Posts: 521
Threads: 72
Joined: Jul 2007
I've successfully repaired the drive wheels in desktop calc tape readers using heat-shrink tubing.
Take out the drive wheel (or tape drive assembly). Scrape off all the remains of the disintegrating drive wheel rubber. Get the bare metal wheel as CLEAN AS POSSIBLE.
Now hit your local electronics supply or Radio Shack. Find the smallest heat shrink tubing that just fits over the drive wheel. Back home, use a razor blade or very sharp knife to cut a piece just a millimeter or so less wide than the drive wheel. Slip it over the drive wheel and use a match or heat gun to shrink it.
Others have used 2 or 3 rubber O-rings of the proper size. These will probably result in a quieter drive, but the heat shrink tubing is easier to find.
Posts: 464
Threads: 10
Joined: Jan 2005
Hi,
If you don't succeed in getting the part, I've put online a small procedure to rebuild it: here.
After you get your rubber wheel ready, voidware has a documented procedure to take apart and rebuild your Hp-85: here.
Greetings from France!
Etienne
Posts: 669
Threads: 63
Joined: Dec 2009
For capstan repair/replacement info check
http://www.series80.org/Articles/capstan-repair.html
For a detailed discussion on how to take apart an HP-85 to get to the capstan (and a novel way to attach heat-shrink tubing to the capstan), check http://www.voidware.com/calcs/hp85rep.htm
**vp
For info on HP-85 related items check the links section at http://www.series80.org/#links