Found a simple but nice solution for a spoolholder designed by FedorSosnin.
My 105zz bearings didn't fit this design so i designed a spool holder that fits my bearings and where the weight is distributed over 4 bearings, 2 per part.
(A set of 10 MR105ZZ (5x10x4mm) bearings costs €1 on Aliexpress
Spool rolls much smoother which ensures better alignment with the extruder.
Edit: An additional filament guide will ensure even better alignment with the extruder. This is a remix of the filament guide designed by Holspeed. No bolts/nuts are needed, only two 3dprinted parts and one 105zz bearing. Supports (>80°) are used for the filament guide.
Filament aligns better with the extruder
Additional filament guide (helpfull for the heavier spools)