Crystal Style Retractable Ceiling Fan Fanaway Ceiling Fan,Foldable Ceiling Fan,Crystal Ceiling Fan With Foldable Blades,Fan With Retractable Blades JIANGMEN ESCLIGHTING TECHNOLOGY LIMITED , https://www.esclightingfan.com The universal joint cross pin (Fig. 1) has high processing precision requirements, and the end face verticality and symmetry requirements are strict, and it is difficult to process on the cylindrical grinding machine. To this end, we designed and manufactured a special fixture for grinding the cross pin end face on the M7140 surface grinder. The end face symmetry is guaranteed to be no more than 0.009 mm and the perpendicularity is less than 0.008 mm.