Smacka

I have just completed the subject build. Page 22 of the manual states the "CG" specs are 5 7/8 to 6 1/2 inches back from the leading edge of the main wing.



I cannot get close to this range. I have attempted to balance the bird , inverted as stated in the manual, using a Great Planes "CG" stand. I would have to add well over 5-ounces of lead way far back on the tail in order to come close to this "CG" range.



Has anyone else had this issue? How did you resolve it? What am I doing wrong?


Thank you!
Smacka

delman

Which engine are you going to use ? I recommend at least to start with go with the forward cg suggested - maybe even 5 1/2. After flying it you can further adjust if necessary. Mine lands a bit tail heavy with a 3 point landing stance with cg at 6 powered by a saito 91. It still has a half tank of fuel left after a 10 minute flight - this would make it fly more tail heavy if the tank was closer to empty.

Smacka

Hi Delman:
I have installed an Evolution .61, which is another reason I am puzzled by the "CG" issue. I was thinking with a .61 engine, hitting the stted "CG" range would be a no brainer. Boy, was I ever wrong.

Thank you for your help!
Smacka

delman

The evolution 61 two stroke is probably 3-4 oz heavier than the saito 91 including mufflers - also used a dubro 1 oz spinner nut instead of the regular spinner.

delman

Smacka have you flown your plane yet?

Smacka

Nope, not until next spring. I was able to work through the "CG" issue. I located the battery under where the main wing bolts to the fuselage, and was able to get the balance point at 5 3/4". I believe it will work just fine here.

Keeping my fingers crossed. ..

Thanks for your input!

aa2dd

the cg suggested in the manual is to far back. I would suggest that you start at 5.25", and save yourself a disaster.

Bruce

Tcat1000

My Feedback: (34)

Hi.........I mounted the elevator & rudder servos at the rear with steel linkage rods & have the EVO 100 2 stroke on the nose. I also balanced it at 5.00 inches back & it flies better there. I get no ballooning on final & it has unlimited vertical. As stated above, the recommended CG is too far back.

Tcat

Smacka

Thank you all for your input! The last thing I need to do is to install one-inch servo arms (arrived in the mail today) on the elevator and the rudder so I can get the recommended surface throw. Right now, I cannot get the full throws. I already had one-inch arms on the ailerons.

I believe she will fly her nuts off

Thanks again for your help!