A friend is building the Anniversary Cub in full-wing configuration. The instructions indicate acceptable engine range is .40 - .61 2-S, .40 - .90 4-S. He wants to hang an OS-91 FS on it. Sounds a wee bit overpowered to me. Anyone have any flight experience with a 91 4-S in the Cub?

Yes the .90 would be way over powered. I've done 4 of these and they had from a .46 2-C to a twin .90 4-C. The most popular engine is a .70 4-C and even that is over kill especially if he wants scale flight. You will see 2 that I did on my web site, one the WW-II had a Magnum .45 PRO which was a good engine for it and the yellow one had a Saito .90 twin in it. The twin flew like a rocket!!!!

Thanks for the rapid response GrnBrt. I'll pass the info on to my friend. I like the "War Cub" on your site. I'm in the final throes of finishing my own "War Cub". I had a passing thought of reworking it to an L-4, but decided it was too big a challenge for my first Warbird attempt. I have an old Saito-65 4-C planned for it.

Here's my Goldberg Cub with OS .91 4 stroke installed. Modified with flaps and a Super Cub cowl

Flies at 1/4 throttle. A .56 4 cycle would be perfect.

Funny you should mention the L-4 as I have the plans to a 1/4 scale that I will be reworking this year and then building from the plans, should be a fun time doing that green house!! I know a guy here that owns a full size one that's gorgeous and done in Canadian markings. I will be using his as my model just will be a whole lot of work, but fun.

GrnBrt
Using the CG Anniversary Cub, my game plan ito create an L-4 is to sheet the fuselage area of the greenhouse and apply Silver film and striping to simulate the glass. I thought it would look fairly realistic in the air and I could throw a towel over it on the ground. Any thoughts on my "Plan"? Certainly would appreciate any inputs.

It could be done but a lot of work for a cub that isn't very scale. I f being scale doesn't matter, and I would say it doesn't then go for it. It would look kind of nice in the air and so what about the looks on the ground. People have been doing things like that for a long time just so it will kind of sort of look like the real thing. Mine will have the green house and that will be some work, but fun.

But Intruder... why sheet the greenhouse area? I guess it would be a little flatter between the simulated window frame pieces, but not really that much so.

I ask because you may not want to add much weight behind the CG of that particular plane -- I shave the plywood fuselage parts when I build them, for balance reasons -- but then I also avoid using much more than a .40 size engine on .40 size airplane. The 2-cylinder 4-stroke .90 that somebody mentioned would sure make it easier to balance, if you don't mind that most of strength is going toward lifting its own weight.

Art -- I have a couple of photos from last summer's cub fly-in if you'd like them for comparison. I'd love to see how you treat the fuselage on your re-planning once you get that far. I was never 100% satisfied with how I did my little L-4, but it sure was pretty.

Oh, one more comment on the anniversary cub -- it's missing the stringer that belongs about half-way up the main (lower) part of the fuselage. It may be pickiness, but just adding that stringer makes the plane a lot better looking to me!

The plans that I am working with are from Balsa USA and it's a kit that they marketed a long time ago and it's the L-4 so no modifying needed. What I want to do is make the control surfaces more scale then they show on the plans and that's where the fun comes in. there are also a few other things that I will change so it will be a nice project.

HI

I covered my Anniversary cub in KOVERALL and RUSTOLEUM and came out very very heavy,( 7lbs+) Is full wing and I fly it at half throttle with a OS 52 Surpass and 1/2 throttle most of the time. So the 91 is way too much. If you can still do it I would suggest you go with the clip wing. It never wants to land with the full wing. We have many 40 size cubs flying at our field 260 Members and almost everyone that flys different manufactures brands (sig, great planes) feel at this size (40) the GB is the best flier in this size class.

The DiBo :idea:

Al Stein,
My reason for sheeting is just to get a little closer to the real world. This is my first attempt at scale so I didn't want to go the whole root. I have left the rear window filled in and plan to add light sheeting to flatten out the greenhouse glass area. I plan to use silver trim film to simulate the glass and that does not like curves of any kind. I will be using a glass cowl and a 65 Saito up front, which will help a little with the cg. As for the side ribbing, I had initially planned to use thin doweling and a couple of balsa formers, but your warning about rear weight has me reconsidering that. Ah, so many planes to build and so little time.

Ok,
I have a Goldberg Cub with an O.S. 91 and I think it is the perfect
airplane engine combination.

Is it too much engine, yes, so what, it' a blast.
No where near scale, but FUN !!!!!!!
It's got a throttle, just put it where you want it.

I would definately clip the wing though, it's nowhere near the same plane with a long wing, and as mentioned earlier, it
floats like crazy even with the short wing, the long wing is way
worse.

I built this airplane as an alternative to some fast planes I was
flying at the time. I wanted something for low and slow type stuff
and also wanted to try me first 4-stroke.
All I can say is that twelve years later it is still the best airplane
I've ever had in my collection. She cuts up nicely for a cub, but
with lower throttle settings, she still flys like a cub is supposed to.
Airplane has so much time on it I've replaced every hinge on it at least twice, just plain wearing them out. She's looking kinda old now, everthing on her is loose and worn, but I'm still working her as hard today as the day I first flew her, ok I lied, actually I'm working her harder.
Thought I would only fly this plane on occasion, but it fooled me
It goes with me everytime I fly.
I've got to get another one as a backup, because as bad as I hate to admit it, this ones days are probably numbered.

Did you get the point, that I like my Cub ?
sorry I rambled......

James

I guess clipping the wings depends a lot on how you want the plane to look as well as how you want it to act.

After dropping one bay, the plane's still a floater, but the change is appearance is already noticeable. Dropping two bays, you're take a model of a 36' span plane and fitting it with the scale equivalent of about a 25' wing... at that point it may act like a highly modified T-Craft, but it doesn't look like one of those and it really doesn't look much anymore like the L-4 it was supposed to be either.

So, if I were going to the trouble of altering the fuselage to make it more scale-like, I don't think I'd go for clipping the wings -- my preference. If I wanted to shorten the glide in a stand-off scale Grasshopper, I'd add some split flaps. They can be done without changing the appearance (if you really want them not to show, you can bring them forward of the trailing edge without losing their aerodynamic effect.)

My Goldberg cub, used in my avator, is done as an L4. It doesnt have the greenhouse canopy, but neither did the full scale it is modelled after. I found several pics on the internet of this particular cub. It was one used in the Pacific theater during the early part of WW2. This model is a very good flying version of that Cub. I have a Saito 80 4 stroke engine on it.