Sport JTEC RADIOWAVE 26% Pitts Model 12

[HRRC Flyer]

Hey Rob,

Your S12 is looking GREAT. . . . . . A little extra support here and there won't hurt a thing. Keep up the awesome work.

 

[stangflyer]

Man, you're kickin' butt, and it's looking great!!

Hey Rob,

Your S12 is looking GREAT. . . . . . A little extra support here and there won't hurt a thing. Keep up the awesome work.

Thanks guys. Appreciate the compliments. I've caught myself a couple of times doing things that I used to do when I built all my planes many-many moons ago. Old school thoughts, ideas and practices that we've all seen changed in recent years with the newer ARF's that have been introduced. Heck, I remember back in the day I was determined to not let a single plane fall from the sky due to my building. So I went over board. "WAY" over board. 1/4" x 20 steel bolts for wing bolts on a 72" Goldberg Sukhoi. NOPE, that wing never came off in flight....

. Things like that. If only I knew then what I know now, chances are some of those planes would not have been a tick on the heavy side huh??????? LOL. There is one mistake I have made on this Pitts that I wish I could go back and change. I wish I had not used the hard wood plates in the elevators intended for the control horns. I really wasn't thinking quick enough and may decide to open up the bottom of the elevators and cut those out. Good dense balsa epoxied in their places will allow for the control horns I really want to use on this plane. Hence, the reason the rudder is not completed on both sides as of yet. I am cautioning myself on many "want" to's and paying very close attention to the "need" to's. If a big 129" Yak can stay together with no more structure than it has from the factory, then certainly all those "want" to's really are un-necessary. Brett said his Pitts came in around 25 pounds if I remember correctly. I understand that the two wings and the construction will add a little weight... but it sure would be nice if I could keep this one under that when done. But I highly doubt I can do anything better or lighter than what Brett did on his.

 

[Wacobipe]

Brett said his Pitts came in around 25 pounds if I remember correctly. I understand that the two wings and the construction will add a little weight... but it sure would be nice if I could keep this one under that when done. But I highly doubt I can do anything better or lighter than what Brett did on his.

You can definitely build it lighter than mine...I fully sheeted the tail surfaces with 1/16" balsa because I wasn't comfortable with how twisty they felt (they are just fine on others I've seen) and my support rods/flying wires on the tail are all aluminum (braided wire will be much lighter. I also have a DA-60 and full canister in the plane, plus wing tips that are heavier than needed. All that extra tail weight adds more lead in the nose, which I was going to need anyway without these extras....I think you can get 22-23lbs with a little concentration.

Having said that, my Pitts has unlimited vertical which is more than I need!

 

[Wacobipe]

Does the trailing edge of the wings, stabs and fin get a trailing edge cap glued to them? Also, do the ailerons, rudder and elevators get leading edges installed on them. I do not see anything mentioned in the manual. Words are good...but even pictures at this point would have helped.

Trailing edge of the wings get cap sheeted...but not the tail surfaces. You form the V-shape in the control surfaces by cutting/sanding them. Just filter your way through my build thread...I documented everything I could there. You are going to find you run out of build instructions very soon from what Jtec supplies....so rely on my thread for support.

 

[jtec/radiowave]

Hey guys, We try to make them as light as possible so that they will stay together and fly. When you add stuff to it all you do is add weight. The original had open bay stab no sheeting with flying wires. We used fishing leader wire to make the flying wires for the stab.

The wings are supported in 3 places so you have lot of strength on the wings. Even on the 41% we do not sheet the tail.

We don't want planes falling apart on customers so we design them to hopefully stay together.

Rob if the stab layout is not etched on the back of the jig you need to take that up with Kevin!! he's the laser operator so give him hell!!

Al

 

[stangflyer]

Hey guys, We try to make them as light as possible so that they will stay together and fly. When you add stuff to it all you do is add weight. The original had open bay stab no sheeting with flying wires. We used fishing leader wire to make the flying wires for the stab.

The wings are supported in 3 places so you have lot of strength on the wings. Even on the 41% we do not sheet the tail.

We don't want planes falling apart on customers so we design them to hopefully stay together.

Rob if the stab layout is not etched on the back of the jig you need to take that up with Kevin!! he's the laser operator so give him hell!!

Al

No worries Al. I got it handled. I simply "split the difference of the reduced size on the plans and then added the same number of stringers in their perspective locations. Actually, it really was not difficult.

Light is good. And I am sure the stabs and elevators are sufficient the way they were designed. However as I mentioned, it was not only strength I was looking for when I decided to sheet them. It was also cosmetic. I already know the scheme I plan to do is going to require seams across an open bay.

I've been putting an RCGF 10cc gasser on my trainer for the grandsons the last few days so I haven't gotten much accomplished on the Pitts. I will probably get back on it tomorrow or the next day. I do want to get it done soon. Besides swapping out the engine on the big Yak, I also intend on putting together a 100cc'er this winter and just maybe....(fingers crossed) A 42% Pilot RC Hamilton Edge with a ZDZ 180. We'll see....

