HP-67 Card Reader became very touchy

[John Garza (3665)]

(10-17-2023 08:42 PM)Alevin Wrote:  I tried in an Hp-65 clutch repair with the silicone procedure, but I got troubles in getting the ensemble engine staff-worm aligned.

In respect idle gear, I made a previous repair in another HP-67 with a bronze gear, and my experience was not quite satisfactory.

That is why I am going to attempt now with a printer plastic one. Shapeways nowadays offers more printing materials to try. I will document the experience in the threat.

Keep in mind silicone is not the same as RTV or gasket maker. I've tried silicone back in the early 2000's and it did not work well. I also tried the cable insulation replacement, but it's really not needed unless the coupler itself is damaged (or crushed!) by a careless previous owner attempting repairs. The goal is to have a material inside the coupler that will not break it's grip on the smooth metal shaft, yet provide some flexibility. And you must mate the shaft into the bottom of the coupler for good alignment. Optical inspection and a 'dry-run' without sealant will aid familiarization.

I never had a problem with the gears from the auction site. Sounds like you got one that was simply wrong. Was it advertised as a 97/Topcat Idler Gear? If you go the route of fabricating new plastic ones, ensure you use material that will not wear quickly or break. The hardness trade off is between broken teeth and rounded/slipping gears. Good luck!

-J