I need a longer Filament arm for this holder. There are three variants of the longer arm. One with M6 thread for PC4-M6 Festo fitting, second with thread for PC4-01 fitting and third with bare hole for PC4-01 fitting.
The threaded parts are better to print at lower layer height (0.1 - 0.15 mm) to get smooth threads and holes. The third variant with bare holes prints OK at 0.3 mm layer height.
Little sanding of rough layer at rounded mount area of the stand was necessary for nice fit of the arm. If using the bare hole variant use the PC4-01 fitting to cut the thread in the hole itself. Safe the arm in place with a M4 bolt and nut.