I would like to build my second chrysalis 2m and was wondering if anyone has ever made a "narrow" fuselage for it.

I would like to make it just wide enough to fit two tandem seated HS-60s and a size-challenged FMA rx. Any recomendations? I also plan to give it the "Treatment" on CASL's Reel Balls equipped winches. I have read and plan to follow the wing reinforcement procedures outlined in Ask Joe & Don, but any further recommendations will be appreciated.

From : Don Stackhouse

The only tricky part about narrowing the fuselage will be the shapes of the top edges of F2. The curve of the top of F2 will have to be shrunk horizontally, but its height in the middle kept the same. It's height at the outer edges should match the fuselage, as should F3. You will also need to make F4 narrower, but only by about half the percentage that you narrowed F3. Of course you should leave the two bulkheads at the tail unchanged.

For serious winch launching, in addition to the .007"x 1/2" carbon on the outside of the lower spar cap and .014" x 1/2" carbon on top of the upper spar cap, and making absolutely sure you have a good bond between the carbon and the spar caps and between the spar caps and the shear webs (strapping the whole thing together with Kevlar thread wouldn't hurt), you will need to make sure the wing and tail are stiff enough to avoid flutter, in addition to adequately strong in bending.

It might be a good idea to run some 1/4" wide strips of .007 carbon on both sides of the stabs from root to tip in front of the hinge line, and from the root leading edge to the tip.

You can stiffen the wing by fitting little trapezoidal diagonal ribs in a zig-zag between the pairs of laser-cut ribs, between the main spar and the leading edge, and between the main spar and the rear spar. This makes the wing structurally equivalent to a geodesic structure, but without requiring you to cut a bunch of ribs to exact airfoil shapes. Shear-webbing the rear spar would also help.

Don Stackhouse
DJ Aerotech