I always had problems with the filament to slip over the side of my spool and curl around the holder. This leading to aborted prints. Therefore I designed this clip on spool extenders for OrbiTech spools which fit in the existing holes. The model is created with the included OpenSCAD script which is not fully parametric yet as I do not know if there are similar holes on other spools. But if anyone can send me measurements of other spools I can adopt the script.Simply print two left and two right extenders (or the full plate) and clip them on your spool. Enjoy! ;) The attached STLs work best with layers of 0.5 with 1.3 width_over_thickness.