Just checked my motors speed...

[NRJ]

Gmack, DO NOT put oil in your motors!!
Sealed bearings so all you will is reduce the life of your motor.

You're right. Besides, I have a noise in a motor and I don't think that would help. Thanks.

 

[NRJ]

I went online to Walmart to find an infrared thermometer. They had one for only $15 and some change. I thought I would just go pick it up. They don't carry them in the store. So, I know that Harbor Freight would have them, but they are usually a bit higher in price. So, I checked Target, no luck. Went to Harbor Freight and they only had one for $29.97. I figured it would still be cheaper to order online from Walmart but would have to wait. But, right next to it there was a mechanic's stethoscope. I thought, hmmm, I've always wanted one of those but never really had the need. They can be used for all types of things. Plus, it was only $3.99. I thought I could listen to the motors and see if any of them sounded different.

Got it home, set up the bird, checked and tested where I would put he touch point. I put it directly on the end of the arm on the plastic just in front of each motor. I started the motors, let the bird warm up. After about 10 minutes of warming, I put the stethoscope to each of the motors (at idle only) and recorded it by placing my bluetooth headset from my cell and recorded it for one minute using the voice recorder. Pictures and sound files are attached. I did this all manually first and found the Back Left motor to be very different. It sounds to me like it has either a bad bearing or a magnet may be somewhat bad or not properly working. Then is when I recorded the motors. The Front Left, Front Right, and Back Right all sound the same. So, I recorded only the Front Right (normal sounding) and also the Back Left (abnormal sounding). These sound files are also attached for you to listen to and hopefully one of you can determine if you feel it is first a motor going bad, with either a bad bearing, or magnetic issue or something entirely different. On each sound file, it starts out loud until the microphone level is adjusted then the volume will decrease a little bit.

Link to sound file for the Front Right Motor: Dropbox - Motor Front Right 001.m4a

Link to sound file for the Back Left Motor: Dropbox - Motor Back Left 002.m4a

Let me know your thoughts. Thanks.

 

[N017RW]

Swap motor with the motor/arm of your choice.
See if sound follows.
Replace motor if sound follows.

If sound doesn't follow...
Go fly.

 

[NRJ]

Swap motor with the motor/arm of your choice.
See if sound follows.
Replace motor if sound follows.

If sound doesn't follow...
Go fly.

That is a good scenario, but way too much work. Soldering, opening the case etc. There is nothing else in the arm or near the motor that would make a noise in that area unless it was a screw. All screws are tight. So, I don't see the point. Did you hear the sound and did it sound to you like a problem? Thanks.

 

[N017RW]

Hey TEHO.
Running around buying all kinds of tools chasing this 'problem' you are fixated on bit won't attempt experimentation to investigate?

Magnets going bad?

What are looking for here?

Either you do the work and learn something or send it DJI and let them figure it out based n your analysis.

 

[NRJ]

Hey TEHO.
Running around buying all kinds of tools chasing this 'problem' you are fixated on bit won't attempt experimentation to investigate?

Magnets going bad?

What are looking for here?

Either you do the work and learn something or send it DJI and let them figure it out based n your analysis.

I don't mean to be rude but as I said, doing what you suggested only moves the noise from one location to another. It proves nothing. Only the motor apparatus can be making a noise in this area. Okay, so I do all that work, swap one motor for another in a different location and now I have moved the noisy motor to the other side. Had to put it all back together only to learn that oh, now the noise is over her where I moved it. Nothing gained by this. I may end up replacing the motor, which is better than moving a noisy motor to another location. If no one else can give me a definitive or better answer, I will probably just replace it and do the work one time only. I would like to know if anyone knows what the problem is. This helps for future situations. I know what you are saying, but might as well take out he noisy motor as there is no other thing that can make noise. Why would it disappear by moving it? Explain? Thanks.

 

[Mocho]

Listened to your recording and I don't hear any unusual noises.
What color are the windings on the motors? All nice copper looking or ?

Magnets are permanent so that's not an issue.

Winding's in the motor can leak electricity if the motor is old and the wire insulation is breaking down . The motor will sound funny, but you need special equipment to test. I doubt that is an issue though as your motors are relatively new.

