Tell me about classes of control line planes and using the 2-4-2 break

Thanks Dave.

"2-4-2(4-2-4?) break" is normally only used for large, slow, stunt models with engines bigger than .35, the engine/tank combination is tuned so that in level flight the engine is 4-stroking, as soon as a manouver is started the engine goes into 2-stroke, in this way the model is (theoretically) flying at the same speed, whether level or manouvering, since the engine slows or speeds up depending on it's attitude.
If you are after speed alone you do not want this to happen, it is intended simply for smooth, slow manouvers in competition flying.

Wilf

A 4-2-4 run is primarily used to maintain a constant speed during stunt maneuvers. The most famous engine that runs a 4-2-4 break is the Fox .35. Stunt flyers have been using that engine since ~1950. MANY other engines have been modified to duplicate that run. There are also many who go to great lengths to make engines run at a constant 2 cycle speed and use a large relatively flat prop to maintain a constant speed.

I would suggest you go for a constant speed. The benefit of the bladder, uniflow and chicken hopper tanks is to maintain a constant speed.

If you are going to step up in size, a Flite Streak Jr. or a Junior Satan would be good for a TD .09 using 52' x .012 lines.

A modern .15 can handle a full size Flite Streak or any number of modern FAI combat planes. For a faster Flite Streak type George Aldrich designed a "tweener" size called Peacemaker...which is very popular outside the USA.

You could step up to a .25 for the full size FS or and older combat ships that used a .35 but you should step up to 60' x .015 lines.

George

Rusty, one thing I enjoy about this hobby is that it does have different aspects of it. Anything I built to go fast was strictly for fun. I wish I could fly stunt better than I do. It does take repetitive practice. My son was fortunate to be taught by some of the best and his flying has surpassed mine by far. I like to build however and when I take out the sandpaper he goes running. In the event you did build a larger model, a profile certainly is enjoyable to build. Your experience with bladders and running these smaller mills will certainly lend itself to some fun combat planes. Ken

I do have a Tee Dee .09 that I've never used, and I would love to build a Jr. Satan. But I thought it needed more engine, like a .15 to .19 as it says on the old Goldberg box. I did hear someone say a TD .09 was like a TD .15 in disguise.

I like the looks of this Stunt Rocket. I have a picture of a guy flying one in my computer's desktop rotation.
http://www.blackhawkmodels.com/stuntrocket.html
Other than looks, I don't know if it would suit my needs. I probably should go intermediate first, like the Jr. Satan. That would save me from buying an engine for the Stunt Rocket which takes a .35 to .60.

Rusty, I was told a .09 will pull along a Jr. Satan just fine. I have one lonely special .15 for mine, but will prob use an .09 first. Unless I get more proficient that is.

A Jr. Ringmaster may be a good choice for your .09

Hi Rusty,

I'm guessing here, but are we talking Stunt? There really is no size classes in stunt. There is a Max size engine, but can't remember (.61-2c & .74-4c????) but you could show up to a PAMPA stunt contest, show your AMA card pay your dues and fly (beginner?) Stunt with your 1/2a stuff. If your gonna go bigger I'd pass on the .09-.19 size stuff, unless you have engine and really want to fly it, go ahead and build bigger as cost at that point is not a lot more and it would handle the wind better.

2-4-2 or 4-2-4 was the common stunt set-up, most now use a smaller pitch prop and run a more consistent RPM, the engine still 'breaks' a little but not like the old Fox .35's or like engines.

Hi Mark, thanks for the reply. I don't do anything official, or haven't so far anyway. I am joining the AMA so I can fly at a club I've been invited to join. I'm the only CL guy there, the rest are all RC and I think a lot of them are lekkies. I'm just a fun flyer, and yes I do not do many flat laps, it's always looping or some such stunt maneuver. So I'm just looking for fun toys to play with and amaze my friends and neighbors.

Rusty, the builder of that particular Stunt Rocket was our club president. He's way ahead when it comes to building. Bob is an aerospace engineer with impeccable building skills using designs and materials most wouldn't attempt. That Stunt Rocket has an all fiberglass molded fuse. It's an incredibly light and flies extremely well using a period engine which is an Atwood Triumph .49. The engine run is extremely pleasant to listen to as it just doesn't miss a beat. Bob is extremely talented and I only speak with him a few times out of the year. He moved to your state Rusty. The weight differences between his models and mine are like night and day. I can't speak for the kit offered from Blackhawk. I do recall when Larry posted the new comings of this kit, Bob offered him the pic of his plane for the box art on the kit. I know he's told me that he's retained the molds for the shells of the fuse in the event I wanted to build one. That particular plane is probably nearing 9-10 years old now and really looks good still. Ken

What about the Tee Dee .09 on the Jr. Satan, do you think it really would perform up to my hopes(you pretty much know what I like by now), in place of a Tee Dee .15?

lekkies?

