This is a remix of the Bambu Lab spool extender, designed by yul. Thank you for designing and sharing this.
When changing large spools regularly the original tended to snap, when a rather small force is exerted upwards, I added a bracket that bolts the extension to the original spool holder.
The model has been cleaned up a bit and fits now snuggly into the OEM spool holder.
I have tested 3kg spools with 110mm width for a couple of weeks now.
The TLDR-version:
You'll need one M3 hexnut and one M3x10 screw. M3x12 and M3x16 work as well.