s800 is now solid as a rock

[Stevenhartman]

Hi Guys i just wanted to share. My s800 after tinkering like crazy in the workshop is now sitting rock solid in the air. I took all the stickers off the motors and checked if they were vibrating with a app on the iphone and managed to get rid of 99% of the vibration. all of them were off balance with those silly stickers on. there was one motor i balanced with a tiny piece of duct tape. props were re balanced. I moved my imu to the centre of the top plate and stuck that down with .3 cm thick 3m VHB. myh gps i moved to the centre of where the imu is supposed to be.

No funny shaking.

I am running 2 x 5500mah genz ace batteries. i have a home made gimbal and my sony NEX5 with video transmitter.

i got a 24 min flight with no blinking white lights no shaking and no wierd behavior. Gps lock solid and no problems. I will check again tomorrow but so far after three flights it seems very happy in the air

my gains are 180 180 185 180 100 100
imu -3 0 0
gps -6 0 -16

 

[SleepyC]

What app did you use to check for vibrations? That sounds very interesting!

 

[Bartman]

is there an app for android? does the iphone app work with an iPod Touch?

thanks,
bart

 

[Stevenhartman]

Hey guys it called mylseismo

 

[ChrisViperM]

is there an app for android? does the iphone app work with an iPod Touch?

thanks,
bart

Is there still some folks using iPhones....???? :highly_amused:

For Android you can use these Apps:

Seismograph: https://play.google.com/store/apps/details?id=com.atriuscreations.seismograph&hl=de x-y-z axis, can log data (but is a nightmare to weed through)
Accelogger: https://play.google.com/store/apps/details?id=jp.daikiko.Accelogger&hl=de x-y-z axis, can log data (but is a nightmare to weed through)
Max Vibrometer http://udm4.com/Android/Max_Vibrometer-617232 x-y-z axis, no logging

On all the apps you can see x-y-and z axis on their own graph which I like a lot. Apps which only show you THAT something is vibrating leave you with some guess-work on which axis the vibs are coming from....

Chris

 

[Stevenhartman]

lol i suppose spend all my cash on this hobby so i wont upgrade phones anytime soon.

BTW the 5.18 firmware and new software works very well. The delay on the M6 tune has be fixed and the also sorted out the take off which is now extremely smooth.

It also has a quick flashing blue light after takeoff that lets u know tha home position has been locked. the GPS also semms to hold position a lot better

 

[AustinFPV]

Can you describe the setup you used to test the motor vibration with your phone?

 

[Stevenhartman]

i took one arm at a time, took the prop off and used the app on the iphone. I put the phone against the base plate resting on the arm and spun the motor up to see how much vibration there is. i then peeled the sticker off and cleaned up the glue residue from the sticker. 90 % of the vibration was gone. i can get it better but for now its good

 

[ChrisViperM]

I just read your post again and went back to my S800....but no stickers on my motors, just some DJI stuff embossed/etched/encarved on the motor housing. Just wondering if there are different batches of motors out there.....I can imagine that DJI realized the vibration problem with putting stickers on their motors after the first production batch and changed later to encarving (looks like laser encarving).


Chris

 

[RadioFlyer]

It the etch has removed material the motor balance is EXTREMELY important
the sticker is better (after removed) as motor casing is ALMOST balanced to start with
posted last week
Great method for motor balance is the metal tape from Multiwiicopter.com
see link below.
I am surprised others had not done to the S800 motors at first sign of vibs.
You can balance to run like silk if u put time in

BTW, as it rained all day,,, I spent most of it BALANCING my S800 motors with little bits of sticky copper tape (weighty) from multiwiicopter.com
http://www.multiwiicopter.com/produc...e-5-pieceMotor balance tape and guess what..... the big bird is flying like a magic carpet. Almost no vibration at all. I have no idea why I did not do when I first built it.
Balanced the props but not the motors. But I am sure the wider the motor the more important the perfect weight around the casing is needed.
Like a magic carpet. I was considering carbon around the struts yesterday but no need now, however I still think putting the outer diameter in tension is a great idea.
Could also be done with a special build cable and 2 turnbuckle, with eyes on end of arms.
Another rainy day for this one.
RadioFlyer

PS balance motor needs to be done correctly.
a zip tie at first to find light points around body of motor then remove zip tie and add copper tape where head of zip tie was.
with multiwii I use config software to get feedback (realtime) on improvements.
with wookong S800 I used pitch only
better taking motor off arm to do.

 

[Stevenhartman]

Hi Chriss

I am not 100% sure. I got 3 units and they arrived the first week of Jan 2013. Every single one of them has the stickers on them.
All of them are using V4 esc's

I just read your post again and went back to my S800....but no stickers on my motors, just some DJI stuff embossed/etched/encarved on the motor housing. Just wondering if there are different batches of motors out there.....I can imagine that DJI realized the vibration problem with putting stickers on their motors after the first production batch and changed later to encarving (looks like laser encarving).


Chris

 

[Aviator]

I have had loads of problems with my S800 and have changed everything inside, i.e arms, IMU, GPS, FC, PMU the list goes on... The only thing that stopped most of the problems was plugging up all the holes in the top and sides of the center frame? I assumed because of the shape of the intakes it was creating a disturbance in air pressure within the frame and causing the machine to drop and rise a considerable amount by itself... Plugging these holes up solved 90% of the problems? strange I know... But putting the IMU on top would be the same effect as it removes the IMU from air pressure disturbance within the frame?

 

[ChrisViperM]

It the etch has removed material the motor balance is EXTREMELY important
the sticker is better (after removed) as motor casing is ALMOST balanced to start with
posted last week

That makes sense, I am just wondering about the stickers.....I only could find images on the net with motors without stickers:


View attachment 9342View attachment 9343View attachment 9344View attachment 9345




The only S800 motor I could find with a sticker was this one, but it doesn't look like an original motor :

View attachment 9346
http://www.fpvmodel.com/4114-motor-320kv-s800_p265.html


I just know the motors for the Flamwheel series got stickers.....very strange.


Chris

 

[Aviator]

I have only ever seen stickers on the S800 motors?

 

[RadioFlyer]

Mine have stickers on and arrived this Jan from dealer in Australia (MultiWiicopter.com) latest shipment to Quentin from DJI.
Sticker or not,
Remove if sticker ,just start balancing if etched.

put a small zip tie around motor and run without prop attached (of course),,,,,stoping and moving the big bit of zip tie around to different spots till u find the best balance,,, just like a wheel on a car, looking for where to put the weights.
You can hear the motor start to sing when it is in best spot.(u can use an aid like software on phone touching on arm, or software connected to controller if Multiwii or similar, but u can just hear it when it is good).
Then remove zip tie and use these motor balance tapes or similar.

http://www.multiwiicopter.com/products/brushless-multicopter-motor-balancing-tape-5-piece

(this metal tape works well as it has good mass for small size)
Then do next motor.
It can take more than one bit of tape at times for some motors to be perfect.
The best motors are dynamically balanced at build time.