IMU Calibration

Explorocam

Explorocam

Airborne Media Pros
I had it taken care of. I sent it back to Heli FLight store and I got a new board. Works great now prob. I'm using 4s and it's stable regardless of the voltage.

Basically DJI helped as much as they could and Heli flight Store agreed to send the board as soon as the old ong got to them. I sent the board in on Monday and got the new board on the Thursday. I've put a few very cold flights in and some flight just a little over 0 degrees and it fly great, I didn't even have to mess with the IMU calibration.

@w4arf,
If I were you, I'd put a multimeter on all the wires, sounds like is something wrong with wireing, or one of the ESCs or possibly one of the motors. I think if it was an IMU thing you would see the drift regardless of the voltage. But if there is some kind of drain on one of the motors or ESCs you would get what you are describing. Have checked for any vibs coming from the motors?
 

W

w4arf

New Member
Explorocam

The problem has been across two birds with all new components .....It must be some thing in the Naza that is voltage sensitive. I don't use BEC's as the VU supplies the voltage. The voltage out of the VU will change slightly as the battery discharges. I eturned the VU GPS and Naza....They are just replacing the Naza.
 

Explorocam

Explorocam

Airborne Media Pros
OK,

Wow, that's a strange one. If you are using a gimble than I'd use a Bec. I have a bec supplying power to my roll and pitch servos.
Well, I hope the new Naza fixes your prob, but if you had the same prob on two different machines than it must be the Naza, or maybe the GPS.
I sure you adjusted the GPS for the CG, I forget what that panel is called but I'm sure you know what I mean.
 

J

JG-rn

Member
Question,

shoud the imu be calibrated on a brand new never flown naza, or wait to see if there is drifting issues?
 

Explorocam

Explorocam

Airborne Media Pros
JG-rn said:
Question,

shoud the imu be calibrated on a brand new never flown naza, or wait to see if there is drifting issues?
Click to expand...

It's really up to you.
It should fly just fine if the board is working properly. However, if you are going to mount the board on a non-horizontal surface then yes you will need to calibrate the IMU. But if you are mounting it on a Horizontal surface than give it a try. If it drifts, Calibrate it. If not, don't worry about it. My first one drifted like crazy and calibration didn't help, I got a new board from my retailer and it worked right out of the box so I didn't even mess with calibrating the IMU.
 

T

Ttelmah

Member
I see lots of people talking about calibrating the IMU, but nobody has mentioned to study the radio calibration.
Your radio must be setup so that when you release the sticks, the sliders go into the 'green' bit in the calibration screen, or there will be drift. On my radio I found that even though the stick is spring loaded to centre, if I calibrated the endpoints, it'd still miss the green spot as often as hit it. I just altered the stick curves fractionally to flatten the bit in the centre of the aileron, rudder and elevator responses, till I could get a 100% 'release sticks and the bars are green'. Got rid of the drift problems....
Basically the sticks were a fraction too sensitive in the centre, and not reliably hitting this spot.

Best Wishes
 

Explorocam

Explorocam

Airborne Media Pros
Ttelmah said:
I see lots of people talking about calibrating the IMU, but nobody has mentioned to study the radio calibration.
Your radio must be setup so that when you release the sticks, the sliders go into the 'green' bit in the calibration screen, or there will be drift. On my radio I found that even though the stick is spring loaded to centre, if I calibrated the endpoints, it'd still miss the green spot as often as hit it. I just altered the stick curves fractionally to flatten the bit in the centre of the aileron, rudder and elevator responses, till I could get a 100% 'release sticks and the bars are green'. Got rid of the drift problems....
Basically the sticks were a fraction too sensitive in the centre, and not reliably hitting this spot.



Best Wishes
Click to expand...

I did this with my unit and it still didn't work with IMU calibration. Mine was so bad that I could tilt the Hex by 45 degrees and the drift didn't change at all, my calibration didn't even respond to any kind of movement the calibration didn't even work period. I think what you've mentioned is very important though, I'm glad you brought it up, could be something new to multirotors might miss.
 

kloner

kloner

Aerial DP
the couple times i've seen that the radio just needed to be rebound.....

Ttelmah said:
I see lots of people talking about calibrating the IMU, but nobody has mentioned to study the radio calibration.
Your radio must be setup so that when you release the sticks, the sliders go into the 'green' bit in the calibration screen, or there will be drift. On my radio I found that even though the stick is spring loaded to centre, if I calibrated the endpoints, it'd still miss the green spot as often as hit it. I just altered the stick curves fractionally to flatten the bit in the centre of the aileron, rudder and elevator responses, till I could get a 100% 'release sticks and the bars are green'. Got rid of the drift problems....
Basically the sticks were a fraction too sensitive in the centre, and not reliably hitting this spot.

Best Wishes
Click to expand...
 

T

tugboat

Member
w4arf,
I had the EXACT same issue as you did, CG was on the spot for the naza and I tried everything to straighten it out. (motors, esc's, re-cali's no cali's....everything)
On launch from a level surface with a fully charged 4s batt it would jag right and a bit ahead, so I'd add trim till finally it would do a perfect vertical take off.... then I'd have to take the trim out because it would start to go to the left in hover (whole time in atti. mode) then I'd look at the trims and the 2 I had been adjusting were only 1-2 clicks off center.
Well this went on for some time trying to find the issue, and here is the end result...
I only caught this happening twice on the naza asst. screen(got screen shots to prove it), the quad was going in the direction of the slider bars in the Tx cali. screen which were not green anymore (centered) and there was a magic time period about 2 minutes where it seemed the quad had to warm up and then it was fine with the previous days settings and would launch perfectly straight up!!
So this was what I did, I bound my Tx to my little blade mqx quad set the trims for perfect hover and left it over night... the next day I flew the mqx and all was perfect no issues.. tried the disco and same issue but only for the 2 minutes then all was fine and I had made no trim adjustments. ( this ruled out the Tx)
And here is the real wacky part, if I ran 2-3 paks one after the other then no issues but if I shut down for at least an hour it would be right back to square one.
On the bench with the props off I would start the motors and leave them at a low rpm, well there was a noticeable difference in rpm's between the right front and the other three (visually and audibly) UNTIL the magic 2 minute window started to pass, then that motor would pick up speed until it synced with the other three...then all was fine!!!
So in the end it was determined that the naza was having issue's.... My Canadian dealer backed me 110% and was very helpful!!! they sent out a new fc to me immediately and I sent the other back to them....
So you might ask who is this dealer...... BRADATECH in Ottawa,Ontario Canada.... same town as Explorocam lives in.... check them out.

One other interesting thing.. the VU would mostly flicker when hooked to the asst. not flash, not blink, but flicker green.... rarely was it a steady green, they are replacing that as well.
tugboat..
 
Last edited by a moderator:

Explorocam

Explorocam

Airborne Media Pros
tugboat said:
w4arf,
I had the EXACT same issue as you did, CG was on the spot for the naza and I tried everything to straighten it out. (motors, esc's, re-cali's no cali's....everything)
On launch from a level surface with a fully charged 4s batt it would jag right and a bit ahead, so I'd add trim till finally it would do a perfect vertical take off.... then I'd have to take the trim out because it would start to go to the left in hover (whole time in atti. mode) then I'd look at the trims and the 2 I had been adjusting were only 1-2 clicks off center.
Well this went on for some time trying to find the issue, and here is the end result...
I only caught this happening twice on the naza asst. screen(got screen shots to prove it), the quad was going in the direction of the slider bars in the Tx cali. screen which were not green anymore (centered) and there was a magic time period about 2 minutes where it seemed the quad had to warm up and then it was fine with the previous days settings and would launch perfectly straight up!!
So this was what I did, I bound my Tx to my little blade mqx quad set the trims for perfect hover and left it over night... the next day I flew the mqx and all was perfect no issues.. tried the disco and same issue but only for the 2 minutes then all was fine and I had made no trim adjustments. ( this ruled out the Tx)
And here is the real wacky part, if I ran 2-3 paks one after the other then no issues but if I shut down for at least an hour it would be right back to square one.
On the bench with the props off I would start the motors and leave them at a low rpm, well there was a noticeable difference in rpm's between the right front and the other three (visually and audibly) UNTIL the magic 2 minute window started to pass, then that motor would pick up speed until it synced with the other three...then all was fine!!!
So in the end it was determined that the naza was having issue's.... My Canadian dealer backed me 110% and was very helpful!!! they sent out a new fc to me immediately and I sent the other back to them....
So you might ask who is this dealer...... BRADATECH in Ottawa,Ontario Canada.... same town as Explorocam lives in.... check them out.

