Originally posted by dntmn
Thanks for the great responces to my questions. The Greatplanes Extra 300 40 size arf requires a .40 to .51 2 stroke. I origionally had a MDS .58 which weighed 20.45 oz. I was extremly displeased with this motor and only flew once with it and had a dead stick landing. The saito 100 weighed 20.5 oz, Hopefully it will fly well with this motor my pockets are empty after the Sato 100 purchase and it would be hard to dish out $$ for a new motor at this time, I plan to practice with the GP extra, but purchase a 120 size aerobat for my first IMAC fly.
I have a couple of more questions:
If you were on a budget and had to purchase a 120 size, ARF, preferbly with a 2 peace wing for IMAC flying which one would you purchase and what power source would you use?
****The hangar 9 Cap 232 ARF is hard to beat and you can get good prices on them. The Creek Hobbies planes look good, I just do not have any experience with them***
Back to the gas tank thing. When you balence a 2 stroke empty then add fuel the CG shifts dramatacly forward. When you balence a gasses with the tank over the CG the CG remains the same. Is there different CG points depending on wether you will be installing a gasser or a 2 stroke?
***Nope - same CG pionts - the airplane does not care if you are flying gas or glow. A forward CG is OK and AFT CG is NOT! This is why you balance with the tank empty.****
Example you balence a 2 stroke type plane 4" behing the leading edge with an empty tank to mfg recomendations. You then add fuel and the CG shifts to 2" behing the leading edge. If you moved the tank over the CG with a pump where would the CG be at 2" or at 4"?
**SEE ABOVE -- balance it with the tank empty and according to the manufacturer's suggestions. If the CG Changes 2" on a 120 size plane, I would suspect that you are using WAY too large of a fuel tank.****
Thanks again for your help