This is a build I started almost two years ago. So stack is 30.5mm and 3" frame is super beefy 4mm by 2019 standards. It's heavy at 205g dry. Three inchers weigh half of that now. I was afraid it would be a total disaster. But after having flown a couple of packs I kind of understand why some people like heavier quads with more inertia and more "throw".