ORIGINAL: AudiMaxx
The lipoly pack I am using is considerably smaller than a stock pack...so I need to know where to put the battery...without going too far back or forward. Thanks for the help
???
You can only figure out where to put the battery by trying. Put it somewhere in the plane, and try to balance it.
There are two extremely simple techniques I use to get a general idea of where the pack will end up:
1. Balance the plane without the pack. Depending on which way it tips, and how much or how violently it tips, you can make a pretty good guess as to where the pack needs to go. For example, if the plane tips toward the tail slightly when you try to balance it, you know the battery needs to go slightly ahead of the CG. If the tail won't even come off the table when you try to balance it, you know the pack needs to go way ahead of the CG.
2. Lay/tape the pack on the outside of the plane, then try to balance. If you need to hog out foam, or make special modifications to the plane, and don't want to do it more than once, you can use this technique to find the EXACT location of the pack. We're talking about fore/aft balance here. The battery being on the outside vs. the inside only effects side-to-side and belly-to-back balance.