This is a very quiet spoon holder due to the four bearings.
Four 16x8x5 bearings and an M8 threaded rod are required for complete assembly.
The holder is designed to be placed on a plane, such as on the roof of the 3D printer enclosure.
If the bearing does not fit, you can heat the polymer with a lighter. Heat it until the polymer softens and then insert the bearing.
However if your 3D printer is accurate the problem should not arise and the bearings should fit perfectly.
The author hasn't provided the model origin yet.