got a hanger nine cub arf and i think that it is probably one of the best quality arfs that i have seen.

saito 72 with a 13x6 prop balanced per manual, engine thrust angle set as it came from factory. trimmed to fly level, hands-off.

when i first started flying this plane, it was very easy to nose over when landing when the plane would stop rolling, no matter how much up-elevator i threw in. had very experienced pilots fly it--same thing. moved the landing gear 1/4" forward and cured the problem.

when taking off, it was extremely important to have plenty of speed or the plane would tip-stall. checked all the incidences and found the wings to have 2 degrees positive when compared to the stab. talked to numerous people and as they suggested, shimmed the back of the wings to bring it to 1 degrees positive.

here's my question:and what i'm fighting at this time: as i throttle up to take off and keep the plane going straight down the runway w/ the rudder, the tail will come up and continue to go up and over unless i pull in some up-elevator which results in the plane lifting off. is this normal for a cub? i know i have to put in up-elevator to take off anyway, but there is such a fine line between keeping the tail from going over and the plane not reaching enough speed to take off yet b/c i put in enough elevator to keep the tail down, it has no choice but to take off. i have a third scale laser and you can run it with the tail up for take-off all day long and it will never come up and over. if this is normal, i just need to get used to it. if not, your suggestions are appreciated.

thanks,
roy

Being a Cub Flyer myself...I'm thinking you need negative incidence, not positive. See Pic of Gold berg Cub....notice the negative incidence ?
It measures 3/8 ". Yes, three eights of an inch.
MUCHO !!! I've been flyin' this Anniversary Cub for about 14 years. That straight edge is aligned with the horiz. stab.

If you have down thrust in the engine...take it out...it is not needed, and is compounding the problem.

Is the plane super nose heavy ?

And tip stalling... There's something seriously wrong here. Is there a warp, or any wash-out at the tips ?

( and to show I wasn't cheating )

The wing has a 9" chord.....
3/8" difference..(incidence)...
Using an angle finder...

That the needle isn't perfectly centered....
and we see about 5 deg. of angle....

So let's call it 4 deg., shall we ?

Just some food for thought...76.ta
Just for the heck of it, I checked the trim setting on the transmitted from yesterdays flight...and the elev., and it appears to have 2 clicks of up trim...

Sounds way nose heavy too me.

76:

I've also got the H9 Cub but with a Magnum 52 4c. To get the cg,
I had to use a Higley Heavy Hub. My plane has never nosed over
or on take-off has the tail gone past level. A fellow flyer tried to
pull his up before it was ready to fly and it did a tip stall that was
not pretty. I have to agree that it has to be nose heavy. Does the plane not want to slow before touchdown ? The factory setup
for incidence was right on and it flew great.

Randy

i appreciate your replies. i have balanced the plane out numerous times w/ numerous people looking at the balance and it is nowhere near nose-heavy. i will definitely check out the engine thrust-line like you suggested, dave. randy, if you could please let me know where you check your balance at (how far back from the leading edge of the wing), as well as what the incidence on your wing is compared to the stab, it would be appreciated. we put six incident meters on the wing and then in every combination--some one wing, some on stab-- and couldn't detect any twists.

thanks again,
roy

What do you think about the neg wing thing I proposed ?

I think a Cub's a Cub.....

I didn't know mine had so mucho neg., until I checked...

Mine will 1/2 "out-side loop" from inverted flight...I've not seen another Cub do that.....Good Luck and....

roy:

From the LE the cg is set at 3 1/2"
I don't know what the incidence numbers are. I just screwed the
wing to the saddle and flew. Sad to admit that in 40 years I've
never checked incidence or know the procedure.

Randy

I have had 2 Cubs and 1 had to much incidence or lift in the tail feathers, to solve the problem I added about 2 degrees to the front of the wing. The birds tail would lift to high and then the wing had to much down force and over it would go on its nose. the Cub I have now has about 2 degree up in the wing and the tail is level with the fuse I hope that helps you. Get one of those GP laser incidence meters and check them out you would be surprised what you find. I had a AT 6 that had 1 degree wash in on 1 wing tip and the other had 1/2 wash out on the the other.After finding this I called the Kyosho supplier and they replaced the wing, and the new wing is 1/2 wash out on both tips now and the plane flies great... It pays to check out those little things before you have big problems

The one I had also flew great with factory incidence. I had an HP .49 4 stroke in mine. I don't recall having to add any weight anywhere. I flew it off a grass field and didn't have any problems you don't have with any taildragger this size. Just held a little up to keep it form nosing over on takeoff.

Oh yea I forgot to say that not to long ago I put a OS FA80 4 stroke in this bird and a 12-6 prop. well let me tell you the very instant that this bird becomes airborne if you have more than 1/2 power on IT make a 90 degree left hand turn and climbing out just a flat a take off as you have ever seen. If you advance the power slowly then it will stay on the runway just like a arrow.