A friend was flying this plane with a piped Rossi 40 (heavy and underpowered) when a case of high speed elevator flutter exploded the tail feathers and "boom boom, out go the lights". Since the price was right I brought it home for some lousy weather entertainment. It now has a new tail (Morris Knife clone) and I put the tail servos in the rear of the fuselage to eliminate those worthless plastic tubes. Man, that covering they used is a mess.

Does anybody know where the CG should be? The front of the wing is slightly tapered back so I'm not sure where to measure back from.

With the added rear weight from moving the servos back, I'm guessing that it's gonna be pretty tail heavy (even tho it was a little nose heavy before) so maybe that 60 OS in the nose will help counterbalance the servos and have plenty of power to pull this overweight rascal.

Any help would be greatly appreciated.

CG? Fly the plane, how far off could it be?

Your right, those planes are bricks. Back in the day. flew them on OS 61 FSR's with the sevos in the tail, too.

If you wanted a real hoot you could have tried what I did with mine.

Relocate the rudder just aft of the wing and make a flying wing out of it. I worked very well until I tried a down wind take off, it didn't like that one bit. Then again it turned into a bunch of bits. []

I fly this plane all winter....it's my beat around winter flyer. You are right, the covering sucks big time...it's sticky backed. After a few cleaning off of oil and muck...the sticky substance comes out the seams and looks like "nose snot"...Eeyucck. I routed my control nyrods through copper tubes to the back for rudder and elevator. I was inverted last summer, zooming by the field when the rudder control snapped and caused a lot of flutter. I cut throttle rolled her over and brought her in for a landing. I was lucky.
Ok....there is an Addendum included with the manual...it says for CG balance your Fun Tiger at the rear edge of the leading edge wing sheeting.
The effective CG range is 4- 3/4" to 5- 3/4" back from the leading edge of the wing where the wing meets the fuselage.
Hope this helps. Here's a pic....notice the brass tubes for nyrods.

I'm using the new ASP .52 2-stroke on this plane. It's more than enough power for hovering and pulling out. I'm using a MA Scimitar 11X7 prop. The plane is too fast with that setup...flies half throttle and hardly uses any fuel. The engine is developing more power, so I may have to take it off and install an OS .46. I set my CG at 5" back. At this location it balances perfect for my kinda flying.....
Keep us upto date with the servos in the tail performance.

Cheers.

Thanks guys. The old ticker can't take another too far back CG after my Goldberg 540 trial. Sounds like I'm covering old ground with this setup -- guess putting servos in the back ain't all that original...... Kit bashing is a never ending learning experience but using old stuff that's collecting dust appeals to the miser in me. This old OS61FSR with the 7M carb should run all day at the half throttle needed for the 12X6 in front.

I really enjoy getting answers from all over the world - like Guyana. Is flying inverted there the same as upright here in S Carolina?

haha....yep...Xcept we stand on our heads in about 5 feet of water...hehe. How do you guys do it in SoCal?

Cheers.

Until looking at Guyana in the Atlas I thought you were below the equator -- hence the upside down comment. Hard to stand on my head with the dunce cap being so pointy........

Shucks....just when I was havin fun with ya... Oh well, hope you find the CG info useful.

Cheers.

Flew it today. Old OS61 with CG at the rear of the wing sheeting. Zinger 12/6, 15% fuel and throws as much as I could get. Didn't weigh it but it's HEAVY. Need to add some right thrust to the motor to judge vertical perf, but don't think power will be a problem. That big motor/prop has a lot of momentum/twist. Also, lost the spinner prop (nut came loose) and the engine screamed up to 20+ for a couple of secs before I got it shut down.

Flat spins great, tumbles ass over nose very tight, roll rate sux even with BIG throws, rudder authority seems sketchy. I've only flown it twice so can't really predict how it will act after proper trimming/mixing/etc, but this high wing loading with all the weight in the nose and tail (battery is up front too) has a inertia effect that is fun when spinning around a central axis. Flies slow real nice so CG could probably move back some but I'll try to get a more predictable response to control inputs before moving. Right now it won't harrier or hover worth a crap. A Morris Knife it isn't.