I think the .09 would pull it ok, not as much speed/line tension, but should be fun. Remember this was designed for combat action with the .15, your looking for a stunt trainer?

http://www.rcgroups.com/forums/showpost.php?p=19903284&postcount=7072

Lekkies= electric

Expertienced Class B&C "stunters" have flown "2-4-2 break" since the dawn of CL history without giving it that designation.

Larger stunt planes do this well because they have the wing area to carry out slow manuvers with the style and grace that wins trophies.

Mark Boesen wrote:...Remember this was designed for combat action with the .15, your looking for a stunt trainer?

http://www.rcgroups.com/forums/showpost.php?p=19903284&postcount=7072

No I'm looking for a badass quick plane that goes where I point it in an instant. Not for contests, just to fly for fun. Since I haven't yet built a plane bigger than 1/2A, I don't have one to compare it to. But My Baby Flite Streak flies 60mph on 40' lines and will stand on the lines straight up overhead doing figure 8s(if the wind isn't blowing). So scaling up to the Jr. Satan including line length, engine size, etc, I wouldn't want any less than that.

Since I already have the .09, maybe I should look at another model. I'll also shop for some .15s just to see what I could get, but I'm hoping not to buy another engine.

I don't know, it's not a major build...maybe build it, fly it and if your not happy with the speed you could shorten the wing up a little or swap engines? To me 'Slow Combat' is still pretty fast.

So this summer I was out to the flying field with a 'gas job' and a kid walks by and says. "pretty cool, I've been thinking of building a gas plane"...we're not in Kansas anymore, I didn't really realize how much electrics have taken over the R/C sport segment of the hobby and 'gassers' are a novelty!

You're right about it being an easy build. I scratched out my Li'l Satan, all except the ribs which were the only parts still in the old cannibalized Goldberg kit box. It went together pretty quick, not many parts to it and it's a tough little bugger too. It needs a big brother.

Yeah, those guys at the club I visited looked at me like I was some sort of anachronism when I lit off the Tee Dee. I made a hell of a lot more racket than they were used to. I think I did hear a well muffled gasser that day, but they all sit around talking about batteries for entertaining conversation. And the worst part of it is most of them are a bunch of gray hairs like me. I don't know what's gotten into them. One of them said he really liked my smoke trail. I told him I can't usually see it from center circle and he offered to fly it so I could see. I counter-offered to bring a trainer next time. They haven't seen a control liner out there since 2001. I wasn't about to let him fly my Baby Flite Streak on a windy day... or any other day. My Stuntman23 has a loud smoky old Tee Dee on it, he can try that.

Here's my take on the Jr Satan. I'm actually in the midst of a rebuild currently. I do this for nostalgia and fun. This is a pretty old school plane and I'm not expecting any real performance from it. These older planes were quite limited in turn. This was mostly due to the narrow wingspan and thin wings. The real problem with using the TD .09 is weight. Any model that uses a center spar like the JR Satan, the Voodoo, the Ringmaster, the Jr Ring etc is useless. What that piece of wood does is add weight, rips out all of your other ribs in the event and of a crash, and removes the integrity of the rib structure due to the square holes made in them that just causes stress risers. So if the kit has it, remove it. It doesn't add any strength to the wing just something to glue the now weak ribs onto.

The solid leading edge and trailing edge provides the strength, and this can be lightened considerably. I use a core box router bit and remove 2/3 of that material from the backside. The skid plate on the engine nacelle/doubler is 1/8", That could be swapped out for 1/16". The bearers on the plane are immensely oversized at 3/8" x 1/2". That certainly could be cut in half or just use 1/4" x 1/4". This thing is a Sherman tank. I personally would suck the engine back trying to get the cylinder as close to the leading edge as possible. Wings in general are plagued by their faster turning rate and therefore when using hard tanks the fuel runs away from the pickup. A bladder setup is lighter than a metal tank. What I'm suggesting here, there's a lot of fat that can be trimmed here. Tapering the booms and stab etc. All this will keep the plane light. Then I would say yes, the TD .09 is a capable engine here. It isn't the size that's the problem but the overall package.

As with any wing, bladders work and are simple, light and generally problem free other than them popping from time to time. The TD .09 with no fine threaded needle valve would probably not fair well with the stock unit. A remote needle like the OS #1A would probably be in order. A fine threaded remote assembly could also be made using a 128 TPI spraybar and needle from a product engine. I've done that as well . Ken

Hmmm, the BFS has a center spar too, and the ribs are made of such light soft balsa I doubt if they could support any sort of crash. Luckily it has never crashed. When I was building it I could barely touch a rib without chipping a piece off of it. I guess saving weight is why the LE was two 1.8" sticks glued together and then rounded off. When I build the Streak/Hyper Viper hybrid I'll have these things to think about.

