Tricopter arms folding midflight

I built David's Tricopter, didn't follow any specific version. I was flying with the KK2 v1.6. It was flying pretty well and I was doing figures of eight. Now, at one left turn, I noticed that it'd turned into a T-copter!! It was still flying stable though. After a few more seconds of flying forward, the arms folded completely and it fell out. Now, I wasn't using lock nuts, and the main purpose of the flight to test if it was flying at all. But I got carried away a bit!
I want to know how exactly to ensure the arms don't fold in midair. I've got a set of new motors and esc's that I want to put on, but before that, I want to ensure that the arms wont fold up so easily.
 

Liemavick

Member
Mentor
It sounds like your body wasn't fastened snug enough. The arms should be able to fold, but with some effort to do so. Not fold easy with no resistance. Lock nuts are your friend! The vibration will work loose regular nuts with no loctite on them according to David :)
 
Alright, thanks! I'll do it once I get hold of some. So, the arms are basically held in place by friction alone? Would putting a small bit of fiberglass just behind the arm help? I was also thinking of using velcro straps at the arm root. Would it make any difference?