Spool holder for 3 kg spools
The spool holder on my MK4S printer is only suitable for spools of 1 kg filament. While these are fine for small prints, for larger prints it is preferable to use larger spools.
Initially I used two support cradles where each to the rims of the spool runs on two roller bearings. This had some problems in that it tended to bind and then the spool could be pulled off the bearings. After this caused the failure of an overnight print job I wanted a proper spool holder.
Not being satisfied by designs I could find online I designed my own, for spools up to 3 kg.