gee you were very lucky. You could try a setup I have on my 1/4 scale Cub.

I use fiberglass arrow shaft. Use the 4-40 rod but what you do is trill a 4-40 hole about 1 1/2 " back from the end of the shaft. Put a 90 degree bend in the 4-40 rod with about 1/2" on the bent end.

Next you take a piece of wooden dowl that will fit inside the shaft snuggly. dremel out a channel so that the 4-40 rod can recess into it.

You then put the bent end of the rod in through the hole in the shaft, then epoxy in the dowell.

Should solve your problem.

cheers
Peter