Congrats on your Viggen build, looks good! I've found the Viggen to be a great edf. Easy to fly and fairly east to build. I wasn't happy with the single layer foam-board wings or vertical stabilizer though, even with carbon fiber reinforcement. I posted my redesign here: https://forum.flitetest.com/index.php?threads/better-wing-for-the-ft-viggen.37971/