Skycam41

Perhaps this topic has been flogged to death, but did your Sig Somethin' Extra come out tail heavy? I have an Irvine .53 with a Tru Turn aluminium spinner on it with the flight battery pack shoved right under the fuel tank as fas as it will go and I am still really tail heavy when balancing at 3.5" from the leading edge of the wing.
Cheers
Mike

Spicoli

I have built 2 of them.They both turned out tail heavy.I got them to balance by putting a 3/4 inch block behind the motor mount.

RCaeroguy

My Feedback: (4)

Just so I understand, you attached the motor mount to a 3/4" block? The mount is 3/4 of an inch away from the firewall?
Sorry for being dense, just trying to understand in case I have to do the same with my SE. I do plan on using a .61 4-stroke though.

pdansalvish

My Feedback: (23)

I have the SE ARF with an Irvine 46 and it is nose heavy.

smokingcrater

two SE's with an irvine .53, both right on the exact cg. wish i could actually move it back a little, the battery and electronics are behind the wing tube already.

Spicoli

Vacinekm- I just measured it .It is a 1/4 inch block but you have it right idea.The same could be accomplished by having a motor mount with long arms and mounting the motor as far forward as necessary to balance.Moving the engine forward a little bit has quite an effect on the balance.

DeadSticker

My Feedback: (18)

I have 3 of em and not a one has ever come out tail heavy. I even have had to move it back 1-2" to get them to fly the way i like.....

xp8103

My Feedback: (16)

It's got to be a wood selection problem at Sig. This plane is so simple to build and unless you deviated significantly from the plan, the balance shouldn't be that far off for the engines listed here. I even made my rudder a bit larger and with the battery directly behind and RX directly in front of the wing tube and an MDS .48 on the front, it was a little on the nosey side. I have put my battery pack back behind the servo area and put my RX behind the wing tube and don't use a spinner and it flies MUCH better. Sounds like if some of you did that you'd be having a tiger by the tail.....

RedWing

My Feedback: (4)

With the battery and receiver behind the fuel tank.
Balanceed at 3 3/4" back.
I have yet to fly it.
I think that is fine to start out with.

I have a trainer, sport plane and a zagi and have been flying for 2 years.

What do you think?

Also, I am just using expo, my Flash5x does not do dual rates with expo, so I will just use expo for now.

Bill

Mettler1

When I built my SE a year ago I would have had to added 8oz of lead to the nose to balance it at 3.5 inches. Did my own calculations and found 4.25 inches would be the balance point if you figure in the ailerons. That's 30 percent of the average wing chord including ailerons. So I set up my balancer at 4.25 in. and it balanced perfect at that point. Flown it that way since. Gets slighty tail heavy at the end of the tank of fuel but it's such a forgiving airplane that it's not a problem. I'm not saying you should do the same but you do have quite a bit of leeway on the balance point. The SeE is still one of my favorite planes and just a ball to fly. Enjoy. Check this CG calculator.http://palosrc.com/instructors/cg.htm

Tall Paul

The c.g. on the SE plans is just plain WRONG!
It's at 25% of the m.a.c.
The plane is a log with it there.
IF you can handle manuverable planes like the SE can be, moving the c.g. back an inch OR MORE is common!