Just having a bit of fun on a winter night here, tell me what you think...


I have Sig's Sukhoi ARF (the big green one) almost built.
I don't have an engine in it, and I'm passively wondering about two engines for it.
Observe....

Sig Sukhoi SU-31
13lbs - 8oz weight.
Specs call for 2.4 cu in gas engine.

Candidate Number One
ZDZ 50NG
3.4lbs all up
+25% displacement over Sig's spec
$585.00

Candidate Number Two
Zenoah G-45
4.63lbs all up
+15% displacement over Sig's spec
$0.00 dollars because I already own it.


In short: The ZDZ lightens up the airplane by roughly 10% over the G-45, and provides a 10% displacement increase over the G-45.
But it's six hundred freaking dollars. [:'(]

So by the numbers: Would you...?

[&:]

Sell the G-45 and buy this http://www.zrcgf.com/store/Details.c...=28&category=2

I'd use the engine I had and fly it. 99% of guys really couldn't tell the difference in the wing loading anyway.

Here's how it calcs out:

1152 square inches of wing.

It currently weighs 13lbs 8oz, so right now you have a wing loading of 27oz/sq ft. without a motor.

Add the weight of the ZDZ and you get a wing loading of 33.8oz/sq ft

Add the weight of the G45 and you get a wing loading of 36.26oz/sq ft

Thats a difference in the wing loading of 2.46oz/sq ft. Big deal. Put the G45 on it and save the $600 for a bigger airframe.

But now your talking about a >16 lb. Aerobatic plane with a G45.

The ZDZ NG50 is a lot more engine than a G45

You would most certainly notice the loading difference between the ZDZ and Zenoah. I few this particular plane in a few different variations and in each case the lighter one flew better than the heavier one. When the Sig Sukhoi was designed there was not as much attention paid to airfoils as there is now so the wing planform is not as good as it could have been. It actually flys best with a lightest engine that has the power to fly it.

The Zenoah G45 weighs about the same as the Zenoah G62

How much weight could you save by putting the G45 on ignition?

Well of course, lighter is always going to fly better. In a perfect world, he'd be using a Moki 2.10.

But he asked for opinions......... should he use the motor he's got or spend $600 on a new one? I personally wouldn't even fly it. Too small. I'd sell the engine and the airframe and put the cash into something larger. But if he doesn't want to sell the stuff right now, then mate 'em up and fly it until the cash situation improves. Not every plane in the world is a 3D monster. I think it will fly just fine for sport aerobatics. Even entry level IMAC.

Just my opinion. Not saying anyone else is wrong. I really think people worry too much about wing loading. It is what it is.

You'd save close to a pound putting a C-H ignition on the G45

Rcpilot,

I concur 100% with your last post.

Why not a DL50 if weight and $$$$ Is what the problem is....

Second thought: DL50 may be to large for the plane...[sm=confused.gif]

Personally I think people take wingloading too far sometimes on a big plane 35% or 40%, however on a small plane like this 3oz is a big difference, especially after you break 30 on a plane this size.

I had one of these with a converted skil 45 (maybe it was a 42 or 43 but somewhere in there) and it hauled butt but it was definately on the heavy side. I remember my first inverted flat spin scared me to death because I almost couldnt get out of it Outside of that I had a lot of fun with the plane, I just had to learn to land a bit quicker than I liked. Of course mine had been repaired so it was even heavier.

I would consider post 2.. or get your 45 lightened? I certainly would not go spend $600.

I would fly it on the G45. I had this same ARF, and it's a very good IMAC plane. I had a G38 on mine. It was under powered, and a tad heavy at 16 1/2 lbs. I had fun with it... I sold it to my buddy, and he is still flying it today. He loves it. I would guess the engine is 15 years old, and the ARF is 8 or 9 years old.

G-38, underpowered, a tad heavy. Possible two combined to create the underpowered problem?

That was then, this is now. LOL!!

Back in those days my other "hot rod" was an 18lb AeroPro Laser outfitted with a G62 (from Ralph), and 1/4 scale Hitec servos all around.
I even had a fancy kill switch from Bennett.

YeeHaw!!!