"Anything that stresses the material destroys it's properties. Hence most types of cutting, and bending. After forming, you have to heat treat it in a hydrogen atmosphere...
Alternatives are to use very thin foils, and be careful, with only gentle…"

"You do understand, that when you cut or bend mumetal, it has to be annealed again to restore it's properties....

Best Wishes"

"If you have a bit of time, wait and see what 2.9.2 gives.
There are bits of 2.9.1b, that are better than 2.8.1, but currently it has some significant problems is any 'energetic' movements are undertaken by either the pilot, or the auto-pilot. Use a…"

"If you search the forum, the 'somewhere else' behaviour is well reported...
Apparently there were some significant changes to the handling of the Mediatek GPS with 2.9.1, and it results in spurious readings being accepted. The explanation being…"

"The smallest I could get to even get close to working in this size, was a 9*5" 5 blade prop, which running on Alle KDE500XF-1450 motors, can give enough thrust to hover at about 76% power. However you are then talking about 80amp per motor at hover…"

"Why did you replace the arms/motors?
If it was because of a 'prang', then start by triple checking the new stuff is square. Then have you recalibrated the IMU?. The rotational control is nothing to do with the GPS. It is compass, and IMU. Does it…"

"You need to tell us more. Weight of model in particular. But if (for instance), this is about 2.2Kg, reducing your props to 9*5, or 10*3.7, would bring everything inside reasonable limits.
Try some experiments with ecalc, feeding in your current…"

"Hm.
Unlike most of the obvious ones, where a motor/prop/ESC fails, yours kept straight, and recovered (ruling out most electrical problems).
Obvious first one, would be a radio control RX set to 'fail' to sticks central with low throttle. That would…"

"The baro hold is very good in the new software 2.91/9.1b.
It will drift slowly with time, but typically no more than a foot in an entire flight time.
Where sonar wins massively, is doing low altitude terrain following.
Sonar gives faster altitude…"

"Is this on the ground?. If so', there was a thread about this in 2.9.1, and a fix given (it was one parameter that needed changing). It didn't affect flight, and I'd suspect the fix has been included in the quad settings.
A search on the forum for…"

"On the current release, is is:

logs<enter>
enable CUR<enter>

I had it enabled in the bitmask fr my configuration, so hadn't had to turn it on from the command line. At some time in the past, it was 'CURRENT', but it now only wants CUR (though it…"

"You can specify what is going to be logged in the onboard memory.
From the cli log menu - where you download the logs, type 'enable current<ent>'. This turns on logging to the onboard memory, the data from the current sensor (including voltage).…"

"The knob should have a resolution of hundreds of points.
You need to step through every stage in the process.
First at your radio. How is the pot configured, what range of output does it generate?.
Then use the radio calibration screen, and look at…"

"Have you looked at:
<https://github.com/diydrones/ardupilot/pull/125>

This was a guy working on code for the I2C sonar, and I'd ask him how he was getting on.

Best Wishes"

"The log 'wraps'. Starts overwriting itself from the beginning.
Now all EEPROM/Flash memories have a limited erase/write life. So the more often you write data the faster they will fail. On EEPROM quite low (typically something like 10K cycles).…"

"Only thing is (of course) that less vibration reduces the risk of failures in electronics in general.
However unlike the IMU, where the acceleration sensors get somewhat swamped by vibration, so good damping improves behaviour, something like a thin…"