upser

Hey guys my cg came out to be about 5" behind the spar is that to far and to help it should i just put some weight in the nose????

Woodsy

The normal SPAD trick is to slide the wing along the fuzz untill the CG is correct, what SPAD have you built

upser

I have built the dps and the wing is far enough forward that i can see the hole i cut in the top of the fuselage... i guess i could put a little weight in the nose huh

Tattoo

Move the wing back until the CG is on the spar. When your plane is tail heavy, moving the wing back is how to correct it!

FrankC29

Yeah it's a common mistake that beginners make (I did) to get the adjustment backwards in your head. Think of the cg as residing in more or less one place on your planes fuselage. Moving the wing forward would cause this cg point to move back on the wing, and vice versa.

upser

Thanks alot guys i was moving it the correct way but i still couldnt get it to to get the correct cg just added a little weight and am still under the regular so i am ok>>>.thanks for all the help

FOKKER DR.1

You said that you could see the back of the hole in the fuse.That means that you moved the wing the wrong way.Just try and move the wing back tords the tail and see if you can get the cg at the spar.If you don't get the cg wright you will not be happy with your plane.

Skoalz

Upser,
Just make sure you don't try to fly the plane with the cg behind the spar!!!!!!! It may make for a very short flight.

If you come down near Twin Falls before you get a chance to fly it, bring it down and I'll check it out for you.

Goku

My Feedback: (3)

I agree with Schoalz.
I know 10 times more about crashing than I do about flying, but adding weight is usually the very last thing you want to do....

I would agree with the others that moving the wing back and trying to balance it that way would be best. Also, where are your receiver and battery pack located? Any chance you could move them more towards the front of the plane? Sometimes just redistributing the weight you already have in there will help out.

Are you in BARCS? If so, you could ask any of the local club members to check it out for you or send me an email and we'll see if we can get it to work....

upser

Hey goku, What is barcs? Is that one of the clubs around here in boise? Why dont you give me a email so that maybe we could get together and figure this one out.,....

upser

Hey guys go the cg about 2 inchs behind the spar but cant get anymore movement out of the wing is all the way back.. any other ideas or will it fly with the cg there?>

ChrisSpad

NO! it absolutely will be uncontrollabe behind the spar.
A couple of things. Is the engine installed? We need some more details.
Somewhere, something isn't right. The cg should be no problem.
Do you have any pics of the plane?

Skoalz

Don't do it! It will not be controllable.

upser

Here are the pics the battery is in the front behind the gas tank////

upser

Here we go again hahaha

upser

Hey guys i have tried and tried to get the pic to dl onto the thread and it just wont what to try next

ChrisSpad

what error are you getting? The pic has to be less than 700 pixels wide.
Email them to me, and i'll attatch them for you if nothing else.

Daryl

Think of movement of the C of G in these parameters. If you want the nose heavier - make the nose longer.(that is the distance from where you want the c of g - in this case, the spar) If you want the tail heavier, make the tail longer.
: If you can't move the wing any more, put on a heavier engine, move heavy stuff like the battery, forward, of add a heavy hub - anything to get the c of g at the spar. A balance point behind the spar spells trouble with a 'normal' wing.
: In the best case senario, you may be able to kill the engine and land without damage. A BARE smidgion worse case and you might crash somewhere other than in front of you. A tail heavy Spad (or other plane) can be very dangerous and uncontrolable.

ChrisSpad

I believe i have found the problem.

The hor. stab is way too large. It should be 7" from front to rear. 2" of elevator, and 5" of stab.

ChrisSpad

one more

Skoalz

Yup! Tail is too big. The nose also looks short. If you cut down the horizontal stabilizer, you will be able to move the wing back enough to get the cg right on the money.