RCU Forums - 4* kit?

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Wings, I was skeptical of its size and thickness (and only using one instead of two) but I have to admit that the two 4*40's that I've had haven't had a wing failure. I'd still prefer to see two of them, ala LT-40 type construction. But I do have to admit I have not had a problem with the wing.

Bob

As soon the two first w1 ribs fit perfectly against each other and that you make a good 30 minuts epoxy gluing you won't experiment any structural failure in my opinion .

The kadet LT 40 is build like a tank (wonderful trainer)

Hey wings, I am about to build a 4*40, useing the engine from my LT-40. Post a picture when you are done, and I'll do the same.

btw, it may take me awhile, I build at my grandfathers house, and scheduling is difficult so we only work on it once or twice a week[sm=crying.gif]

Hey,

I am posting pictures of my progess on my site if you like to check it out. I was going to try to make a cowl. After thinking about it a lot I think I will just leaves the cheeks on this one. I am afraid I will screw it up if I try to make a cowl, specially since this is my first kit.

[link=http://home.insightbb.com/~brownmattt/fourstar.htm]My four star progress[/link]

Thanks,

Wings

seems you are on the right track !!

I think it will be easy to find a fiberglas cowl for your four star.
I don't have any link, but I know that some fiberglas parts manufacturer sale that

Nothing wrong with leaving the airplane as it is, specially for your first low winger. You might need to make quick engine adjustments at the field, an unexpected encounter with the ground can make repairs more tedious too. Leave it as it is and learn the most you can of this first low wing. Later on you could give the model a "face-lift" with new nose, new turtle deck, shorter wing,...etc . Seems you are moving along quite nicely as it is. Love to see the final shots.

the Mid Star 40 is even better in my opinion as a second plane, I have one as well set up like a taildragger (builds both ways) It has a 46FX and is a great plane to fly, docile and lands as slow as most trainers. I also learned with an LT-40 and the transition was easy. I have flown 4*s and they are good to so its pretty much your choice...look on sigs website and compare.

Quote:

ORIGINAL: cappio777

Nothing wrong with leaving the airplane as it is, specially for your first low winger. You might need to make quick engine adjustments at the field, an unexpected encounter with the ground can make repairs more tedious too. Leave it as it is and learn the most you can of this first low wing. Later on you could give the model a "face-lift" with new nose, new turtle deck, shorter wing,...etc . Seems you are moving along quite nicely as it is. Love to see the final shots.

cappio 777 is right, you don't need the cowl, but if you want one, go for it

Nice build there Wings. Can I suggest a little tip though? You might want to drill a couple of small holes (1/8" should be fine) through those wing ribs, one in front of the main spar and one behind the main spar. Do this for all the ribs in the wing except the tip rib and the root rib (you don't want holes showing up under the covering of the tip rib, and they're unnecessary in the root rib as you have the servo opening cut there.) That way when you come to cover the wing and you start shrinking the covering material it won't balloon up on you - all the hot air that would have been trapped in between the cells in the wing will escape through the little vent holes you drilled. Makes it much easier to shrink to a tight smooth surface :)

Keep us posted on the build!

Cheers,
Neil.

Try http://www.fiberglassspecialtiesinc.com, but at this point, don't get your hopes up.

I tried to get one there in the spring and Larry, the owner, tried very hard but the one he suggested just wouldn't fit - it was really close, but it would have cracked. Remember, that was earlier this year. He may have managed to get one to fit by now... He was a really good guy to work with.

I know that there is a cowl for the 4*60.

Bob

Making a balsa cowl to round the nose off a bit shouldn't be a big deal.
Maybe you can just add some triangle stock to the top and bottom of the cheeks and a plywood ring on the front, add some sheet top and bottom and sand the whole thing round.

Bob,

I couldn't get that link to work.

Wings

Try it again using this link. The fault was mine. In the link above, I inadvertantly used a comma which became part of the URL. That's why it wouldn't work. My fault. Sorry,

http://www.fiberglassspecialtiesinc.com

Oh, and mindwarp, good idea. Should I tell everyone that all I do is lay on the covering, then start talking? Shrinks right down!

Bob

Hi Wings. Reading the thread and your progress so far, I thought the following hopefully supportive comments and suggestions may perhaps prove of interest to you.

Congratulations on the choice of SIG's Four Star 40 kit. You've chosen arguably the perfect progression for the more confident R/C pilot who is comfortable and competent with the LT, and ready to progress to the next phase of the learning curve. The LT is itself arguably the perfect trainer and was an ideal choice for your first aircraft. So that you can better appeciate where my perspective is coming from, I freely admit to a bias or prejudice as having given considerable thought to it, my own choice for a trainer and subsequent progression some years ago was LT-40 to Four Star 40, both from kits. Albeit not the only choice, it was a solid and one I would repeat without hesitation. These days my personal preference is for sport pattern models, though I still very much enjoy my Four Star 40 and similar sports flyer models.

Adressing some of your concerns.

The Four Star 40 is an easy flyer and great first taildragger with no mentionworthy vices save a characteristic it shares with the LT in that it will float forever if you carry excessive speed on approach. You are already used to this from your LT so adapting to it with your Four Star shouldn't be an issue. The Four Star can safely be flown as slowly as the LT on approach. However, different from the LT it is highly aerobatic, much faster and nimble. An absolute delight to fly.

