|Re: Ok someone explain this gummy wheel problem|
Message #3 Posted by Todd Garabedian (USA) on 8 Oct 2000, 7:24 a.m.,
in response to message #1 by Mike Davis
My understanding is that when HP developed their card reader back in the mid 1970s, the best material for use in the drive wheels of the card reader motor was a rubber derivative. Well, that rubber will oxidize over time and turn to a gummy mess. So, it's quite possible (and probably very likely) that an unused card reader would have it's drive wheels deteriorate. Oxidation is a process that doesn't discriminate between used and unused card readers!
Materials technology has progressed since then. As mentioned, Dave and a few others on this forum have described replacing those wheels with silicone-based materials that are much less prone to oxidation. Replacement wheels per se cannot be purchased anymore, but several ingenious collectors have found that certain O-rings, tubings, etc., match the required size quite well. Replacing the wheels is apparently a fairly straightforward process, although I've never done it myself.
Best of luck,