I've got a flakey HP-67 card reader that I think has a clutch problem. I repaired the gummy wheel on this reader a few years back using "O" rings. They look fine, but the reader has real problems pulling a card through-- terrible squeaking noises and jerky card movement. I have tried adjusting the drive wheel offset but it seems to make little difference.
The pitch of the motor jumps higher when the card slows or stops, which I attribute to clutch slippage.
The worm gear slides easily off the motor shaft. Apparently the "clutch" is a rubber or plastic material inside the worm gear shaft that provides a friction fit to the motor shaft.
The obvious solution is a drop of adhesive, but that would eliminate the "clutch" action. On the other hand, unless the reader mechanism jammed solid, would this hurt anything?
Suggestions on a reasonable repair appreciated...