Other than that all you have is a top and bottom sealed bearing. I believe you stated you don't have any lateral play, so that means the top bearing is good.
With the bottom bearing it is a little harder to detect a problem as the magnets are very strong and tend to keep the armature steady within the magnetic field.

Even though the sounds are coming from the motor you could have an ESC problem as that can change the speed and sounds coming from your motors.

Personally I'd just fly the bird until something becomes more obvious.
Why because it's too costly to try and troubleshoot a "different" sound and may cause more problems if you take it apart. Only to find out there was no problem, just a sound change.

The longer I have my P3P the more I notice all kinds of idiosyncrasies with it. One day it sounds different, the next day it doesn't hover the same, next day no range, next day video breaks up, next day the camera is tilting like crazy, next day seems to vibrate, and the list goes on....
My point being if I paid too much attention to any of these issue's it would drive me nuts and I'd never fly it.

 

[NRJ]

Listened to your recording and I don't hear any unusual noises.
What color are the wings on the motors? All nice copper looking or ?

Magnets are permanent so that's not an issue.

Winding's in the motor can leak electricity if the motor is old and the wire insulation is breaking down . The motor will sound funny, but you need special equipment to test. I doubt that is an issue though as your motors are relatively new.

Other than that all you have is a top and bottom sealed bearing. I believe you stated you don't have any lateral play, so that means the top bearing is good.
With the bottom bearing it is a little harder to detect a problem as the magnets are very strong and tend to keep the armature steady within the magnetic field.

Even though the sounds are coming from the motor you could have an ESC problem as that can change the speed and sounds coming from your motors.

Personally I'd just fly the bird until something becomes more obvious.
Why because it's too costly to try and troubleshoot a "different" sound and may cause more problems if you take it apart. Only to find out there was no problem, just a sound change.

The longer I have my P3P the more I notice all kinds of idiosyncrasies with it. One day it sounds different, the next day it doesn't hover the same, next day no range, next day video breaks up, next day the camera is tilting like crazy, next day seems to vibrate, and the list goes on....
My point being if I paid too much attention to any of these issue's it would drive me nuts and I'd never fly it.

I'm not sure what you are referring to when you say wings. But when you say copper, the only copper I see is inside the motors which are the copper magnet coils. Otherwise motors are silver. Sorry if I'm not understanding here.

You said; "Even though the sounds are coming from the motor you could have an ESC problem as that can change the speed and sounds coming from your motors." This particular motor was the fastest spinning motor of the 4 at an idle on a leveled surface. That seems odd as well, why more speed. There is a definite difference in sound on the two files I provided. Possibly you didn't have it loud enough. There was a kind of hitting sound at the lower spectrum of sound that was a constant hit, hit, hit, and much different from the other. Also, I have listened to all 4 motors and three out of the four were all the same and smooth. The 4th was not smooth. Sorry you couldn't hear it.

I agree that there are a number of things that are on and off again and a real pain. I have experienced some of those too. But most can be remedied by one day of flying others by fixing them easily. This however has been going on for some time, about 2 1/2 months or so. It is a noise that happens after a flight and when I bring it in for a landing and I'm letting it hover, it makes a fairly loud clicking or tonking sound like a motor. The motor is the only continuously moving item on the ac with any speed that would render such a noise. So, I don't want to end up with a motor going out and losing my bird. I'm trying to catch it before it happens and well I guess you could say I'm being proactive. Kind of like if you have ever driven an older classic car and it started pinging in the engine. You knew you had to take care of it. I learned from your evaluation. Thanks for your input.

 

[With The Birds]

Have you considered you may have three bad motors and one good one?

Replace the motor that's worrying you and be done with it. You may be looking for a solution that doesn't exist but you will have piece of mind flying. For your sound file analysis to be of any value you would need to look at it with a spectrum analyzer AND run the motors at identical RPM and load. The magnets can't make noise unless they are loose and the field windings can't "leak" electricity. The ESC may have an issue however that should be evident in a hover.

If the motors don't have excessive end float or axial deflection and there is no roughness when you manipulate them manually it is unlikely you have an issue.