 

[jtec/radiowave]

Totally understand. Sheeting the stab is not a bad idea. It add strength and will help eliminate any flex you might see in the elevators. I don't know if I would take the chance of not using any flying wires.

My only point was about adding material due to thinking that a kit may have a weeks spot. When we and hopefully others design a kit we are totally looking for areas where we may need to strengthen or where we can eliminate material without sacrificing strength. The ability to use CAD and cut with a LASER has changed the way planes are designed and the materials used. Today you would not design and build a plane the same way it was 20 years ago. Where they used to use 1/4" material we now use 1/8" or lighter and can use different design technics to accomplish stronger aircraft that fly better and are easier to build. The design of our Extra's and MX kits are all self aligning. They basically snap together and they will come out straight.

I've been in the hobby for over 50 years and the changes just in how we do things now in the the 10 to 15 years are incredible. Almost everyday something new come up in this hobby!!

Al

 

[Snoopy1]

well do not know how I missed this thread but after 10 pages up to speed. Good looking plane and it is coming along nicely. Will be following with interest.

 

[stangflyer]

Totally understand. Sheeting the stab is not a bad idea. It add strength and will help eliminate any flex you might see in the elevators. I don't know if I would take the chance of not using any flying wires.

My only point was about adding material due to thinking that a kit may have a weeks spot. When we and hopefully others design a kit we are totally looking for areas where we may need to strengthen or where we can eliminate material without sacrificing strength. The ability to use CAD and cut with a LASER has changed the way planes are designed and the materials used. Today you would not design and build a plane the same way it was 20 years ago. Where they used to use 1/4" material we now use 1/8" or lighter and can use different design technics to accomplish stronger aircraft that fly better and are easier to build. The design of our Extra's and MX kits are all self aligning. They basically snap together and they will come out straight.

I've been in the hobby for over 50 years and the changes just in how we do things now in the the 10 to 15 years are incredible. Almost everyday something new come up in this hobby!!

Al

Oh no doubt. What amazed me about the changes and how the hobby progresses is that planes are lighter and stronger. Electronics are more exotic and unique. Engines...wow, the engines are crazy cool. I remember when my friend first introduced me to what was then, basically G.S. He was running heavy lead weight Zenoah and Quadra engines. It was so funny too. He largest G.S. plane was a 90'ish inch Edge. And holy smokes, what a behemoth whale. I think it must have weighed like 32-33 pounds. YIKES. My very very first G.S. was a Lanier 102" Extra 300. I think it came in around 36 pounds. Believe it or not, I flew it on a 3.6 Glow Moki Twin. Sure, it flew...and not all that bad. Just not a lot of pull out power. LMAO. I will no doubt be using flying wires on the tail surfaces for sure. Doubt I will do the exotic, (but very cool) set up Brett did. But still will utilize them. Besides, they look pretty cool too. I am hoping and shooting for as close to 20 pounds as I can get. Right now, the fuse in its nearly completed stage on the jig weighs 2 lbs., 5.11 ounces. The 3w 70 twin is just over 6 lbs. 5 ounces. (that is with exhaust and ignition) With the sheeted tail surfaces, I am coming in at right at an even 10 pounds. Adding the weight of the wings, canopy/hatch, electronics...(servos, wiring, batteries) I will be hard pressed to keep it "UNDER" 20 pounds. As I see it, a 50cc size plane that comes in at 15 pounds is awesome. 16-17 is still great. Heck I have seen them in the 18 to almost 19 pound range, (definitely not mine...lol) and still fly pretty good. But I think it is going to fly great. I am getting closer to a scheme too. Been looking at some schemes from other manufacturers. And still with what I have in my head, I am formulating a basic design. Now I just have to decide on definite colors.

well do not know how I missed this thread but after 10 pages up to speed. Good looking plane and it is coming along nicely. Will be following with interest.

Sweetness....thanks for stopping in and keeping an eye on me. Someone has to keep tabs on me to make sure I do this right....RIGHT????? LOL

By the way, thank you Brett for the p.m.! I do have some questions and will definitely give you a shout when I get them all wrote down so I can "pick your brain" in one quick swoop.

 

[Jetpainter]

My very very first G.S. was a Lanier 102" Extra 300. I think it came in around 36 pounds. Believe it or not, I flew it on a 3.6 Glow Moki Twin.

The first one I ever flew was a friends 30% ACE Extra 230 with a Sachs 3.2. It weighed a ton, but the Sachs ran like a top. It belonged to my flying buddy Tony. That would have been in 96 or so. We flew the crap out of it till he hit a wire holding up a pole for a pylon race we were setting up for. I still have a new kit here and the engine.