I wanted to mount an external spool to the side of my honeycomb riser using the GREEN AMS lite rotary holder. This give the external spool a little bit of back tension to keep it from unwinding freely. Its compatible with the PTFE tube guide that Chiu Kang has created here ( https://www.printables.com/model/584158-simplified-hex-spool-holder-with-ptfe-tube-guide/files). For ease, I have included  his PTFE tube guide STL file here. Should be able to print without support and use and m3 screw and nut to secure the base to the rod. 

You will need:

(2) m3 screws  ( I forgot the length, might be 8 or 10mm) 

(2) m3 nuts

(1) Green AMS lite rotary spool holder (https://us.store.bambulab.com/products/ams-lite-rotary-spool-holder)