This is Omni-wheel which can make using cheap 3D printer and assemble easily without screws.
Parts
Body x 1
Sub wheel x 18
Metal shaft(0.8mm) x 18
(I verified with this: https:www.yodobashi.com/product/100000001003838285/)
Verified printe
UP mini2
CR-10S
How To Assembly
Print "body.stl" x 1 and "sub_wheel.stl" x 18 using 3d printer.
Cut the metal shaft to about 12.5mm.
Iert shafts to the hole of sub wheel.
Push the shaft and sub wheel to the all bearings of the body until you hear a click.
Demo
Note
If you print it with cheap printe such as ANYCUBIC and da-vinci, please choose "body_reprap.stl" and "sub_wheel_reprap.stl". Difference between those files is a groove size of the bearings. This is because the groove size will be smaller when you print it with some slicer such as Cura and XYZmaker Suite.