This somewhat bizarre-looking contraption constitutes the input feeder. Each
of the rubber wheels is individually sprung (by springs in the vertical tubes)
to allow for some slight out-of-true running of the roller, which was difficult
to avoid given the limited fabrication methods available to us when the project
was started. We've acquired some better tools since then, and would probably
use something much simpler if we were doing it again.
Brass couplings were made to adapt the mottley collection of roller
shaft sizes to a uniform 3/8", that size being chosen to match a collection
of small ball bearings that were on hand (from an IBM 26 card punch, if
you're wondering). The bearings are held in mountings cut from aluminium
bar and bolted onto the frame, one of which can be seen at the front.