Lock motor coupler

If you need to lock the spring efect of z axis coupler in ou Anet A8 this is the thing, it's very simple and does the job.
You don't need to dissasemble nothing, because it's easy to put through the 8mm rod and over the coupler.

Hardware need:
4 units of 3mm nut
4 units of 3mm x 16mm screw

I don't know if it improves the printing or not, but if you are using Marlin's Auto Bed Level the Z Axis is in constant move so this disables the spring efect and probably improve precision.