It is not completely necessary to machine-match the ends, if the ends are cut just short of the bottom of the trough, a small gap can exist because the gear does not touch the bottom, a short piece is used to straddle two lengths while fixing to keep the pitch identical, I usually use counter-sunk allen head, why the tapped holes by the way, if you are counter-sinking?
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.