The only airplane I have with nyrods needs a trim every first flight of the day - a wild trim!!!
other wise the airplane is in a wild down elevator, some times the servo is at the end of the trim and its still in down elevator so link need to be moved and moved again later during the day when they come back to their initial size.
all other airplanes I use sullivan composite rods and trim it only at the maiden and thats it.
I use the method CG retired described with the drill and make sure the tip of the metal rod is rounded its very important.

Alex