Mine (post #60) maidened today. It went well. The Scorpion is a GOOD motor. Am considering another Scorpion for another build. Make sure to use a 20C or better battery. The 12C I used was okay but left something to be desired. Several have commented about the cg placement. Yes, it is as far forward as plans indicate. You might let it slip a tiny bit aft but not by more than a mm or two. Do everything you can to move weight forward. My battery is firm against the back side of the firewall.