Hp-41C card reader - dead

[teenix]

(05-17-2020 12:39 PM)Vintage63 Wrote:  In my tool box I have found this cable.
Unfortunately I don't think it is good for the 'clutch' as it is quite stiff / rigid.

Anyway I did some practiced stripping the inside insulation and I have a couple of questions:

1) the piece of insulation has to have a perfect center hole, correct ?
2) as the hole I have is too tight it doesn't fit onto the copper gear worm axle. Do I have to enlarge it a little bit before sliding it on ?

I have a black satellite dish cable in the flat which sticks out from under the floor. This has a flexy feel and touch to it.
I'm not using satellite at all so, maybe, I could cut a piece off this and hide the rest and give it a go ?


Thank you

Marco

Yes, centred would be good to minimise vibration and be the correct size to mate with the motor shaft.

The drill size to attach the worm gear is 5/64". It should be drilled into the coupler just enough so that the worm gear fits snugly. It must also be drilled central to avoid vibration.

this link has more detailed info.

https://www.hpmuseum.org/forum/thread-12...#pid110378

The coupler must not be any longer than the aluminium sleeve or it may rub against the motor casing and put too much load on the motor.

RG58 coax inner insulator is pliable and a good hole size once the central copper wire is removed which makes it easy to attach and bind to the motor shaft, but it is also stiff when cut to the coupler length.

I think if the white coax sheath is too stiff, it may not easily expand onto the motor shaft meaning excessive force may be required to fit it or it may slip.

cheers

Tony