He says he's building out of foam, so that actually makes it harder to stay under weight. You have to figure every wire, wheel, pushrod, piece of tape, etc. I don't mean to discourage you at all though. Have a great time working on the plane and give it a try. That's how aviation started so enjoy your successes and learn from you failures. I do still believe though that you'll have a more successful first run if you'll go down to a smaller battery.