Card reader repair


I am working on a couple of hp41 card readers I recently picked up. I am following the directions on replacing the gummy pinch roller which I have found very helpful but when I opened the case I found 2 of the internal screw post on the case are broken. Also, one of the internal screws is missing so it looks like someone had opened this up at some time. My question is has anyone had any success repairing the internal screw posts? I can use superglue to get everything back together but I think the repair will be too brittle and will fail with normal wear. I am thinking of trying one of the newer superglue's that are advertised to be more pliable. Does anyone have any thoughts or suggestions or should I just save this for parts? The reader did work before but left the gummy residue and had some external trama so I'm sure it was dropped. Thanks for your help.



As far as "super glues" go, try your local hobby shop and see if they have "plasti-zap", get a bottle of "kicker" to go with it; better yet visit a model aviation field in your area one weekend and I bet somebody would have this stuff in their toolbox and be more than happy to give you a drop and a shot. The "plasti-zap" is just another cyanocrylate glue (read super glue), but the "kicker" is kind of a vanilla smelling spray that acts as an accelerant. Put the glue on the parts, put the parts together and then spray a shot of the "kicker". NOT have your eyes or nose near this stuff when you do it, because when the chemical reaction occurs, it will form a whisp of smoke that will make you rub your eyes for quite a while. If you want to build up the area around the post, baking soda sprinkled into the wet cyanocrylate glue will form a good bond. You put the kicker to that and you'll break something else before you break the repaired area. Hope this helps, let us know.


Thanks Dave, I'll give it a try and let you know. Interesting, I have two readers I am working on, I planned on replaceing the pinch roller in each with o-rings, one seems to work fine, the other the o-rings are slipping, same size o-rings, I'm wondering if the shaft size was changed during production.
Also, thanks to you, Ty and the Museum for posting the repair info.


Dane, perhaps the o-rings you used are slightly too small in diameter or the inner diameter is too big. Randy


I had problems with o-rings slipping. I think the ones I got are too hard. So I went with the fuel tubing method. The o-rings I tried I picked up from home depot. They are DANCO #60 o-rings. They are the right size as per the instructions on the site here. Maybe there's softer o-rings out there?



I bought the o-rings at the same store, all the same size, they work on one card reader and not another, leads me to believe the shafts are a slightly different size. I'm going to try tubing on the second one. Just was curious if anyone else had noticed the same problem.


I have tried O-rings from about 6 different sources and the problem I have is they place too much tension of the reader that cannot be adjusted out with the cam pin adjustment, so the cards jam. They seem to measure properly and inspection under a stereoscope looks like they should work. Fuel tubing is my preferred roller.


I had the same problem with the o-rings slipping slightly (just enough to move the card at the wrong speed). My solution was to remove them and place a very, very, VERY tiny drop of Superglue on the shaft, and then put the o-rings back. The card reader has worked flawlessly ever since I fixed it (almost exactly a year ago).


When I repaired my card reader with the o-ring method I had to file down the rings a bit to make them the right size. Randy


I've done a couple of dozen card reader repairs and after trying almost everything, have found silicone rubber tubing sold by Small Parts, Inc. to be by far the best solution. It's 1/4" OD x 1/8" ID sells for $24.24 for a 10-foot length under part number: U-210005. It fits the shaft tightly with no need for glue and works perfectly every time with never any slippage or need to make adjustments.

Small Parts, Inc. is at:

Possibly Related Threads...
Thread Author Replies Views Last Post
  Reasonable price for a 41C, Quad Mem, Time, Navigation and Card reader module? Eelco Rouw 10 3,731 12-12-2013, 01:52 AM
Last Post: Eelco Rouw
  hp-67 card reader problem. Marcel Samek 5 2,545 12-09-2013, 09:09 PM
Last Post: Paul Berger (Canada)
  HP-97 card reader pinch roller axle davorin 2 1,275 09-15-2013, 08:47 AM
Last Post: aj04062
  HP-97 Card Reader davorin 3 1,480 09-13-2013, 04:21 PM
Last Post: Stephan Matthys
  HP-67 Card Reader Repair Question aj04062 1 1,218 08-08-2013, 11:15 AM
Last Post: Randy
  Hp-67 card reader: tantalum capacitor identification Ignacio Sánchez 8 2,546 06-02-2013, 07:26 PM
Last Post: aj04062
  Testing card reader motor for 65 Michae Altmann 2 1,251 03-17-2013, 09:24 PM
Last Post: Randy
  Repaired HP-97 card reader doesn't show any signs of life jbssm 6 2,031 02-17-2013, 03:15 AM
Last Post: Alberto Fenini
  HP 65 card reader problem H Fischer 3 1,187 11-24-2012, 12:11 PM
Last Post: H Fischer
  41CL and Card reader Prabhu Bhooplapur 3 1,269 10-18-2012, 07:40 AM
Last Post: Ángel Martin

Forum Jump: