Shaft coupling set: 5 to 5, 5 to 6 and 5 to 8 mm. Use 0.4 mm print-head, ABS/PC, 0.15 mm layers, supports for 80 degree overhanging surfaces, print multiple parts. After 3D printing remove supports with the knife, use 2xM3 nuts and 2xM3x12 screws to fix to shafts. Enjoy!