copter with 3 motors needing 490 and a servo needing 50.  That is why it was done that way.

Re: One of my motor's spins up before the other three.
« Reply #8 on: April 08, 2019, 08:30:16 pm »
Ah, any other reason I may be getting this issue? Or how could I look at those startup time settings you were on about?

Re: One of my motor's spins up before the other three.
« Reply #9 on: April 09, 2019, 05:13:01 am »
Different startup times are not a problem.

"One of my motors spins before the other three as I raise the throttle." is your only problem and that is usually ESC calibration / Output Neutral setting.  It could be caused by a conflicting setting, like setting that ESC output to be used to blink a status LED, etc.

Re: One of my motor's spins up before the other three.
« Reply #10 on: April 09, 2019, 07:43:43 pm »
Ok, thanks for your time. I guess I will have to do some further investigation