 

[NRJ]

You may be right, there are a lot of various possibilities. Many of which I'm not familiar with. I think the gamut has been run on this issue. My next steps are to listen to the motors for another week to see if the noise I hear will disappear, change, or remain the same. I also have ordered an infrared thermometer which I will use to see if there is any excessive heat on any one motor. This will also be a learning experience. I don't mind having additional tools to help in any situation. Once done, if all remains as it currently is with one noisy motor, I will replace it. Once replaced, I will fire it up and check with Dashware, the stethoscope, and infrared thermometer to compare all the results. Then if all is well, I'll take it out for a flight.

Thanks to all of you who have provided your learned and experienced evaluations. You taught me a lot and made me think of things I didn't understand. I also learned that with Dashware and CVSViews that there are also ways to electronically monitor various items. I just have to learn how to read them. But, it's great. Thanks again. Wish me luck and happy flying to you all.

 

[GMack]

Aside, I keep the infrared thermometer next to the stove. Comes in handy for getting stuff like soup or meats up to 166 degrees, coffee below 149 (plus adding milk to cool it more), etc. Very handy kitchen appliance so it stays on the kitchen countertop.

 

[flyNfrank]

You may be right, there are a lot of various possibilities. Many of which I'm not familiar with. I think the gamut has been run on this issue. My next steps are to listen to the motors for another week to see if the noise I hear will disappear, change, or remain the same. I also have ordered an infrared thermometer which I will use to see if there is any excessive heat on any one motor. This will also be a learning experience. I don't mind having additional tools to help in any situation. Once done, if all remains as it currently is with one noisy motor, I will replace it. Once replaced, I will fire it up and check with Dashware, the stethoscope, and infrared thermometer to compare all the results. Then if all is well, I'll take it out for a flight.

Thanks to all of you who have provided your learned and experienced evaluations. You taught me a lot and made me think of things I didn't understand. I also learned that with Dashware and CVSViews that there are also ways to electronically monitor various items. I just have to learn how to read them. But, it's great. Thanks again. Wish me luck and happy flying to you all.

I don't know if it has been mentioned or not, but concerning motor noise, for some unknown reasons several pilots will land their aircraft in the grass, dirt, and other not so good areas. By doing that, it is rather easy for small debris to enter the motor and possibly cause issues. I have landed on a 3ftX3ft soft exercise mat only to help reduce any chance of taking on any debris.

I also want to mention that there was a pilot who felt he had noisy motors and he made a video showing where he applied a drop or two of lubricate into each of his motors. He had before and after sound test with in the video. I must say I'm not sure if I would do the mod, but it sure made his motors very quiet. I'm sure the thread and video are around here somewhere to where you could check it out.... It is worth viewing.

 

[Mocho]

Have you The magnets can't make noise unless they are loose and the field windings can't "leak" electricity.

It is a FACT that motor winding can and do leak.

 

[Dounin Front]

You may be right, there are a lot of various possibilities. Many of which I'm not familiar with. I think the gamut has been run on this issue. My next steps are to listen to the motors for another week to see if the noise I hear will disappear, change, or remain the same. I also have ordered an infrared thermometer which I will use to see if there is any excessive heat on any one motor. This will also be a learning experience. I don't mind having additional tools to help in any situation. Once done, if all remains as it currently is with one noisy motor, I will replace it. Once replaced, I will fire it up and check with Dashware, the stethoscope, and infrared thermometer to compare all the results. Then if all is well, I'll take it out for a flight.

Thanks to all of you who have provided your learned and experienced evaluations. You taught me a lot and made me think of things I didn't understand. I also learned that with Dashware and CVSViews that there are also ways to electronically monitor various items. I just have to learn how to read them. But, it's great. Thanks again. Wish me luck and happy flying to you all.

Thought I would chime in with my 2 cents worth...
You said earlier you didn't feel the same magnetic pull on one motor when you turned it by hand. Since the motors have permanent magnets that do not need electricity to energize, you would expect them to all feel very similar. They . That being the case, simply replace the one that feels different. You do realize the motors are only $18 retail.

As FlyNfrank said regarding soldering problems, just cut the wires and solder in the middle of the wire run instead of attempting soldering to the board. If the wires are twisted together before soldering they won't fail.

Just do it and tell us how it comes out. This is becoming too painful to read without you moving on to the ultimate fix.

 

[NRJ]

I don't know if it has been mentioned or not, but concerning motor noise, for some unknown reasons several pilots will land their aircraft in the grass, dirt, and other not so good areas. By doing that, it is rather easy for small debris to enter the motor and possibly cause issues. I have landed on a 3ftX3ft soft exercise mat only to help reduce any chance of taking on any debris.

