I've used these 4-40 Dubro couplers, nicked up with a dremel cut off wheel for the glue to grab to:

http://www3.towerhobbies.com/cgi-bin...?&I=LXD924&P=7

One on each end of a CF rod. Rod ID needs to be close to the same diameter as the coupler. Then glued in with Flash Black type of CA:

http://www.horizonhobby.com/Products...source=froogle

This type of CA doesn't harden quickly inside the rods, so I usually leave them for a few hours or overnight to harden. Accelerator doesn't seem to get far down into the rod and it's mostly airtight in there.

The black CF rods can split lengthwise so you need to sleeve the rod ends to keep them from spliting under side loads. I usually use heat shrink, but others have used brass or aluminum tubing.

I'm about to install a rudder pushrod in a scratch build jet using this method. I also used these on two Cermark MB-339's on rudder & elevator.