I think this gives you a very sturdy and rigid connection, unless you have play between pinnion and rack. You may want to think a little about the pinion diameter (speed vs. resolution).
May be its an idea to put a ball bearing (or two) at the other side of the rack, so the rack is between the pinion (adjustable by long holes for the stepper) and the ball bearing(s).
May be its an idea to put a ball bearing (or two) at the other side of the rack, so the rack is between the pinion (adjustable by long holes for the stepper) and the ball bearing(s).