Here is the end feed flyshuttle I have been working on for a bit. It has a set of wheels on the underbelly, a tightning mechanism and a home made pirn loaded with 2-ply wool.
Picture showing the pirn mounting hardware. Knock down fitting (cam and bolt) and brass insert. The cam has an arrow that points to the insertion point in the shuttle for loading and unloading with no guess work. Tightened with a screw driver. The pirn will hold 10 yards of 2 ply wool yarn easily.
Some video (7 secs) demonstrating the shuttle in motion across a hardwood floor. As we know a hardwood floor is not perfectly smooth. ;)
http://www.youtube.com/watch?v=FStpursYeuU
Testing pirn spooling with different thread weight.
http://www.youtube.com/watch?v=1C-wlVvpdFw
Enjoy. :)