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Restoring HP-41CX

PostPosted: Mon Jul 27, 2009 10:26 pm
by j beede
Hello,
I am in the process of restoring a 41CX that is in fine cosmetic condiiton, but has disintegrated case posts. I believe I have repaired the recessed screw holes on the back half of the case under the rubber feet. Now the challenge is to recreate the upper post set which have been reduced to nearly nothing. About 1mm of the two upper posts remains visible well below the circuit board level. I can just barely get a #2-56 screw to cross thread into the tiny bits of post left. I have prepared a #2-56 "coupler" with a short male end that I would like to screw/glue into the remaining post hole. The female end of the coupler is being trimmed to the correct length to receive a #2-56 machine screw passed through the repaired case back. My question is this--what adhesive would you use to bond the brass couplers to the remaining post stub and to the adjacent pcb material? I am concerned that injecting adhesive around the post stub could compromise LNx and summation key operation. Any comments or recommendations?
Thanks, j

Re: Restoring HP-41CX

PostPosted: Tue Jul 28, 2009 6:54 am
by Garth
I've never had a 41 open, but this sounds like a job for J-B Weld. If you get too much in one area for the keys to move freely, you can carve it down with the Dremell tool after it's cured.

Re: Restoring HP-41CX

PostPosted: Fri Oct 23, 2009 9:57 pm
by FrostbiteFrank
Try FastCap 2p-10 adhesive - it's a cyanoacrylate that make superglue seem like post-it adhesive. Being cyanoacrylate, it's brittle - if you build up a post out of the gel, you'll probably have to drill & tap it rather than just screw something into it. Self-tapping screws might work well too if you're careful.

Re: Restoring HP-41CX

PostPosted: Tue Oct 27, 2009 7:37 pm
by Klaus
Be sure to test the adhesive at an invisible spot of the calc first. Some tend to leave white stain after drying.