Elev-8 v2 vibration

Mysticmindset

I am having a vibration issue with from what I can see is 3 out of the 4 props on my elev-8. If I look at the threaded part that screws to the motor at the top is a tiny nub from machining that doesn't seem to run true. I cleaned up the service of the motor and also re machined the surface of the aluminum part that touches the motor with out any improvement. I am looking into balancing the props but I'm sure if the threaded part that holds it isn't true the balance will not help. I also have a noise in one or all motors under half throttle.

Ken Gracey

Mysticmindset,

Welcome to the forums! We'll get your ELEV-8 V2 into the air without too much work. This product must be built precisely according to instructions in order to fly.

It sounds like the propeller adapter on the top of your motors is out of true - is that right? It would be the first time I've seen this, but it's certainly possible. I have a couple of things you need to check and verify:

- Spacer rings for propellers. The propellers will not center on the motor's propeller adapter unless you use the correct black plastic spacer ring. Can you verify that you installed the ring?
- Motor mount screws to standoffs. If one screw is missing on the motor mount then you'll experience vibration. They need to be firmly installed with the lock washers. Are they fully assembled?
- Propeller balancing. I've never done it and haven't experienced any visible problems from not balancing propellers.
- Motor screws to motor mount. Is each motor attached with the 3mm x 6mm screws?

I have to ask these questions because I've seen these built a variety of ways, often not according to instructions. Cold solder joints in the motor wires are usually the biggest problem.

We can knock these issues out one at a time and get you in the air.

Thanks,

Ken Gracey

Mysticmindset

Ken

Thank you for your quick reply and help. Here is a picture of my build that I hope will answer some or all of your questions. I completely understand your "from the ground up" questions about my build and should have asked the same things. If I have time tonight I will ohm out all of the connection wires.

Ken Gracey

The propeller adapter seems properly seated on the motor, perhaps because you cleaned it up.

Now that it's right, is the vibration reduced?

Mysticmindset

I did not see an improvement. The vibration was there during the first flight. I then took the adapter off, lightly scraped and cleaned off the top of the motor and used a concrete floor to lightly clean up the motor side of the adapter. It seemed like then it was only one motor and adapter without prop that ran true. I then used a lathe with it lightly chucked on the thread side with the flat that the prop sits on against the chuck and took a small amount of material off the motor side an all four adapters. I then deburred all edges that I machined and lightly sanded the motor side to make sure there weren't any high spots or chips from machining and I still get the vibration.

Mysticmindset

I'm running a futaba j6t and a 2100 mah batt. Have not gotten a chance to pick up the 3300 mah I think that is speced but don't think that has much to do with it. Also I could not get out the motor set screw with supplied Allen wrench so I felt as though it was worth messing with just to lock tight it.

Mysticmindset

I have a video I took the other day of a clicking sound I beleive at least one of the motors is making. I took it out for a little flight and nothing has changed since first flight. It seems to make an oscillating sound at a frequency of about a second. As I watch it fly at least one motor combo is making it shake visibly about ten feet off the ground and 20 feet away from it. I have been thinking about how to figure out what motor or motors is making this problem and my solution is going to be to take each motor and put it on a rubber yeast stand with a laser pointer to visualize the vibration.

Publison

Mysticmindset wrote: »

I did not see an improvement. The vibration was there during the first flight. I then took the adapter off, lightly scraped and cleaned off the top of the motor and used a concrete floor to lightly clean up the motor side of the adapter. It seemed like then it was only one motor and adapter without prop that ran true. I then used a lathe with it lightly chucked on the thread side with the flat that the prop sits on against the chuck and took a small amount of material off the motor side an all four adapters. I then deburred all edges that I machined and lightly sanded the motor side to make sure there weren't any high spots or chips from machining and I still get the vibration.

You really should not have to go through all this. They should work out of the box. The components Parallax supplies are of good quality.