One other interesting thing.. the VU would mostly flicker when hooked to the asst. not flash, not blink, but flicker green.... rarely was it a steady green, they are replacing that as well.
tugboat..
Click to expand...


Who's your dealer in Canada?
My dealer was not as helpful. It was like pulling teeth until DJI stepped in and I had to send the unit back first. Kept going on about being burned in the past. Please tell me who your dealer is.

Will.
 



T

tugboat

Member
No but I'm close.... Superior,Wisconsin.... yeah I'm a cheese head...
Been to your country many times and even did the circle tour around Lake Superior, Canada is BEAUTIFUL and met lots of Canadian's all great folks!
I stumbled across Bradatech a while back while I was still looking to purchase a quad kit, so I emailed them and had a answer within a couple of hours!!
I emailed again.... same response time!
I have even called him (Yves) twice... he answer's the phone!!
I have not found any better customer service anywhere!!
I tried contacting supplier's and such in the states and found that... 1. They dont answer the phone or if I leave a message no return call will come. 2. Email if it is answered is very very slow (2 plus days... if at all).
He has a great help forum and has a tech (Mitch) who is very sharp!!!
It does take about 7 days to receive things in the mail but this is due to international shipments passing thru customs and not due to the company.
I ordered parts from Bradatech and within minutes ordered parts from a company in California, both shipped priority mail and guess what.... both packages arrived at my house on the same day by the same US mail carrier.
The parts I ordered from California did not even move from the shipper for 2 days, Yves (Bradatech) had his in the mail within hours!!!!
I will accept the long transit time from Canada in exchange for business integrity and customer service...
Mark
 

Explorocam

Explorocam

Airborne Media Pros
Great to hear.
Well if you are ever interested in coming up to the Eastern Ontario area to do some filming contact me and maybe we can put something together. I have some good ideas.
 

R

rdalemercer

Member
Explorocam said:
Ok, here's the first video of how I calibrated the IMU.


I cut the video a little short but I finished by unplugging the batter, turning off the transmitter and then unplugging the USB.

Not sure if I missed something.


Here is the second video of my setting up for IMU calibration. In this one I slide a thin piece of cardboard under the right side of the hex and check for to see if the gyro degrees change a little.
Click to expand...

Hi Exploracam - When I click on your video it reads "This video is private". Is there a way that I can see them? A

s noted in a different thread, I am having a slow yaw to the left (-Y) that will not stop even with trim added. I have just found out about the IMU calibration and completed it - but have not flown as it is raining here right now.

Thanks.
Dale.
 
Last edited by a moderator:

Explorocam

Explorocam

Airborne Media Pros
rdalemercer said:
Hi Exploracam - When I click on your video it reads "This video is private". Is there a way that I can see them? A

s noted in a different thread, I am having a slow yaw to the left (-Y) that will not stop even with trim added. I have just found out about the IMU calibration and completed it - but have not flown as it is raining here right now.

Thanks.
Dale.
Click to expand...

Oh sorry about that.

I made them private after the problem was resolved. I made them private as I didn't want potential clients finding videos that could be construed as problematic. I can let you view them if I have your email.
 





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