Hi Fellas Modelers,
I have a 40 size canard wind from RICHMODEL (better known as the long-ez) after having it in a storage for a long time, I have finally finished. Nevertheless, I cannot get the CG right. I am aware of the flying features of this plane, but is been very difficult to balance it. I haven't done properly yet, according to the manual it should be located between 430mm starting from the leading edge of the nose wing aft the plane...please look at the manual picture.

Has anyone balance a plane like this before? tips are welcome..!!
Thanks
Carlos

That looks about right. You want the canard wing to stall first. On ALL tricycle gear planes they should balance just slightly in front of the main gear.

Hi DUBUCMAN
I don't have that model, but I have built two 46 size Canards with pusher engines, of my own design. Your CG looks about right. I always had to use lead ballast at the very front to get the CG correct. Eventually I changed the lead ballast to using two batteries and switches, mounted at the very front of the plane, which increase the reliability of the system. Make certain you use a pusher prop and that it is mounted correct. I saw a plane just like yours get totaled because the special pusher prop was mounted wrong. Also, my engine always overheated on the ground, but never in the air. Do all of your tuning using a "standard identical prop" and then switch to the pusher prop for flights. I actually saw fuel boiling in the carburetor of my engine while I was tuning it; that is how I learned that the engine would overheat in a pusher application. To my knowledge, I am the only person that has ever mentioned this (pusher engine overheats on the ground) in this forum, and with that, I let you to decide what to do about it.

Thanks guys..!!
That is exactly where is balancing right now, about an inch forward from the main landing gear. Just to make sure does that means is good..?

Hi DUBUCMAN
Please balance it according to the instructions in your kit. Do not make the balance point with reference to the landing gear. It is not the same thing. It is like putting the cart before the horse. Of course, that can further confuse you. Just follow the instructions, please.

Ok...I will.
thanks

Hi Carlos,

What are you using for balancing the plane?
How are you doing it?

I just put the weights that came with the plane, at the nose as it is indicated on the manual. I haven't add any extra weight yet.

Hello, I am building a canard glider of my own design. I thought such a thing does not exist, untill I read your post. Gliders are a little different than powered planes, but I have someideas. The simplest way to find center of gravity is drop the plane from maybe 8 feet or so unto a cusion and the nose should drop first. But the nose should not drop to much. A glider will lose a lot of altitude with the nose being too heavy, but I think a powered plane will not have this problem as much as a glider. If you are off center of gravity ina powered model it would be better to be forward, then move back in small increments untill correct attitude is found. I have a nitro1.2 Spitfier and with the COG too far back on it's maiden flight is was something just to get it down in one peice.

http://adamone.rchomepage.com/cg_canard.htm

Try this...worked for me.

Scott

I meant: what kind of balancing machine or rig are you using for determining the actual location of the CG?
How do you support the plane for balancing?

I am using the Great Planes C.G. machine, so far I have done with plane in the normal position (upside up) because is like a center wing, it is not high wing neither low wing. The manual does not mention anything about doing it upside down, so I assume that I doing it the right way. Does it sounds right to you..?

Yes, that sounds right, if the plane does not drop to nose or tail, but remains stable in balance.

The CG shown on the manual looks right to me, no reason to deviate from it I'd say.
It would likely be much easier and produce a lighter plane if you used electric power on the Long-EZ. The problem with glow is that you have the heavy engine right at the back and nothing of any significant mass ahead of the CG. This means that you will inevitably have to pile lots of weight in the nose. The real plane of course has a pilot up there to provide 'ballast'. With electric on the other hand the motor is relatively light and the battery can be located forward removing any requirement to add additional weight.

Steve