I've been working on this plane off and on for several months. Tried to balance it last Saturday and after building a box in the rear for my battery (6V) it was way tail heavy. I'm not sure how we got the location that far off but we did. Yesterday I glued in some hard wood to remount it and I think I'll just cover over the location. It's the large lightening hole just aft of the trailing edge wing mount. I've never had to fool with any of my plane's batteries so I thought why make another access. I've gone with the CG in the middle of the recommended range, 5.5 inches. I made a balance rig with erasers and rods, and also have the GP balance machine but still balancing the plane was a bit odd. If I held the plane perfectly level and placed the bat just right, it would stay there. But if I tipped the plane a little forward or aft it would drop down that way and not come back to level. Is that clear? I'm not sure I'm expaining clearly enough to get advice. Someone explained a way to balance using string and hanging it from the ceiling from the engine shaft and tailwheel. Anyone remember that? Is it better?

The only thing I can figue out that I did to screw it all up was that when I was looking for the correct balancing spot for my battery I had a HS5635 Hitec digital servo in the rear. I changed it to a digital Hitec 645MG. And fabricating the box and plus the servo must have made the difference.

Hanging from a string to the prop shaft and tail wheel will allow you to balance the plane in roll - you can tell if one wing is heavier. What you are experiencing with your balance setup occurs because the cg is higher than the points you are resting the plane on.This works fine, it is just a little tedious. If you turn the plane over it will be stable on the balance . If it is nose heavy, the nose will slope down when near balanced and will stay put . If you are way off it will swing way down. It is balanced when the plane rests level. I almost alway rest the bottom of the fuse on a small cross beam at the intended cg. You know it is right when a little added weight on the nose causes it to fall forward and a little removed wewight causes the nose to swing up. It is actually more sensitive than when the plane rests on supports above the cg.

I think I understand. I think the plane would be described as a mid wing and I'm balancing it inverted. Thanks

don't give up on that rear battery location just yet. This plane can easily be flown an inch farther back on cg than where you settled on. it depends on what you want the plane to do !

I'm truly not a 3D pilot though I try some stuff. My twist was tail heavy and I had to add weight to it. Over time most of it has come off and I just keep flying it. Maybe it's like the frog in the pot. He supposedly get used to the water as it boils and doesnt jump. I've got the wood glued in to mount the battery to, and it's fixed so I can move the battery fore and aft about an inch either way. I'll mount the wing and tyrap it in and then cover over the spot. If I need to access it I'll just cut the cover again.

sounds like your balance point will be right for you ! when you get the cg way back, this plane will get pretty wild

Well to update my last post. I went today to finish it off. I mounted the wing again and set the battery on the new mount spot and the balance was off again. Then I remember (smack forhead) I didn't have the cowl setting on it when I marke the spot. After fooling with a while I found I could go ahead and mount it there and add 3/4oz lead at the the tail wheel and it's fine.