The low friction spool holder I already use for several Ultimakers and I liked the idea of the internal spool holder for the Anycubic Kossel. Therefore I combined both by using the two parts I designed.I use the "M8" thread version of the low friction spool holder. The top and bottom part and the three parts of the Anycubic holder are mounted together by using 6 x M3 screws and nuts - I think the lenght is 16 mm. Instead of modifying the three parts of internal spool holder before printing, I assembled them with my parts and just use 8 mm drill to remove the parts blocking the space for the thread.
https://www.thingiverse.com/thing:2301167 : 3 x brazo.stl
https://www.thingiverse.com/thing:235925 : 1 x 608_spacer.stl
1 x 608_core1.stl
1 x 608_core2.stl
1 x 608_nut.stl
6 x M3 16 mm
6 x M3 nut
1 x M8 thread (120 mm?)
3 x M8 nut
2 x 608 bearings
I noticed that adding a short bowden tube in front of the feeder decrease the chance of filament falling from the spool ...