I also want to mention that there was a pilot who felt he had noisy motors and he made a video showing where he applied a drop or two of lubricate into each of his motors. He had before and after sound test with in the video. I must say I'm not sure if I would do the mod, but it sure made his motors very quiet. I'm sure the thread and video are around here somewhere to where you could check it out.... It is worth viewing.

Hey flyNfrank, I remember that thread where the guy would test his motors by hand I think roughly once a week. He described how it did it. I think I will try blowing out the motors from the top too just in case there is some debree there too. Thanks.

 

[NRJ]

Thought I would chime in with my 2 cents worth...
You said earlier you didn't feel the same magnetic pull on one motor when you turned it by hand. Since the motors have permanent magnets that do not need electricity to energize, you would expect them to all feel very similar. They . That being the case, simply replace the one that feels different. You do realize the motors are only $18 retail.

As FlyNfrank said regarding soldering problems, just cut the wires and solder in the middle of the wire run instead of attempting soldering to the board. If the wires are twisted together before soldering they won't fail.

Just do it and tell us how it comes out. This is becoming too painful to read without you moving on to the ultimate fix.

I like flyNfrank's idea you mentioned about soldering the wires and not soldering the wires on the board. Seems like it won't be so tedious. I know some of you guys think I should get on with the fix, but, I don't mind taking my time to do it right, hopefully. I remember when I had a crash and attempted my own repairs on the gimbal. Bought a cheap ribbon cable and it didn't work, then paid more and got it working, but then it pointed to the left. I ended up getting a pretty good deal on the internet for a new camera. But, even that new camera pointed to the left. Sent to DJI and fortunately they covered it under warranty. So, I have learned that just jumping in and doing it without help and learning is not such a great idea and it took me a very long time to get it working again. So, now, I am learning tons from you guys with all your expertise and now I have a myriad of things to try. The ultimate decision is mine, but what a great source of information. My guess is that I will ultimately replace the noisy motor, and I will test it again once installed. But now I also have better ways to do it and also many processes to take into consideration when doing it. Thanks to all of you. You guys are great. Still waiting for my infrared thermometer to come in while I continue testing the motors with the stethoscope. I can still fly in the mean time, I'm just much more careful. I just don't fly too far.

 

[NRJ]

Aside, I keep the infrared thermometer next to the stove. Comes in handy for getting stuff like soup or meats up to 166 degrees, coffee below 149 (plus adding milk to cool it more), etc. Very handy kitchen appliance so it stays on the kitchen countertop.

Great idea's. There are a lot of uses, but I didn't think of those. Thanks.

 

[flyNfrank]

Hey flyNfrank, I remember that thread where the guy would test his motors by hand I think roughly once a week. He described how it did it. I think I will try blowing out the motors from the top too just in case there is some debree there too. Thanks.

Yeah that sounds like the same guy. I would like to add something about the motor situation overall. Try not to spend too much energy into the motors if they don't have a positive issue. The thing is, the Air Craft (a/c) is not built to last for ever. Even if you thought you were making headway in extending the life of the motors, there will be another electrical part on the A/C that is still going to fail at some point. One huge thing about DJI is...they really do want you to own and fly their next new model release.

 

[Dounin Front]

I continue testing the motors with the stethoscope. I can still fly in the mean time, I'm just much more careful. I just don't fly too far.

You probably do this anyway, but if not, hold the stethoscope against one of the actual motor screws below to get the truest motor sound.

 

[NRJ]

Yeah that sounds like the same guy. I would like to add something about the motor situation overall. Try not to spend too much energy into the motors if they don't have a positive issue. The thing is, the Air Craft (a/c) is not built to last for ever. Even if you thought you were making headway in extending the life of the motors, there will be another electrical part on the A/C that is still going to fail at some point. One huge thing about DJI is...they really do want you to own and fly their next new model release.

Point well taken. So far, I'm hanging in there with my P3A and not looking to get the P4 yet. Maybe by the P5 or P6. Haha. I wouldn't mind be like the Star Wars guy Hans Solo, who has a bucket of bolts that he fly's around in. We'll see how long it lasts. Thanks flyNfrank.