Here's a simple little lathe project that anyone can do with a minimum of fuss, and can save a lot of money.
This is the upper wheel that was made from a $20 8"x2" sintered caster from HF -- it has a good set of roller bearing and works perfect for these projects
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/HF_Ad.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/HF_Caster_Parts.jpg)
Remove the bearing cage on the caster and machine, part, drill and tap a madrel to length
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/Image01.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/Drilling_Mandrel.jpg)
Caster mounted and the first cuts are made
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/First_Cut.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/Finish_Cut.jpg)
Using the lathe, the caster was sanded with 600 then 1000 grit paper, and finshed with rubbing and polishing compound for a smooth finish
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/English_Wheel_2.jpg)
(http://i357.photobucket.com/albums/oo18/goodfellow_2004/E-Wheel/English_Wheel-.jpg)
These things are not as hard as commercial e-wheel uppers, but for 20 bucks they can be easily replaced every few years.