"Bubbles" on Gyro log

[phynix]

Hello,

I get consistantly something that looks a little bit like bubbles on the log of the y-gyro. It is always only on the y-rate and at roughly the same temperature. I tried three boxes with different foam at different lokations. Someone knows what could be the reason for that?

Sören

[JussiH]

Pls post a screenshot of voltage 0,1 and 2 from the above log. Thanks!

[phynix]

This is not the same Plot, but it shows the same problem. Unfortionally, I accidently deleted the log from the picture I posted above. Here is A plot of the voltages and of the rates

[JussiH]

Well, most likely it is condensation on the board. The gyros are working normally from what I can see.

Depending on what kind of insulation you use for the box, it can suck up quite a lot of moisture from the air.

Try and dry out the box, insulation and board before putting them in the freezer. This time of year, it is easy to get condensation.

When I get this problem, I place mine on my woodfired stove and let it dry out at 60C for an hour or two before freezing it. Do not go above 80 degrees!!! If your kitchen-oven can do low temp, it might be a good candidate. Otherwise, just place the open box on a radiator or similar and let it dry out there.

When you place the box into the freezer, you can just leave the lid open but set at an angle. This will allow the contents to come down in temp, but protect from moisture getting inside. Look at attached photos.

Leave the top insulation in place:

And put the lid on a angle before placing it into freezer:

[phynix]

Thanks for your help! I will try the drying before freezing tonight and post the results.

Im just a little bit curious as it happens always at amlost the same temperatures, with a similar shape and only on the y-gyro. I also tried putting a lot of silica gel (from our laboratory) inside the box, but with the same result. But I havent heated the box before freezing yet, so I will give it try!

[JussiH]

There is of course an odd chance that your particular gyro could have a problem, and then it would need to be replaced - which will be done under warranty!

As a control, you can just leave the board at room temp for an hour while logging and see if the problem persists.

At what temperature does this happen?

[phynix]

One "Bubble" always appears arround 52°C. So, for my first calibrations I just trimmed them away. The "clean" range that I could use was then from about -14 °C to 50 °C, I hope that is sufficient. But I wanted to figure out what is the reason in parallel.

I have another odd problem: As already menrioned the Quad was rolling constatantly to one side (in manual mode) until I wasn't able to counteract anymore because of the limits of the RC. So, I watched some values in the live-telemetry with removed probs. When I arm the Quad and then increase the throttle a little bit, the values for pich and roll start to drift away from the flat line that was there before (while the quad is not moving!). This somehow matches to its behaviour while flying.

This seems to be worse shortly after powering on the unit, and seems to be almost gone when it gets some gps signal (I am not sure about that).


What can I do to determine the reason for that / solve that issue? Shall I open an extra thread about it?

[JussiH]

Well, Bill jumped in and told me that the bubble is likely a gyro malfunction but that it also may not be problem for calibration because of the symmetrical nature of the distortion.

But based on that I will offer you a gyro or board replacement under warranty, but you will have to send this board back here. Drop me an email, and we will work something out and make it a fast turnaround.

[phynix]

Alright, I have just finished a log with silica gel inside the previously dryed box (as suggested). Unfortunately again bubbles on the y-gyro at the same temperatures.

@Jussi: I send you an email.

[Jdmagoo]

I think i may have the same problem but not sure, please see attached, is this going to be a problem?

.

James

EDIT: just tried a run without the foam and there was only minor noise on the graphs, so I tried Jussi recommendation above of placing the foam, board and container in the oven, I could only have it at 40 degrees Celsius as the next level was 100 and had it cook for 3 hours. Unfortuantley this didn't work as I had noise again on the graphs. What sort of foam are people using? I'm thinking of having a smaller container and insulating it on the outside with foam, would this suffice?