Is it ok to recalibrate the IMU when it doesn't need to be? Reason why I ask is I want to cool the IMU down and recalibrate it so the Phantom will be ready to fly sooner rather than waiting several minutes for the IMU to warm up. I'm sure it's ok, but have ask to be on the safe side.

Done correctly, shouldn't hurt a thing.

WD9EON Posted at 2017-10-28 07:12
Done correctly, shouldn't hurt a thing.

Thanks, just had to make sure.

It is all right to calibrate IMU when it doesn't ask for. Please calibrate it in a horizontal surface.

Ask yourself, is it really worth that tiny bit of time you might gain vice risking getting a bad calibration or developing another problem due to conducting a calibration you really don't need?
If you can honestly answer yes then good luck to you...

Like Thor said, if you calibrate the IMU properly there is really no risk, and you are sooo correct about the startup time.  
I calibrated the IMU of my P4 initially after registering it, doing firmware updates, was a lot warmer then I thought, but I figured no big deal.  IMU calibration went fine.
After doing the cal......it would take a minute or more on initial startup to get a "green" good to go from the app.  Decided to try another calibration with the P4 cold (had a fan blowing on the P4 for 30 minutes) after reading a couple of forum posts about that very thing, and after that calibration it would take about 10 seconds or less to get the "Home Point" ready to fly signal.

After you do the IMU calibration just make sure you visually check the sensors in the Go app to make sure they are all in the green before your first couple of flights and you should be fine.  
I check those sensors before EVERY flight anyway...only happened twice when one was in the yellow, but still acceptable. Just restarted the Phantom checked to see the sensors were in the green and had a good flight.
Just make sure you check and recheck after the Cal and you should have no problems!

The level est spot I have to do IMU calibration is my kitchen counter. Does metal under counter affect the calibration? i.e. the dishwasher and silverware.
Thanks

I agree with Genghis9. If it ain't broke, don't fix it. You should get a warning if it's needed. It is sort of like cleaning a sensor. Does it hurt to do it? Not if done right. Can you actually make the sensor dirtier if you don't do it right and let more dust in? Absolutely.

If you try and calibrate the IMU on the kitchen counter, the sink and pipes will give you an error message, about the compass.

If you sat it on the kitchen/dining room table, would be much better. Even a side table in the living room.

A cold IMU calibration followed by a gimbal calibration, has also helped many retain an appropriately level horizon.


RedHotPoker

Genghis9 Posted at 2017-10-29 03:38
Ask yourself, is it really worth that tiny bit of time you might gain vice risking getting a bad calibration or developing another problem due to conducting a calibration you really don't need?
If you can honestly answer yes then good luck to you...

It's pretty difficult to do a bad IMU calibration. You might be thinking about others who have had a bad compass calibration though. Some who feel it's important to calibrate thier compass before each flying experience risk that happening those drones/pilots.


RedHotPoker

RedHotPoker Posted at 2017-10-29 18:03
It's pretty difficult to do a bad IMU calibration. You might be thinking about others who have had a bad compass calibration though. Some who feel it's important to calibrate thier compass before each flying experience risk that happening those drones/pilots.

Maybe so, but what if they don't take care in ensuring a level surface...any time you attempt a calibration you are going to introduce error albeit a successful one is within the tolerances allowed.
The issue is what if, what if you don't or you end up with more error than you had.  When it comes to things like this you are best to leave well enough alone if it ain't broke don't fix it.

Quite recently I had updated my drone, with the latest and greatest Go app, so an IMU and gimbal calibration were done.
Still I haven't, but will want to calibrate the compass..


RedHotPoker

Genghis9 Posted at 2017-10-29 18:06
Maybe so, but what if they don't take care in ensuring a level surface...any time you attempt a calibration you are going to introduce error albeit a successful one is within the tolerances allowed.
The issue is what if, what if you don't or you end up with more error than you had.  When it comes to things like this you are best to leave well enough alone if it ain't broke don't fix it.

I have to agree with Red Hot.....plus Jake is saying that effectively he did NOT do the initial calibration properly.....because if it is taking "several minutes" after startup for his P4 to be flight ready, something is wrong.  
It should not take a that amount of time for a P4 to be ready to fly........he probably did not do a proper cold IMU calibration.