looking for that killer winter project. i would like to build a canard sailplane. any help on balance, fuselage length,... would be helpful. also considering using the canards as primary control sufaces i.e. move like flaperons. does this work or is there to much inertia to overcome from the wings? this will be a 2.5m to 3m plane.

There is one person who is considered the authority on designing canard type models, Andy Lennon. He did a series of articles in one of the major modeling magazines, Model Airplane News I think, a few years ago. He wrote a book called "Canard : A Revolution in Flight" that has a lot of good informatioin. I believe that you can order a reprint of his articles from the magazine. There is a list of books on my web page. You can click on the title of the book to get a synopsis and even order it online.

Why do you want a canard sailplane? The canard configuration produces a lower glide ratio and higher sink rate than a conventional tail-in-the-rear design, all else being the same. The canard arrangement makes it unlikely that the main wing will stall and it is cool lookig - but it won't be a 'killer' flying sailplane. One hint is the lack of canard sailplanes flying today. That isn't because no one has thought of them.
What do you want to get from your new plane that you can't get from a proven design?If you want the best flying plane in the area you might reconsider. If you want something that looks cool and flies so so then the canard may do it.

The only canard sailplane of which I am aware is the Rutan Solitaire.

I agree 100% with Jack Hyde. Canards have virtually no aerodynamic advantage, as far as I can determine, over the normal layout, and in addition, they have some serious practical shortcomings. Some people, whom I believe to have been a little misguided, seem to think that they will not stall. This thinking is based on having the tail stall before the wing, causing the nose to lower, and thus reducing the angle of attack of the wing, preventing it from stalling. The trouble with this is that if the wing cannot, at least, approach stall, landing and takeoff airspeed will be increased accordingly.

A airplane with the normal, tail-behind, layout can also be made virtually stall-proof simply by locating the CG well forward, and limiting elevator authority. This is a very common setup for R/C trainers, and is totally unsuited to serious aerobatics.

If you set up a canard airplane to have sufficient control authority to stall the wing, and use an aerobatic CG location, they perform almost exactly the same as normal airplanes. I built a small canard glider, as a research airplane for a canard pattern ship that I was designing, and found that it would spin and snap roll exactly the same as a normal airplane. I never built the pattern ship, because I realized that with so much weight so far rearward, it would break up very badly in a crash that would result in little damage to a normal (tractor) layout airplane. (If you are going to fly, you are going to crash - the only unknown is when.)

The only reason that I can see to build a canard is to get something that looks different. All other characteristics are, at best, no better, with the possible exception of knife-edge, which may be considerably better than with a tractor layout, since the center of lateral area tends to be closer to the CG.

In a canard aircraft, you want the canard to stall before the main wing stalls. This is why canards generally have a high AR, compared to the main wing. This provides stability by not allowing the aircraft to turn itself over (that is, having the main wing stall, while the canard is still providing upward force).

This is the opposite of what you want with a conventional tail. With a conventional tail, you want to make the main wing stall first. If the main wing stalls, the nose drops and you can (hopefully!) resume normal flight.

So, for a canard sailplane, you will want a very high AR canard (higher than the wing AR). OR... you need to find some other way to get the canard to stall first.