i idea i brought to life. you turn the knob to tighten , then push knob into body with pegs on knob lining up with holes in body. this holds the tube from unwinding. the pressure to unwind helps to hold the pegs in place.

the roller has teeth in between the 2 sides to keep the 2 sides from moving during print. it is printed vertically.

the peg/holes are tight until u work them awhile. work then turn to next hole then work your way around the holes.