RE: SK3 F3A motor-same as Hacker F3A, but 29% of cost ..?
It has been shown that certain chicom factories build items for different manufactures under different contracts on the same assembly line, The higher priced/quality product gets better parts, more attention to assembly details and more stringent testing while the similar but lesser quality product gets lower quality parts, less attention to detail and less testing.. They may look similar and have similar specs but the parts,process,and testing is different resulting in good, better, best finished products.
Clones fall under this but copies are a bit different . Copies are chicoms taking a design/patent from someone else and making that product to look exactly like the original right down the nomenclature and artwork. Using less expensive parts,less quality control and selling it for way less than the original while the original manufacturer gets nothing but headaches over it.