Hp-41C card reader - dead

[teenix]

Was the coax RG-58 type?, this should work. Inner translucent core diameter = 0.120", inner solid copper core = 0.030". The translucent core is flexible and has good friction qualities to grip the motor shaft.

Details for making one can be found in my Classic Notes here under "Gummy Repair"

Having the worm gear sitting in place like that is no guarantee that it is aligned properly to the center line of the motor shaft. Any misalignment will result in vibration and the possibility of motor damage and faulty card reading and writing.

If you glue the motor shaft to the worm gear and it is out of alignment then you have to hope it will come apart to repair again, plus remove all the hardened glue. Pulling hard on the helical gear to remove it from the motor shaft may damage the motor.

You also need to make sure the helical shaft end is positioned onto the thrust bearing located in the plastic frame which minimizes noise and possible damage to the motor bearings over time.

It is difficult for a home repair to ensure correct alignment, you can only do your best.

There are some details on card reader maintenance near the end of the 97 service manual. (June '82)

cheers

Tony

(04-22-2022 04:54 PM)Vintage63 Wrote:  I'm having a go at it again after 2 years.
Unfortunately the coaxial cable can fit over the worm gear, I have to machine it slightly, but is too big to fit snugly on the motor axle.
I removed the gunky stuff that was on the 'big' end of the worm gear.
Can I in some way 'glue' the worm gear over the motor axle with white glue to give it a bit of flexibility?
Attached a photo of the motor and worm gear as they look right now, not secured.



Thank you
Marco