I just created an easy way to thread Teflon (PTFE) tube.
Turn the end of a M4 ~0.7 bolt so that it fits inside the tube. thread your die onto the bolt, backward (so the taper faces out) clamp into a vise and push the tube on and hold without crushing. Now turn the tap off the bolt onto the tube gently, backing often
(Also, I will be adding my extrude design, Cog hobber and some more work on the tabloid soon.)
To use the hobbing tool, mount it as if it is a tool post, put the cog on a shaft and a coarse tap in the lathe chuck, something like 3/6 ~16 or 1/2 ~ 13, Imperial coarse tend to be bigger threads than metric of similar diameter.