I almost fell over on this one. The build seems doable overall for someone with a metal chop saw and other tools.
http://www.homemadetools.net/forum/small-beltsander-lathe-attachment-rotary-tool-46381#post66331
Another nice build to add to this is the authors dremel lathe
http://www.homemadetools.net/forum/dremelathe-diy-woodworking-station-51175#post73876