5.3 Coupling: Loose coupling

The coupling is considered to be loose when the motor's shaft is rotating but the disk holder is not.

Two screws are used to secure the coupling onto both shafts.

If the coupling is rotating with the motor while the disk holder is not rotating, the top screw is loose.

If the coupling is not rotating while the motor's shaft is rotating, the bottom screw is loose.

Using an allen key, hand-tighten the loose screw.

The screw is considered to be tight enough if rotating the coupling causes it to rotate both shafts.

If the coupling is still loose, move on to step 4 and do not go on to over-tighten the screw lest it gets stuck.

Over-tightening one screw will cause the other screw to be unable to be screwed in fully due to the design of the coupling. Hence, if the coupling is still loose despite the screws being fully screwed in, remove and re-tighten both screws.

Do not over-tighten any screws as the alternative screw would not be screwed in properly.

Do not apply excessive normal load on the disk as it would result in a excessive torque which the motor may not be able to cope with. This would cause the bottom half of the coupling to be loose as the motor fails to transmit the excess torque required onto the disk holder.

The video shows the process of over-tightening a screw. The distinctive sound made is an indication to STOP further tightening of the screw.