Joined: 27 Oct 2009
|Posted: Fri Nov 08, 2019 2:56 pm Post subject: This is a nice CURTA
|This is a nice CURTA
[ Curta Type I - April 1951 ]
Before, this CURTA was no more working - with a lot of unusual issues. No idea how to use a Curta to reach such a state.
Here's the list of repairs I made:
1) The knock-out pin of the main shaft was sheared of - on both sides. It was possible to turn the crank without having the default (start) position.
Instead of removing the broken one I punched-in a replacement pin so the old one was removed in the same step (I have not the fitting tool, so I had this idea).
Part used 10.148 knock-out pin for main shaft / zero pos. disc
2) The clearing plate (10.244) was not working / blocked.
The nut was inside the clearing plate, loosed from the screw and has blocked the clearing lever.
The spider spring was slightly bent but not destroyed.
So, simply screwed back the nut on its place.
3) The clearing plate plunger 10.024 was bent so it was not free moving and get jammed sporadically.
Replaced the clearing plate plunger 10.024
4) The ten-carry lever 10.005 of the result dial (5th digit) was not working the right way and blocked the operation (rotation).
The ten-carry lever was bent and also the ten-carry lever spring.
Replaced the spring 10.007 and tuned the lever to the right shape (angle).
(another ten-carry lever spring was bent because I got stuck on this...).
5) Finally, a general cleaning and lubrication
This is a nice CURTA
:: m u r f f