Could you tether the Quad to a good surface ans run it up in a static mode? If you have a vibration, you should be able to see on of the booms oscillating.

If you could post the video, that would be great also.

Mysticmindset

http://www.youtube.com/watch?v=2tWUXlvPvQo

This is a YouTube video of the clicking sound I am hearing

Publison

Sound almost like a bearing problem, but its hard to tell which one it's coming from. You can usually use a screwdriver as a stethoscope and place the pointed end on the motor mount and press the handle on your ear.

BTW, don't run the motors too long without the props. They need the props for cooling.

Mysticmindset

http://youtu.be/PZvBKyi2DLc

Here is a YouTube video of most likely what my clicking sound is. I'm going to pull apart my motors and check it out this week.

Publison

Mysticmindset wrote: »

http://youtu.be/PZvBKyi2DLc

Here is a YouTube video of most likely what my clicking sound is. I'm going to pull apart my motors and check it out this week.

Interesting video. Looks like a QC issue. I'm sure Ken would like to know about this. My four motors seem fine, but they may have been from a different lot.

Not to worry, Parallax will make it good, they always do, they are the best in customer satisfaction.

Publison

BTW,

Welcome to the Forums!

Mysticmindset

Thank you I'm glad to be a part of it.
I bought this product because of the ability to add on to it and use it as a platform to learn more about this technology. Half of the fun of electronics and such is tuning and tinkering for me.
I'm not going to place a name here but at the same time as I purchased the elev-8 I bought a ready to fly quad copter with other features totaling 1700 dollars including some extra props.
I will have some time tomorrow to experiment with what is going on with my elev-8 and greatly appreciate the help guys.

Mysticmindset

I never even thought about the trick with the screw driver. I have used that many times before.
I just want to make a quick comment about my background.
I am 28 years old. I took three years of vocational machine shop with much focus on automated machining. I am currently in the automotive industry as a sevice equipment technician. I install and repair car tire balancers computer controlled tire changers and computer operated optical wheel alignment machines that use camera technology to take pictures of reflective targets that get mounted on your cars wheel to calculate the alignment angles in reference to the manufacture spec.
My dream job would be to develop and test electro-mechanical machine that other people can use to solv a problem they face.

Ken Gracey

Let me know which parts I can send you to fix the problems you're having.

We don't test the motors and ESCs, so it's possible they could have problems. I'm happy to replace everything you need.

kgracey@parallax.com.

Sorry for the troubles!

Ken Gracey

Mysticmindset

Hey ken,
I just started to pull apart my copter and found one motor has a winding sticking up like the one video I posted and I fixed it the same way the guy depicted.
One other observation is on the clip side of 2 out of the four motors were two metal washers then one plastic one followed by the clip. On the other two mothers were four plastic washers.
I put a meter to the motor and got .1 to .2 ohms between the three wires. The connecting wires also came in low at from .2 to .3 ohm.

Mysticmindset

To everyone following I have done some tests and found some sub par motors. This has been my first experience with a parallax product and all I can say is that it has been an enjoyable time so far. They have worked closely with me especially Ken Gracey with regard to fixing the issue.

Publison

I'm guessing you have the blue motors on the Version 2, correct? I will be doing some flights on Sunday with the same motors, (now that the snow is gone).

Ken Gracey

Mysticmindset had some motors with excessive runout. He put a dial indicator on it and found 0.01" runout on the top of the case where the prop adapter attaches.

These motors are from China and we recently received a box of them which experienced some sort of excessive force during shipment, like they crossed the ocean in a john boat with a 10 hp motor. We sorted through them and discarded damaged motors, but it's possible a few made it out in our kits.

Our Purchasing Manager has contacted the supplier (KEDA Model) and filed a QA/QC request. They've replied by telling us they can do a "dynamic balance" for the motors. I'm not sure what this means but we'll find out, visiting them as necessary to get this straight.

