CEF speed contest Design Discussions (2014)

Wow, that is great Jim, thanks! This is my first weekend home in three weeks and it is rapidly becoming busy. I might actually be able to get a couple of flights in and maybe even try a prop or two!

Hi Guys

Yesterday I had a chance for my reed speed model.

It was unfortunately not a happy ending.

I think the engine was a bit lean, so it did not unwind in the air. So it was a bit slow. But the plane actually still kept the lines tight.

But I did not have any UP. Do not know why?? So after approximately 7 laps, I hit the deck.

Here are the remains:


I will see if I can put it back together today or tomorrow.

Theo

Another one bites the dust <<< it must have been going pretty good to come apart that bad >>> Sorry to see that Theo . Like mine the beauty has worn off , glue it back and turn it loose !!      I think I have my engine problem straightened out , soon as I can get back on the aeroplane  I will let it sing a note I hope  Eric

Theo Kleynhans wrote:Hi Guys

Yesterday I had a chance for my reed speed model.

It was unfortunately not a happy ending.

I think the engine was a bit lean, so it did not unwind in the air. So it was a bit slow. But the plane actually still kept the lines tight.

But I did not have any UP. Do not know why?? So after approximately 7 laps, I hit the deck.

Here are the remains:


I will see if I can put it back together today or tomorrow.

Theo

Sadly, my own Reed Speed models don't offer much in the way of lifespan either. If you have epoxy and glass tape you can fix anything!

At least you guys have flown yours.. that's more than I can say.

roddie wrote:At least you guys have flown yours.. that's more than I can say.

Same here. I haven't even benched the engine since switching to bladder...

Phil

I AM DONE !! 2 hours of engine work today/ not including yesterday / and it is cold and I am done (for now) ....   Video coming Getback

The most important thing I've learned in regards to this contest is VIDEO EVERY FLIGHT IF POSSIBLE! Even the "test flights", you never know when it might be your last. My staggerwing only got five flights but I filmed every one so I have an official flight for the contest.

Jim

Jim , Here is my video man I don't think my plane had a chance ... Up and onward Eric

Sounds like it was hauling ass. The engine was running great. Did it come in on you and lose line tension? That happens a lot with these. Unfortunately part of what makes them fly fast also makes them uncontrollable until they get that first lat behind them. I hope you can get it back together.
Good luck.
Rusty

My Nemesis is back together, ready for tomorrow to try again. Hope it will be a better result.

Here are some fixing pics:






Theo

Rusty , I had control and as before once you give it some down to level out it want recover and its ground pounding time . I reset the throw for less control ... I don't know if I will put it back or not at this time , maybe if I could get one round on it would be able to recover ??? Theo your plane came back together nicely . Good luck Buddy , Eric

Sounds tail heavy. Add nose weight or a spacer to move the engine forward. Balancing ON the leading edge is a safe bet that will fly fine but be somewhat sluggish to respond.

Phil

I feel your pain. This is what two flights will get you. I heard from Gus the I.A., next time this flies it will be pulled by the traveling engine.

JPvelo wrote:I feel your pain. This is what two flights will get you. I heard from Gus the I.A., next time this flies it will be pulled by the traveling engine.

Hang onto your socks with a TD in front of that!

Phil

It's amazing how well shattered wood fits back together with more precision than you could ever cut it. Slow CA or epoxy. I'm feeling better about my re-kitted Osprey all the time. And the old Copeland Skyray may see the sun again some day too. Luckily I have not busted my speed Mustang... Oh good lord, did I really just say that! Lol

I'd been mentioning how I haven't seriously wrecked a plane in two years shortly before I demolished both of the above within 3 weeks of each other.

