HP-41 Permanent broken Post Fix
#1

Up for review is my permanent repair to fix your ailing 41.

As some in the forum know, I had posted the question why my two 41CVs were acting strangely. POSTS. Nothing more, nothing less. Well the following is my permanent cure for one. It's posts where helplessly cracked beyond repair. What I resorted to were two 4-40 brass standoffs about .25-.27 inches long x .1875 OD.

Finished height above board = .200

The old post was milled off with a .1875 end mill and bored down about the thickness of the board (.070)

They were then epoxied into place.

Now proper torque can be applied to the 4-40 screws and the unit behaves as it should. Hopefully it will last another 29 years!


Edited: 17 May 2011, 10:49 p.m.

#2

That's a very elegant solution. I just lazy out and slip slightly too-tight springs over the split plastic. It works but not as prettily as your brass fittings.

#3

Brilliant solution, and great pics!

#4

Great solution! Would you have some spare standoffs as I just have one 41C with the exact same problem?

#5

I should have a few next week. I requested a sample lot from Keystone Electronics. They will need to be faced back from their .375 length to .25-.27. Drop me an email off-line for info.

#6

These ones were shattered and sheared off at the board. No spring would have helped them!

#7

Excellent solution. I've got a couple of machines that can use this fix. But isn't the .1875 OD a little too big for the holes in the processor board? I thought that the posts were 4.3mm (0.169) and the holes in the processor boards were 4.5mm (0.177). Did you have to slightly enlarge the holes in the processor board?

Monte

#8

aj, can you post a link with what exactly you ordered, I think there might be a few people (including myself) that want to try your truly elegant and well working solution.

Thanks!

Peter

#9

I'm interested in a couple of these brass cylinders, too.

Are these available in the suitable legth for the upper posts, too?

Is the screw thread already there?

Thanks

Ray



Possibly Related Threads…
Thread Author Replies Views Last Post
  Broken keys on HP Prime? Tarcisi C 0 1,433 12-10-2013, 05:59 PM
Last Post: Tarcisi C
  HP-41(CL): The easiest way to transfer FOCAL programs from a Linux PC to the HP-41 Geir Isene 13 5,559 12-05-2013, 02:40 AM
Last Post: Hans Brueggemann
  (deleted post) deleted 2 1,326 11-03-2013, 06:24 AM
Last Post: deleted
  Is my HP Prime broken ? Michael de Estrada 10 3,010 10-13-2013, 11:16 AM
Last Post: Mike Powell
  trig scales on the Post Versalog slide rule Al 12 3,593 09-15-2013, 06:01 AM
Last Post: John I.
  (deleted post) deleted 19 4,393 08-31-2013, 03:46 AM
Last Post: pascal_meheut
  Broken HP-97 to spare? davorin 3 1,653 08-29-2013, 01:08 AM
Last Post: davorin
  WP-34S Overlay - making it a bit more permanent? Marcel Samek 1 1,080 07-05-2013, 09:02 PM
Last Post: htom trites jr
  SCIOVR and ENGOVR in FIX mode Andrew Nikitin 5 1,782 07-02-2013, 04:46 AM
Last Post: Victor Koechli
  (deleted post) deleted 2 1,310 03-25-2013, 06:41 PM
Last Post: Eric Smith

Forum Jump: