ORIGINAL: MinnFlyer
I realize that, and I'm not trying to be a smart *****,
But you're doing such an excellent job of it.
I'm just saying that if the mount had failed while doing what it is designed to do (IE, Fly the plane) I'd say, "Ok, it was too weak to do it's job". But you weren't there to see what weird thing it may have done as it hit. Whatever it was, the firewall was not designed to stand up to that.
I'm not the least bit convinced that it did not fail while flying. From my autopsy, it looks to me like the liteply was breaking down. And the airplane hadn't even had a single hard landing. But know of no way to prove or disprove either way. BTW, the veneer layer had been imprinted by the lettering on the back of the motor mount. It wasn't strong enough to stand that. And the veneer was obviously impressed by the edge of the mount all around.
It WAS designed to pull the airplane, and to be as light as possible as it does so. It did it's job until something it wan not designed to do happened.
I'm not entirely convinced that most ARFs are
designed as "classically" as were the earlier models. This one in particular is really just an iteration of a very popular model from a few years ago. The way it performed for me, I'd suggest that the mfg didn't do any design beyond duplicating some measurements. When his "design" came down to choosing the components, I'd suggest he didn't do anything close to the rather exhalted idea that he figured out how much stress two sheets of very crappy liteply could take and decided that would be perfect for providing "crush protection in the event of auto accident". You seriously believe that stuff?
It's kind of like back in the 70's when they started to make cars that crushed on impact to save lives. Everyone thought it was a great idea. Then as soon as they had a fender-bender that cost $3000 to fix, they all complained about the "Crappy way they build cars nowadays"
And today our cars are designed to crush appropriately on impact to save lives. Darned if they didn't change some details along the way. Changed some materials. And darned if I'm not suggesting that the SkyBolt would benefit from a slight change up in the strength of some materials. Just like my Sukhoi needed. And the Monocoupe. see a trend here? Those failed in "normal flight".