The Four Star 40 doesn't need much engine. Your current engine will do just fine. It is a small and very light model with a low wing loading. I've used a few different engines in mine and seen 'em fly with all manner of powerplants. The powerplant I found best matched of those I own (predominently two strokes) was my Super Tigre ST S40K which is very similar to an OS 40FX. I've tried grunty 45s (Enya CX) and 46s (OS FX), but frankly they are excessive power in this light airframe and personally I preferred and reinstalled the .40 mentioned. That said, the Four Star would fly OK even with a plain bearing low powered .40 such as the FP and is probably ideally powered by a four-stroke. I was tempted to put a .40 Surpass (my only four stroke) in another one and from what I've seen of those powered by Surpass .52s and Enya .53s, the power of even a .40 Surpass et al would be adequate.

Build it as per plan except perhaps giving thought to the the following considerations. Beefing up the tailwheel by lashing out on a DuBro tailwheel bracket and mounting it on a ply plate glued to the bottom of the fuselage will offer greater longevity. You don't need or want to fiddle with altering the dihedral or beefing up the supplied ply wing joiner plate. The full span ailerons are quite large and powerful. With wear, do watch for flex in operation around the aileron joiner. From my own experience, I would recommend reinforcing this area with a light layer of glass and epoxy and ensuring deep penetration of the joiner into the aileron itself. Insofar as mods go. That's it. At this stage of your R/C experience and with this model I suggest you forget the idea of cowling it. Keep it simple. If you decide you want a cowled model buy one. It's a less painless way of discovering how much of an infernal nuisance cowls can be even though they do look good. Pertinent to others suggestions of it not rolling or snapping fast enough, my only comment is that if a faster rolling and snapping model is desired, it is smarter to buy a Sukhoi or CAP, or if something which flys like an arrow is desired, buy a patternish ship. You already appreciate this I'm sure, but I mention it in passing. Speaking plainly, the Four Star 40 default OOTB is the right design for you now. As it stands, there's nothing shabby about the Four Star's rolling performance in its class and you won't be disappointed with either your expectations of its performance or the progression.

If its not in the air already, I can see from your progress that it won't be long. Set up and trim her true pre-flight, relax and confidently enjoy your test flight. You are gonna' love this bird. Like SIG's Four Star 60 and Astro Hog, the design is pure sport flying magic.

IMAO this guy work for SIG :D

but he is perfectly right !!!

Thanks for the advice. I appreciate it. It will be untill after Christmas before she flies because my wife insists I wait because she has already informed a relative what covering tools I want, so I have to wait till Christmas for the covering tools.

I don't mind though. I am in no big hurry. Its cold here and I want to do the best job I can on my first kit.

Thanks again for the reassurance that my decision for a four star was a good one. I will keep my web page updated with the progess. I've been a little under the weather this week, so not much getting done on it.

Thanks,

Wings

I'm also in agreement with sigrun about the many good points about the 4*40. But I'll make a couple of minor exceptions...

I also built my first 4*40 with a 3rd party tailwheel bracket... but it added weight to the back (though, not much) I had to compensate with weight in the nose (again, not much)

In retrospect, the next two that I've built have had the stock tailwheel, but I've added an additional CA hinge. That keeps the tail lighter, and beefs up the rudder to support the tailwheel.

You might want to add some 1/4" triangle stock to the fin/stab junction.. nothing heavy.

And, when you think about it, there isn't that much load on the tailwheel anyway. It's not on the ground for that much time. With the extra CA hinge, I haven't had a problem with stock tailwheel setup, and I fly off of a well manicured grass runway..

Before you ask why I've had so many 4*40's, the first one was crashed due to a bad aileron servo (true story, as I said earlier), the second one is going to be sold because I built the 3rd one, which was kitbashed with a S8036 airfoil.

Again, the 4* is a great plane (notice that no one here has had anything bad to say about it). You're going to enjoy it.

Bob

Quote:

the second one is going to be sold because I built the 3rd one, which was kitbashed with a S8036 airfoil.

I lost ya there. What does that mean?

Wings

he means he build a diferent wing, changing the airplane general behaviours

Wow,

Must be a decent plane or he wouldn't keep buying them:).

Wings

Sorry about the confusion... and I'm not trying to take over this thread... I just wanted to say that I've had 3 of them, and I wanted to clarify that the reason for so many of them was NOT because they were unstable and crashed (quite the opposite). salmonbug knew what I meant. Yeah, it's a decent plane.

Bob

This may be a stupid question. But can I assume it is necessary to put some holes in the firewall for the fuel lines? The instructions don't say. It seems that would be the only way.

Thanks,

Wings

You have assumed correctly my dear Wings. ;)

Doesnt the firewall already have one big hole in the center towerds the top? I am building the 60 so mabey its different. Also, I dont know if your kit came with it, but my 60 kit came with fiberglass cloth and i just wanted to say dont use it, its very thin and brittle compared to the other fb cloth iv used. I think i have Great Planes cloth on my avistar and its very good. Epoxy it dont CA. Just my 2 cents.

NMTR13