ORIGINAL: SLFlt
I recently completed a Superstar 40 and rough checked the CG (pointy finger method) according to the directions. My choice of engine was an OS .46AX. The fuel tank was empty and my measurement markings were right on (3 5/8" from leading edge). The battery and receiver placement were also according to directions. The aircraft appears to be aggressively nose heavy. Obviously my choice of engine is having an impact. Almost 3 oz of weight placed (temporarily) near the tail is starting to bring it level. I have several questions:
1) Is 3 oz or more weight excessive (when does the plane become too heavy)? What point do I stop counterweighting and start to move batteries and/or receivers instead?
2) Due to a long lever arm, the farther back I place my weights in the fuselage, the less I have to use. Does anyone have any techniques to cut into the rear portion of the fuselage and place weights there?
Any suggestions will be much appreciated. If I can crack this problem, I can "maiden flight" the aircraft as soon as the weather breaks!
Cheers,
S&L Flt
The first thing you want to try it to move the battery. Disconnect it and take it out. Now put the wing back on and look at the balance. Now place the battery on the fuselage and check the balance again. Keep moving the battery until you find that it does balance. If you get all the way to where the battery will no longer go the stop there and add weight further back.
Unless it's really extreme, you can usually use the battery to get the balance right on or at least help elimate dead weight.
3oz on that plane would not be excessive
You are correct, the longer the lever, the less weight is needed
I'll elt someone else explain how to cut in a hatch.