Step 7: Final touches and wrap-up
When everything looks the way you want it, it is time to stain the balsa, insert them permanently (and fix them in place with a binding of thread) while tensing the wing fabric.
Finally I added 2 pairs of elastic ties (to at the top, 2 at the bottom) between the free center flaps of the two wings so they're under tension when extended...
As you can see in the last picture, they are pretty impressive when unfolded, and the only drawback I found so far is that the batteries drain pretty fast.
If you fold/unfold them a few times in a row, you can tell they're starting to slow down... I may modify the batterypack so it takes 6 14500 LiPol batteries in pairs (they do about 3.7V each) or triplets (11.1V, tests on the web show that these motors work fine on 12V, and it'll increase the speed too, which could be a bonus). That way I have 3 or 2 sets of rechargeable batteries with a good capacity. If they last a single day, I'm happy... We can recharge them over night! ;)