RCU Forums - Need help with full flying canard

You'll need some nice bearings in the fuselage sides and either heavy wire or small sized steel tubing to form the axle.

If you go for music wire I'd suggest 1/4 inch to minimize the bending that will take place with surfaces of that size. If you go for tubing try to find some 3/8 to 1/2 diameter steel tubing that has at least a 1/32 inch wall thickness since it'll probably be soft steel. You can get away with 1/32 thickness if it's a heat treated alloy with a bit more spring to it. If you want to try using model shop brass then I recomend three telescoping sizes starting with something like 7/16 and down. Clean well with fine sandpaper and glue together with epoxy or thin CA to bond the tubes thoroughly their entire lengths. DO NOT solder in this case as the heat of the soldering will anneal the work hardening in the brass and it'll bend much too easily. Carbon tubing of about 3/8 to 1/2 diamether would also be nice but be sure it has a thick wall in the order of 1/16.

The bearings can be brass tubing bushes for the metal axle options. For the carbon tube I'd recomment glueing a brass bearing ring to the tube and then use short lengths of the next size up as outer bushes in the fuselage sides so the carbon tube doesn't wear against the metal. If you can find nylon or teflon tubing then that may make nice bearning bushes as well. But in any case the bearings in the fuselage should be at least 1/4 wide for low wear and point loading. Do not try to use sheet material for the fuselage bearings. The loads on the edges of the sheet will result in either crush damage or accelerated wear.

The pivot of the axle line must be very close to the 25% Mean Aerodynamic Chord of the surfaces. Do not try to cheat on this one or your servos will be overpowered by the flight induced pitch loads. For surfaces of that size you will also probably need a jumbo servo or certainly something larger than the basic cheapies.

Good luck.