Quote Originally Posted by TopJimmyCooks View Post
...quick search shows 2mm ID 3mm OD pfte is available. Maybe a good way to go, possibly even reversable once installed.
TJC - see if you have any somewhat used BIC pens laying around. The ink tube is pretty close to 3mm OD, 2mm ID. Some people have used lengths of spent ink tubes as a liner in the 3mm-native Greg's Wade extruder body provided by MakerFarm. I've seem some pens with tubes that are too narrow - especially giveaway-type pens that are likely trying to go cheap on the amount of ink.