Went to balance my completed SE at 3.5 inches back from the leading edge and found I will have to add 8 oz. of weight to the nose to get it to balance. I usually balance my planes at 30% of the average wing chord in which I include the ailerons. If I do this with the SE I get 4.20 inches back from the leading edge. Using this figure the SE balances perfectly. Apparently Sig only measures average wing without the ailerons. Question. Do I really have to add 8 oz. of lead to this plane???

There has been a lot of talk about the SE's CG. I fly mine with the CG 1-1/4 back from where Sig says to have it. It has no bad habits with it back there.
I have seen guys balance them at the point where Sig says to but they run into the problem like you did about adding a half pound of weight. Not good on a 4-1/2 to 5 lb plane.

You are probably balanced as is. Try it and see if you like it.

Thanks Wayne, I suspect my c/g is ok. Saw some other threads this afternoon saying pretty much the same thing. In any case I will be on my toes as I always am on the first flight of a new plane. Thanks again, Tom

If anyone else has $.02 they would like to toss in please do so!

My SE has an MDS .48 with the MarkII muffler on it and I did nothing to balance it. My battery pack was mounted on the little platform right behind the wing tube with the RX just fore of it.
The performance was pretty good. However, I recently moved the battery pack back just behind the radio compartment (cut some covering and built a little box back there) and WOW!!! What a difference! Like a completely new airplane. I never rechecked the balance after I moved it as I knew that the plane was nose heavy enough before that I was worried I would have to move it even FURTHER aft. But I like it there.

I find it hard to believe that people add all that weight to there "lightweight " planes. You should be able to move the battery pack & the receiver to a different location to achieve a balanced plane without adding all that weight.

Ditto Dave;
With proper Radio gear installation, and weight management. You can balance virtually any aircraft to manufactured suggested CG.
SE with a YS 63, Modifications only cross braces on the Stab. Battery against the Back bulk head. Servo's approx. 1" from the Bulk head. Tank on the CG.
1 little Mod during construction was to insert a 1/8" Ply with 1/4 X 20 Blind nut in each wing panel. This allowed securing the wings with no worry about a rubber band breaking or stretching etc.

Every Plane I build I use the same basic technique. Building the Fuse first then mounting Engine and Servo's, Stab and balance the Fuse at approx CG prior to the Wing ever going on. Adjustment can be finalized with Gear/Wheels Prop,Spinner style, and final placement of Battery and Servo's can be slid after the wing is mounted. Then Final Balance is to do a Lateral Balance prior to the Wing being Covered.

Well anyhow you get the picture.

Have Fun
AMA 6518

Jack, after you built your Something Extra, Exactly how many inches from the leading edge of the wing did you balance the plane? Tom

Tom
I'm at 4 1/4 " and as soon as the Snow get's off my Land I'll move it 1/4 inch back further. Right now it's extremely stable, If you want a picture of the controls I'll send one to you.

This is with a YS63 12 X 7 APC. with 25% fuel it's turning 12,3. Going to cut back to Cool Power 15% and a 12.25 X 4. Should get about the Same R's.

Have Fun
AMA 6518

Thanks for the info Jack. 4 1/4" Is where my SE balances as built without having to move anything. Why would Sig reccomend 31/2 inches. Tried to balance it at what Sig reccomends and would have to add 8oz. to the nose to get the balance there. I knew that wasn't right. That's why I started this thread. I've been flying R/C for 20 yrs. and just came back after a 5 yrs. off. I didn't think airodynamics changed that much in 5 yrs. Starting to lose my faith in Sig

Thanks for the info too. I am just completing the SE. I haven't checked the CG but a quick balance point seemed to be further back than SIG suggested. I hope to be done ina couple days and I will definately check the CG. This helps because I may have tried alot before discovering this.