Originally Posted by RCAV8T0R
...with your batteries. Not enough prop speed with 3S to keep her flying properly.
Nowhere in the manual does it say this ship can be flown on 3S. At the same time it also doesn't say you can't use 3S packs but (usually) the specs are the best starting point. This was also confirmed with the Peaks 42 flight review done by NP.
Big Bird (read heavy) needs more power & rpm's provided by the 4S packs. She'll lift off nicely with just a little over 1/2 throttle. Been flying 4S 2200 25C - 30C packs with excellent results & she has the proper power to get out of (& in) trouble.
It's plenty nose heavy (stable) at the factory mark & it's the best place to start. With the (4S) 2200 packs the front edge of the battery is about even or inline with the back edge of the front foam bulkhead with the hatch off.
For my Dynam Bipe, the CG is behind factory spec since I've been moving mine back to get more of a neutral flight attitude when inverted so I can lay off the elevator to keep her level.
Get a 4S 2200 pack before you try flying her again. You'll have much more potential for a successful flight by doing so...
Thanks for info, I thought 3s was OK, seems at one time 3c was listed as being needed to complete on website, I ordered 3c's with plane. Could have read it wrong on requirements though, I did not double check with manual just assumed 3c was right size.
I do have some 4C in mail for the big Waco so will be sure and use them on next try.