The following warnings occurred:
Warning [2] Undefined array key 6252 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6254 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6256 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6258 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6259 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6262 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6270 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6295 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6302 - Line: 275 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 275 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined variable $thread - Line: 295 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 295 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Trying to access array offset on value of type null - Line: 295 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 295 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined variable $fid - Line: 295 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 295 errorHandler->error_callback
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6254 - Line: 331 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 331 errorHandler->error_callback
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 304 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6270 - Line: 331 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 331 errorHandler->error_callback
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 304 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined array key 6302 - Line: 331 - File: inc/plugins/threaded_mode.php PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php 331 errorHandler->error_callback
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 332 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 304 ThreadedMode::buildtree
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined variable $theme - Line: 3 - File: inc/plugins/threaded_mode.php(305) : eval()'d code PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php(305) : eval()'d code 3 errorHandler->error_callback
/inc/plugins/threaded_mode.php 305 eval
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Trying to access array offset on value of type null - Line: 3 - File: inc/plugins/threaded_mode.php(305) : eval()'d code PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php(305) : eval()'d code 3 errorHandler->error_callback
/inc/plugins/threaded_mode.php 305 eval
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined variable $theme - Line: 3 - File: inc/plugins/threaded_mode.php(305) : eval()'d code PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php(305) : eval()'d code 3 errorHandler->error_callback
/inc/plugins/threaded_mode.php 305 eval
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Trying to access array offset on value of type null - Line: 3 - File: inc/plugins/threaded_mode.php(305) : eval()'d code PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php(305) : eval()'d code 3 errorHandler->error_callback
/inc/plugins/threaded_mode.php 305 eval
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Undefined variable $lang - Line: 5 - File: inc/plugins/threaded_mode.php(305) : eval()'d code PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php(305) : eval()'d code 5 errorHandler->error_callback
/inc/plugins/threaded_mode.php 305 eval
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks
Warning [2] Attempt to read property "messages_in_thread" on null - Line: 5 - File: inc/plugins/threaded_mode.php(305) : eval()'d code PHP 8.1.2-1ubuntu2.14 (Linux)
File Line Function
/inc/class_error.php 153 errorHandler->error
/inc/plugins/threaded_mode.php(305) : eval()'d code 5 errorHandler->error_callback
/inc/plugins/threaded_mode.php 305 eval
/inc/plugins/threaded_mode.php 23 ThreadedMode::showthread_threaded
/inc/class_plugins.php 142 threaded_mode_showthread_threaded
/showthread.php 918 pluginSystem->run_hooks





Ok someone explain this gummy wheel problem



#2

with card readers on HP67s.

Do these wheels just disolve or what?

What makes them gummy?

Where does one get replacement wheels?

If one had an unopened package card reader can it go bad just sitting there, without ever having been used?


#3

1) yes (disolve) -- well sort of. The rubber used is not particularly stable (did HP expect them to have to last 20+ years???)

2) see above

3) See article by Dave (The lost rabbit) at...

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=57

4) yes

#4

Mike,

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,

Todd Garabedian,
Glastonbury, CT


#5

I've done about 10 card reader repairs trying various materials (o-rings, rubber feet, tubing). I've made all of these work, but by far the best one and the one probably closest to the original that I've found is silicone rubber tubing 1/4" OD x 1/8" ID. It fits on the gear shaft perfectly without the need to glue it on and provides plenty of contact area with the card (unlike the o-rings).

This is readily available from Small Parts Inc. (www.smallparts.com) (800) 220-4242. They sell 10 feet of this (enough to repair 1000 card readers!) for $24 (part # 210005). BTW, they also sell the 1/8" Delrin balls (4 of them) used in the card reader in case you loose them while doing the repair (10 for $2, part # BDLR-2) -- I've never seen these disintegrate, however.

Also, they have .005" beryllium copper sheet (part # BCS-005) that can be used to make card contact springs used inside the reader. (These springs do corrode over time.) And this same material (or the ticker stock BCS-006 or BCS-010)) can also be used to make replacement battery contact springs for the Spice series calculators. (Just cut to size, shape it like the original contact, drill a 1/16" hole in it, drill out the rivet holding the broken contact and secure the new contact with an 0-80 screw and nut. Takes about 5 minutes and looks and works great!)


#6

Katie,
Is that tubing from small parts the same as "Tygon" hose. I do have their catalog and will look up that hose you specified. Too bad they don't sell the correct spurr gear for HP-97 printers! I looked into that once.
Even though the Tygon hose is 1/4"OD x 1/8 ID, it always seems to have a little bit larger OD when slipped on the gear. My remedy has been to chuck the hose in a lathe with drill on the ID and machine off a little of the OD.


#7

Erik,

The silicone rubber tubing is much more flexible and softer than Tygon. It's about the consistency of silicone bathtub caulk and can stretch up to three times its original length. (Not that you'd want to do that in this case!). It doesn't need to be turned down at all probably because it's soft enough.

I checked with Small Parts on the 97 printer spur gear too. They don't carry any 24 pitch gears but said that they might be able to special order some. I'm going to get a price quote from them and see if it makes sense (i.e., it's cheaper than buying old 97's on ebay just for the gear). I'll assume that if I have to buy 10 or so, to get a decent price that I'll have no problem finding people on this list to share the order with. (Otherwise, I'll have to go into business repairing them, I suppose!)

-Katie


#8

Katie,

I'll gladly "pitch in" and purchase a few spare gears if that helps to keep the price down.


Viktor

#9

Hey Katie,
How about posting this info to the articles forum? It would be a good place for this info. Randy


#10

Randy,

I was planning on writing up an article on several repairs that I have some experience doing. I've just got to find some time to work on it. I'd like to put some pictures in with the write ups. It's very hard to understand what's being talked about until you have the calculator in pieces and many people are reluctant to go that far without a really good description of what to expect.

-Katie


Possibly Related Threads…
Thread Author Replies Views Last Post
  Can someone explain Mike Powell 5 1,699 10-12-2013, 11:40 PM
Last Post: FORTIN Pascal
  15c LE - PSE works and doesn't! Please explain! Alexander Oestert 6 1,916 09-28-2011, 03:23 PM
Last Post: Alexander Oestert
  Gummy wheels for 41 series card readers William L. Drylie 5 1,850 08-30-2011, 11:26 AM
Last Post: William L. Drylie
  HP-97 Card Reader NOT gummy wheel problem ZOleg 3 1,411 02-03-2009, 07:12 PM
Last Post: ZOleg
  HP-41 Card Reader NOT gummy wheel problem Rich Forest 19 4,470 01-12-2009, 10:59 AM
Last Post: Ignazio Cara (Italy)
  How would _you_ explain the marvels of HP calcs? Giancarlo (Italy) 21 4,728 02-05-2007, 09:50 PM
Last Post: dbatiz
  HP-67 Gummy Roller Successfully Repaired Grant Henson 6 1,684 12-19-2006, 07:10 PM
Last Post: Grant Henson
  Gummy Wheel Fix Peter Hendy 4 1,266 03-07-2006, 10:23 AM
Last Post: David Smith
  Gummy Case hal 12 2,674 11-09-2005, 10:59 AM
Last Post: David Smith
  Gummy wheel repair , Need O=-ring size Frederick Harvie 6 1,968 11-05-2005, 04:58 AM
Last Post: James F. Chumbley

Forum Jump: