I have the Sig Extra 300XS, and have it all done except for the engine, which I am ready to get. I want to get the plane to balance on CG without any added weight, as I understand they are already heavy from the start. Does anyone know what engine and muffler combo will help get this done? I really don't want to add any weight to the nose or tail if it can be avoided.

Thanks Bob

I would always prefer a nose-heavy plane, as opposed to tail-heavy. Nose-heavy is so much easier to fix.

That being said, I think your looking at a 160--2.1 2-stroke engine to balance it. I'd lean towards bigger and heavier, if your trying to avoid adding lead to the nose for balance.

I had a ST3000 on mine, and it balanced just a snitch nose-heavy. If memory serves, it only took about 1/2oz of lead in the tail to balance it where I wanted to fly. I could have just moved the battery, but I didn't want to go to the trouble.

I think that if you put a lightweight engine on it, like a Saito 150 or a 120 2-stroke--your going to be tail heavy, and cussing yourself. I'd go for the heavier/bigger engine, and use it later on a 27% plane. A Moki 2.10 will horse that Sig 300XS around like a rag doll, you'll just have to be easy on that left stick. Then, when you crash the Sig or get sick of the way it flies, you can use the big Moki on a larger plane later.

What do you mean sick of the way it flys? I have heard that other than being a heavy plane, it flys great, just not a 3d machine, which at this point I don't need.

I had a OS 1.60FX with two 1500mah batteries mounted in the nose and still had to add several ounces to the nose. I think any of the 40cc gassers would probably solve this. Mine was a touch on the heavy side at 14lbs but it was a sweet plane. Someone who wanted to do 3D and hang it on the prop whould surely need more muscle, but it did all I wanted. I think the new Dave Patrick 1.80 copy of the Moki would be perfect. It might not fit completly in the cowl like the OS because its a bigger engine and the OS just fit side mounting it. It was my first plane bigger than a .40 size and take-off and landing was like a trainer. Very easy.

Dan

Bob,

I had one with a Brison 2.4 in it. All I can say is WOW ! I loved it ! I ultimately sold it to a guy in Vegas. He wanted it so bad he even payed me to crate it up (special box I made).

Here is my Extra...

http://www.caswellplating.com/restgal/other_projs.htm

Scroll down past the heli.

I did not have to add any extra nose weight and mine was 14.5lbs.

Hope this helps you.

CJ

I had one with Brison 2.4 until I flew it into the ground. I liked it so much that I bought another one and I am going to put a Brison 3.2 on it.

So, from what I am reading here, around a 3 - 3 1/2 pound engine should be about right.
Am I correct? If thats the case, what does anyone think about the BCMA-SPE40? It's
a gasser, 40cc, and weight is just over 3 pounds. [link=http://www.bcmaengines.com/]http://www.bcmaengines.com/[/link] click BCMA-SPE and scroll down. The specs. look good, and the price looks great.

Thanks Bob

Bob,
I've got a Saito 1.80 in mine and the CG is dead on without any weight added. I used a pull-pull to get it there but it balanced perfect.

What do you mean pull pull? The rudder is already set up that way. You mean you went pull pull on the elevators as well?

Thanks Bob

I had to go back and look but you're absolutely correct. It was original setup with a pull-pull rudder. Sorry, mine is a few years old now. It's been a while since I put the thing together.

Thank you for the reply. I went with the Futaba 9252 servos instead of the Hitec 5645 that saves about a half ounce in the tail and a little over an ounce overall. I looked and the Satio is 31.4 ounces no muffler and the OS 1.60FX is 32.8 ounces. So I think I will be able to use the OS with little or no additional weight for balance, Which is what I am after.

Thanks Bob