Inner diameter of 0.24 mm are drawn largerBall bearings must be pressed fitWhen installing make sure that you so screw the M3 screw straight as possible. I have the ball bearing used as a guide. When finished Mounted then press coil holder purely in standard as the approximately (see Picture_04) is measured 50 mm. (Maybe still need the pages (Bauteil1) can easily be reduced) Then look at whether filament coil moves in track. If not, remains to be press Next page down.