My Goldberg Li'l Satan kit had a deep groove cut out of the back of the LE, but it was broken so I made a new one out of a square dowel and didn't gouge the backside out. Every other part i used was harder balsa too. The AUW was 4.6oz with a Black Widow, I wonder what the kit balsa would have weighed. Not that I can change anything now, just seeing more reason to what you just said about weight. Maybe that's why I was told it would be demolished after the first crash. Mine has survived a crash unharmed, but is not as zippy as I expected. Learn something every day.

Rusty, that's quite different in that plane. Those TWO spars are critical to that wing design and can't be eliminated. The Baby Flite Streak has no solid leading edge but a built up planked version. The Brodak Jr Lightning Streak has solid leading edge and trailing edge which is virtually identical and NO single center spar. That's what I was making reference to. The strength is in the solid leading edge. Any combat wing today that's going to sustain any types of load are going to have spars as in your Flite Streak. All of my foamie wings utilize that type of construction which is the key to strength. I use spruce, white pine, or bass on the foamies. Prior to gluing the spars into the foam, I use a continuous strand of carbon tow mixed in thin white glue directly under the spar running from wingtip to wingtip. The single spar running down the middle of the wing is really like I said doing no more than providing glue area.

Sterling would suggest to slip the ribs onto that piece of stock and glue the leading and trailing edge only. Remove from the building board and check for warps. It was then suggested to block the tip or tips to straighten and then glue that particular member. It only really provided wrack resistance to the wing. With iron on covering today any wing can be trained to do the same thing as that member did. Ken

Rusty,

I would recommend that you build the Jr. Satan per plans and install your .09 in it. Flying on your 40' lines should provide enough excitement.

I had a OS Max-III .15 on mine and I flew it on 52' lines.

If I remember correctly the 1/8" plywood used was lite ply. I no longer have the plans, I built it many years ago.

George

Edit: Forgot to mention...its a 4-2-4 break. It runs 4-cycle during level flight and changes to 2-cycle when you do climbing maneuvers. When not climbing, it returns to 4-cycle. Most engines going from a 4-cycle to 2-cycle do not return to 4-cycle...that's the difference.

The AMA engine classes began with Free Flight, so that engines of like displacement could be flown against each other. In CL, they're mainly used in Racing and Speed classes, where you're trying to fly as fast as possible given limited engine capacity. You also have engine classes (though they don't actually follow the actual class sizes) in Combat, Carrier, etc. In Stunt, it of course does not matter - in the past there was a maximum engine size but I believe that's been scrapped - some people run HUGE engines - .70s, .80s, these days in Stunt. They do mandate the size of lines you need to use when using engines above certain displacements. To complicate things, there are AMA rules (link below) and FAI (International) rules (most FAI "engine performance" classes standardized on 2.5cc engines).

http://www.modelaircraft.org/events/compreg.aspx

All this is for competition, of course, when sport flying, anything goes as long as you don't exceed weight limits and use appropriate lines. I'd say if you live in the US, you should join AMA - you get a nice magazine every month, and you get insurance.

About wing construction - I agree, top and bottom spars make a lot of sense. The Voodoo type wing did have it's advantages over the later D-tube wings in that it was easier to repair, perhaps - that huge honking leading edge was what held the model together even though it was heavy. British Combat model construction was similar, except the front spar was a full 1" thick and the ribs were just 1" wide strips - the wings were flat plates. I'm a foam wing type of person, there are advantages to those, too, they can be built cheaply and can be made very, very strong. The typical Combat foamie can be planted straight into the (reasonably soft) ground at full speed with no damage. The Li'l Satan and the like are very old designs - they are tiny in comparison to modern day 1/2-As. They fly OK, I wouldn't use them in competition, but they make great sport flying models.

About the 4-2-4 break, yeah, this was a way to keep the model from speeding up on the down legs of maneuvers. You can get almost any engine to do this, even a Combat engine running on pressure. Running things this way does cut down on the power you get out of the engine, but that's not a concern in Stunt. They still use the "break", though these days it tends to be more subtle. Even the tuned pipe setups (which run at relatively high RPM) will "break" if set up to do so. The really big engines are set up to run a constant 4 cycle.

Iskandar

That clears up my questions, I appreciate all of the detailed responses. Thanks a lot, guys.

Hello Iskandar --

It's nice to see you posting here in the COX forums. Have you returned home or are you still living here in the States? We have a forum called INTRODUCTION where new posters can provide some information about their interests and experience. I certainly encourage you to think about adding your name and background to the thread.

I've read many of your posts in RCU and RCG -- you're quite an enthusiast about C/L. I post in RCU as Andrew and in RCG as Andrew0820.

Welcome to the forum.

andrew