New version with upper limits removed and smoother threading.

If you, like me, hate dangling spool on the original holder, here is the solution.

A universal threaded spool holder, simply fitting on the existing spool axe.

Nut's neck length can be set to adapt to any spool width.

Included optional  washer, adding a slight gap to avoid holder rubbing on the stand.

Can be printed using any filament type. No support needed (check plate setup picture) except for Fixed Plugs part : 

support paint the plugs, and set support to Tree, checking only Support critical regions only.

Now fully parametric to be set to any desired size.

Standard values :

A1 : diameter 24mm, Len 71.5mm

A1 Mini : diameter 17.5mm, Len 68mm

Some limit values apply :

Len must be ≥ 45mm

Diam must be ≥ 5mm and ≤ 25mm

Neck must be ≥ 0.1mm

Installation :

1. Simply interlock the two spool holder parts on the spool axe, adding the two washer parts before final pressing