If any customers have ELEV-8 problems please do not hesitate to post them here or contact us. We'll replace any parts you need. When our new Flight Controller comes out it'll be easier to diagnose some of these problems.

And Mysticmindset, thank you for the suggestion that I be promoted. I don't want any more responsibility at Parallax.

Ken Gracey

Mysticmindset

Ok here is an update. I have replaced all for motors without changing anything else about it, even the props are the same. After a test flight and inspection the motors seem to run true with no noticeable runout. I still notice what prompted my invesigation in the first place. Turn up your volume and check out these two videos.

https://youtu.be/K1QpkzGxr6E

http://youtu.be/pDwpgP8P1j8

Publison

Are you still experiencing "clicking" I thought i heard it in Video #2"

Mysticmindset

Yup I found one of my original motors to have a coil protruding. These are brand new

Mysticmindset

The "clicking" was there at the beginning of my test flight. Then I moved to the garage with it weighted and recorded that. I'm not positive that I noticed the clicking as bad as at first. Then I went outside again to film as my battery was beginning to have a noticeable amount of discharge. The main point of the outside video was to show the sound it makes in general during flight and not heard in the static video. I have one question could this be poor vibration dampening to the flight controller. I have the same amount of threats showing as in the build instructions.

Publison

Mysticmindset wrote: »

I have one question could this be poor vibration dampening to the flight controller. I have the same amount of threats showing as in the build instructions.

Not sure what you mean by "same amount of threats showing". When using the isolation mounts, (blue), on the controller board, you should gently snug the nylock nut down ensuring there is still enough play for the board to "float".

Mysticmindset

I meant to say threads. This is from the build instructions. The amount of threads protruding from the bolt match my build.

Mysticmindset

After watching some videos on youtube I came across one that displays the same sound/vibration that is coming from mine.
https://youtu.be/DknL1HpIGZs

xanadu

Okay rule #1, when your copter isn't feeling well don't hover it 10' above pavement and ice haha.

What happens with the new motors if you run them up on the ground?

Mysticmindset

When I held down my copter with weight the noise isn't there. I took it out today and held the flight controller mount as ran up the motors with props attached( I wasn't happy about being that close to 4 spinning props) it seems as though when it tries to correct itself that the motor that isn't in need of power flutters. I'm going to look into this more but when I first built the copter I updated the firmware. Today I again updated firmware. The issue I'm having does not seem to directly effect how it seems to fly. I still have full control. My main concern is that it can be better. I have watch many videos of quad copters and do not notice this happens inc with them or the other quad copter I own. I do not think of this as an error in how parallax designed it. I gain enjoyment and knowledge about what is going on. I do the same at work, if equipment isn't functioning right it is my job to figure it out. Then in the future I can take a look at it and say hey I have experience that and have you tried this to fix it. I really like the uav parallax has built and look forward to using other products of theirs for my hobbie. I apologize if I have gone on for too long with this I have been awake for close to 20 hours. I just wanted it to be clear of how I feel about the journey I am on.

Ken Gracey

If you hold an ELEV-8 to the ground and increase throttle to full then you'll have problems that wouldn't occur if you were flying. Imbalanced propellers could vibrate, motor mounts might vibrate and any imperfection in assembly will show through, It could be comparable to holding your car breaks while giving full throttle at the same time.

Some design changes would enable a vibration-free full throttle, too.

Ken Gracey

Mysticmindset

When I was younger I would take my car out to show off in front of my friends. I would hold the brake down and push the throttle at the same time. An imbalance that is designed into all passenger cars would cause the front two tires to hold and the back two to start to spin. It was a ton of fun until I had to buy new tires. �� Yesterday I held the copter off the ground with my hand and only advanced the throttle until the props we're spinning. The motors weren't even at a speed which would lift the copter off the ground. I then put in some force as if the copter was not balanced and it seemed like the motor that was not needed to supply the speed to correct for the imbabace would flutter.