I made this remix because the 2mm holes were binding while pulling filament through. PTFE really helps with that. Cut small sections of ptfe tube to use as guides. The hole diameter is 4.35mm (my ptfe tube measured 4.1mm O.D. and fit snugly). Technically, CA Glue won't adhere to teflon but I found that roughing up the end with sandpaper and using a small drop before putting the tube in the ends help to hold it in place.
Please see the original thing for parts and instructions.