Speed control problem?

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Buddy of mine has a P3 Pro. Was flying about 30' when it hit a duck and crashed. He said after that 1 motor does not "speedup" like the other 3. He took 1 of the good motors and placed it that the bad motor slot and did same thing. requesting input on this matter for him, thx, Kel
 
Well that's the best (only) way for the user to determine ESC or Motor problem. Especially if the motor replaced works fine in a new position.
Seems like a Main PCB, which contains the ESCs, needs replacing.
 
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Well that's the best (only) way for the user to determine ESC or Motor problem. Especially if the motor replaced works fine in a new position.
Seems like a Main PCB, which contains the ESCs, needs replacing.

Sorry if I wasn't clear, when he put the good motor in the bad motor spot, it did the same thing as the "bad motor", it did NOT speed up as the others.
 
Yes, understood. To further prove this the motor moved from 'bad' arm should work fine in a different arm.
Conclusion... bad ESC... aircraft needs new main PCB.
 
When you say "doesn't speed up" like others does the motor run? Has he tried to take off? Usually a bad ESC will trigger an in app warning.

As has been said a know good motor performing similarly in the suspect arm is reliably suggestive of the need for main board replacement. It's hard to know what's going on from your description however- it's not uncommon for motors to seemingly run at different speeds pre launch.
 
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WTB makes a good additional point. I expected that a rev-up test was the case. Because of the closed-loop control system simple idling tests CAN be inconclusive.
 
When you say "doesn't speed up" like others does the motor run? Has he tried to take off? Usually a bad ESC will trigger an in app warning.

As has been said a know good motor performing similarly in the suspect arm is reliably suggestive of the need for main board replacement. It's hard to know what's going on from your description however- it's not uncommon for motors to seemingly run at different speeds pre launch.


He said at take-off it immediately veers off to the side?
 
How much experience does your friend have? It's not uncommon for inexperienced operators to complain of this effect where they are a little on the tentative side with the sticks when taking off. As you likely know you need to get up quick and out if the ground effect.

If the AC can maintain a hover with no ESC errors reported all is probably good with the propulsion system.

What is most likely in this case is structural damage to the shell and/or IMU issues. Try an IMU calibration and look at the mod values. You may even have a stuck IMU and will need to give it a careful but deliberate tap in the opposite direction to impact to free it up.
 
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How much experience does your friend have? It's not uncommon for inexperienced operators to complain of this effect where they are a little on the tentative side with the sticks when taking off. As you likely know you need to get up quick and out if the ground effect.

If the AC can maintain a hover with no ESC errors reported all is probably good with the propulsion system.

What is most likely in this case is structural damage to the shell and/or IMU issues. Try an IMU calibration and look at the mod values. You may even have a stuck IMU and will need to give it a careful but deliberate tap in the opposite direction to impact to free it up.
Pretty sure he has flown quite a bit, the issue started right after the encounter with flying duck. He is on this sight , going to tell him to join the conversation...thanks.
 
Thanks for the good ideas. I'm the slap that that was hunted down by a vicious duck. I'm not an expert but wouldn't call myself a newbie. After crash landing checked the system. All seemed to be good. Tried to take off and drone flew up about 2 feet then flipped upside down. Tried researching some problems. Took drone apart. Tested motors. One slower. Switched motors. Seemed to work. Put everything back together. Tested again, same result, drone flew up then flipped upside down. I'm thinking some kind of speed control to arm? Any thoughts? I saw the advice for a new PCB. Thanks, I'll look into it
 
Thanks for the good ideas. I'm the slap that that was hunted down by a vicious duck. I'm not an expert but wouldn't call myself a newbie. After crash landing checked the system. All seemed to be good. Tried to take off and drone flew up about 2 feet then flipped upside down. Tried researching some problems. Took drone apart. Tested motors. One slower. Switched motors. Seemed to work. Put everything back together. Tested again, same result, drone flew up then flipped upside down. I'm thinking some kind of speed control to arm? Any thoughts? I saw the advice for a new PCB. Thanks, I'll look into it
Have you calibrated the IMU? What are the mid vakues for IMU in the sensor status screen?
 
Ok, just found a good site to show me what to do for the IMU. I'll look into it tomorrow. Thanks for the suggestion.
 
I couldn't tell you now. Haven't played with it since last fail. What should I be looking for?
x and y axis 0 with Z being gravity. Check the props are spinning in the right directions also (you may have switched phases when swapping motors (wrong motor for wrong arm or wiring error).
 
How much experience does your friend have? It's not uncommon for inexperienced operators to complain of this effect where they are a little on the tentative side with the sticks when taking off. As you likely know you need to get up quick and out if the ground effect.

If the AC can maintain a hover with no ESC errors reported all is probably good with the propulsion system.

What is most likely in this case is structural damage to the shell and/or IMU issues. Try an IMU calibration and look at the mod values. You may even have a stuck IMU and will need to give it a careful but deliberate tap in the opposite direction to impact to free it up.
As I read through this thread, this is exactly what I was going to suggest, WTB. I took off from a slope a couple of days ago and on idle, and the two forward motors were hardly moving. Throttled-up and away it went, in a perfectly vertical manner.
 

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