Wie gut sind die neuen China Kugelumlaufspindeln?!? Wie erkenne ich die Qualitätsunterschiede???

As requested by my Facebook group, the Hobby CNC community, I show a small selection of the ball screws I use for my CNC projects. I go into the advantages and disadvantages of each type and also check the concentricity and quality of the various spindles and recirculating ball nuts. The spindles are of course also suitable for 3D printers, lasers, portal milling machines...