Spinning Wheels on Star-Trek

The other day I was watching season two of Star Trek: The Next Generation. One episode ("Up the Long Ladder") included, to my surprise, spinning wheels belonging to a group of Luddites whose home planet is about to explode, or otherwise be destroyed, and who have taken refuge on the Enterprise. Shown were several Saxony-type wheels and a skein winder. Not shown was anyone actually spinning, but in once scene a wheel is turning.