(01-Aug-2017, 05:19 PM)Spokanesteve Wrote: Watch flying on wet grass!

I was flying with my son this am on wet grass.  After a couple landings/crashes in the grass the motors didn't seem to be arming correctly.  I walked over and I was trying to diagnose the problem when at least a couple motors did arm and the quad leapt up in my direction.  I have three good cut areas on my arm and bruise on my chest.

My theory is that the wet grass clippings and moisture caused the malfunction.  I got home, removed the props and it seems to be running fine again now that it's dried out

Ouch! that looks painful.

Admittedly I fly on wet grass probably more than I should. Unfortunately being in Georgia if I didn't I'd rarely have anywhere decent to fly.

I think you have convinced me to put something out to take off and land from.

My buddy has a heli pad thing that he puts out and while it's too small for landing it's a cool little thing. I might make something similar to it out of an old sheet or something. Perhaps 4x4 ft with stakes to drive it in at the ends.

(01-Aug-2017, 05:19 PM)Spokanesteve Wrote: I was flying with my son this am on wet grass.  After a couple landings/crashes in the grass the motors didn't seem to be arming correctly.  I walked over and I was trying to diagnose the problem when at least a couple motors did arm and the quad leapt up in my direction.  I have three good cut areas on my arm and bruise on my chest.

Well done for posting this so that others may learn from your mistake.

Don't forget that it's your flight controller that arms, not your motors, so if your flight controller is armed, it will be trying to spin the motors (unless you have the MOTOR_STOP feature enabled).

An armed quad with propellers is inherently dangerous and any fault finding, even at the field, should be done with the props removed!

When I first got into betaflight I was getting recommendations everywhere for the default motor speed to be set at a small percentage when armed with no throttle, that way i wouldn't even be tempted to touch the quad if it were armed since the props would be spinning at just under threatening speed in its stationary position, and I'd have no choice but to hit the arm switch before grabbing it. Saves a lot of potential mishaps.

Since I use air mode by default, once armed the props spin in very much threatening speed already, so no touchy-touchy.
Also what I built as a habit (okay, 95% of the time I do that) is that when the battery is plugged in but the quad is not armed, I put the throttle to middle, or pretty much anywhere above zero, so that even if I flick the arm switch unintentionally, it won't arm. Another - and recommended - option is to set up a dual switch arming.

(06-Nov-2018, 01:41 PM)izzy26 Wrote: I put the throttle to middle, or pretty much anywhere above zero, so that even if I flick the arm switch unintentionally, it won't arm. Another - and recommended - option is to set up a dual switch arming.

I do exactly the same, as recommended by JB in a number of his videos. As long as you do this I think a secondary arming switch is probably a bit of an overkill and an unnecessary hassle.