I put together this pirn winder over the course of the winter, kind of experimenting along the way and having a look at various winding mechanisms on Weavolution and other websites. I have plans to built a larger spool winder for my spool rack. I will also be turning a bunch of spools on the laith sometime soon.
I'm surprised had how much more yarn can be packed on a pirn when it's wound taught with a winder.
A little video here of the action. ;)
http://www.youtube.com/watch?v=UVsSWdEIIFk
Enjoy :)