2020 extrusion end cap with filament guide

End caps to fit onto 2020 extrusion. Specifically, these are meant for the uprights of an Eclips3D, which are closed on two sides. There is a variant which has a guide through which you can pass the filament, optionally via a piece of PTFE tube. It may be a tight fit - if so, file the hole out slightly. Note that you will need to print two of the caps in mirror image, which can be done easily in Repetier host.

EDIT:
Added another version which allows you to tighten the holder around the PTFE