Reckin' Rusty

What exactly is happening here? I'm totally baffled by what I see. From reading, I've read reports of no line tension or the plane is coming in. Is this happening on launch? I can't stress enough to over do your tip weight. It will solve the majority of the problems of line tension and torque roll. Forget about flying the other direction. It's not needed nor required to fly. Depending on what hand you are that can confuse you even more and it seems that the majority of flyers have a tendency to favor flying in the direction we fly in. 3/4 oz.- 1 oz. of tip weight in a 1/2A plane is not unheard of. Tip weight can be removed as needed.  Always start the maiden flight by dumbing down the controls.  Use less and add as needed. Having a sub rudder works, typically this works better on larger planes. Don't concern yourself with weight on a speed plane. A heavier plane flies better not to mention has more momentum. Build your planes on the nose heavy side. Typically in 1/2A they're going to come out nose heavy regardless. Using a single gear wire with the gear bent over to one side which automatically places the outboard tip on the ground is highly recommended. If you have a single gear wire, don't try and correct by launching the plane pointed outboard. Keep the plane tangent to the circle. Place the outboard wingtip on the ground. By the time the tip raises to level, the plane will be airborne. Obviously this can't be done with a two wheel gear and this methodology is not required. The pilot should have his arm fully extended out in front of them. When the signal is given to launch, the pilot needs to RUN BACK and in the direction of the plane . In other words your running back in a sweeping arc. Your not dragging the plane back but rather snatching it up and off the ground to prevent it from coming in at you.

        I've witnessed many times a pilot will get the plane into the air only to have the plane going straight up into a wingover. These planes will not recover from a pullout so kiss it goodbye. You may save it hopefully, but it's going to be a real short staining experience. If the engine isn't sounding up to par, don't launch it. Set your needle with the plane's nose pointed slightly up and to the right. Don't lean it too much on launch due to when the plane is launched, it will quit immediately. This is recognizable with tanks, so richening on launch is required and going in on the needle as needed on future flights. My hats are off to you fellows for your patience and persistence. I just don't like to see the carnage. Ken

Those are good tips Ken.. especially the running "back".. which I couldn't visualize at first but it's like; never giving the airplane a chance to get "behind" you "heading-in" before it picks up enough speed to get decent line tension. I'm thinking there is a natural tendency to whip.. or at least "lead" the model at launch, which probably exacerbates loss of control.

My Rare Bear's engine was finicky on my few attempts in the first contest. I hadn't run it enough on the bench beforehand either. It was actually a blessing that it never got off the ground. When building it, I didn't concern myself too much with weight.. (I have a sweet tooth   ) but seriously.. the model weighs 7.2oz. I went overkill with tip-weight; using .010" sheet Brass tips.. top and bottom.




Although I cannot vouch for it's "crash-worthiness".. I designed the fuse to utilize 1/4" square spruce rails, extending from the firewall back to the wing's T/E along with conventional doublers of 1/32" plywood. This adds strength beyond the doublers.. and the balsa canopy and belly contours can be added afterward. Your engine mount would be the last thing to break. The engine bearers are cherrywood.

Theo Kleynhans wrote:Hi Guys


But I did not have any UP. Do not know why?? So after approximately 7 laps, I hit the deck.

Theo

Theo,

A couple of thoughts. First, I don't see any support for the pushrod mid-span. It may be flexing? Try cutting off the back of a small safety pin and threading the pushrod through the loop, and gluing the pin about half way between the bellcrank and the control horn.

Also, that seems like a VERY small elevator. Are you sure it's large enough to give you sufficient control authority?

The Flexible Mark

Hi Mark, thanks for the info.

After getting to the field on Saturday to fly the Nemesis again, Keith Renecle took a look at my plane before we started, and he also saw the pushrod with no support. He then showed me how it bends by holding the elevator and moving the bellcrank. That was definately the problem with the first run. I took a needle and included a support mid way, and it worked perfectly.

The elevator was enough, it handled quite easily. But the wind was terrible. I had 20 - 25km/h winds. Not a joke on a half A plane. But I got a flight in for the competion.

Theo

Congratulations Theo! ( and a good spot by Mark/Keith) This is an area that I've been known to overlook on my models too.

Yeah I was reading that and thought Maybe that is why I am not getting recovery from down just try and level off . was thinking not enough air speed , but it damn near jumps into the air and no loose lines . Have not put it back together still smoking it over % of pain kindy gets to me with all the effort put into such a short flight:roll: I have cleaned the engine (flushed out that is) Eric

getback wrote:Yeah I was reading that and thought Maybe that is why I am not getting recovery from down just try and level off . was thinking not enough air speed , but it damn near jumps into the air and no loose lines . Have not put it back together still smoking it over % of pain kindy gets to me with all the effort put into such a short flight:roll: I have cleaned the engine (flushed out that is)  Eric  

That could be Eric.. it actually makes sense if you didn't add a support. You also have a bend there.. so I would definitely add a support. Did you fly it with the pushrod in that hole in the horn shown in this photo? I'd try the one farthest from the hinge-line for less sensitivity.