Insert 608 radial bearings from the Mc-Master Carr online store.
Determine the dimension for the bearing, Then draw a polygon, add dimension and add constraints.
ps. for the constraints choose ( Horizontal / vertical)
Choose offset from sketch select the outer circle and draw 3mm offset.
Repeat the same thing for the polygon
Choose a circular pattern from sketch and select the polygon and select the (0,0) as the centre pointe and choose the number of repeats that you want.
Choose 3 points-ARC from sketch
Choose the circular pattern repeat step - 05 for the ARC.
Stop sketch and select Extrude, Then select the part that you want to Extrude.