Originally Posted by SDplinker
Brian we aren't on the same page. I will try to do a video mockup to explain. Due to the design is that why you slide in on from the eye piece side rather than the objective side? My goal wouldn't be to have the tube printed. I'd use off the shelf CF or thin aluminum in some readily available size.
Ah right, gotcha - so the tube would need to be something like 55mm + ID to go over the objective bell, with a boss to fit onto the obj bell and a marked ring to go at the other end. You'd probably need a raised pointer making as well.
Have a look around for some stock CF or ally tube and let me know what sizes you can get around the 55mm mark (or larger if you like) and I'll design up the boss and number plate.