Zehntausendste Curta Type 2



Institute of Geodesy and Photogrammetry ETH Zurich 1957




First Curta this year - and so first cleaning and restauration job

Nice catch! So this is one of the very late black-body Type 2 machines - I guess regular (matte) metal canister, usual lettering, all metal - anything unusual about this particular example except for the SN?

The special thing about this Curta is that it was used very often and rough (in the field) - the metal canister looks like a cow has eaten it. The main shaft is bent and the zero positioner disc has lost most of the teeth so you can turn the crank anti clock wise... And the Curta is really dirty inside and outside. It only works in sticky way.
With only some basic tools (none of the special Contina tools) it will be a challenge to make this Curta fit again!

The work is in progress, now...

Update will follow

So a first round is done...
- the whole Curta is deeply cleaned and lubricated
- the bent main shaft was adjusted to straight so the crank is in a right angle now
- the zero positioner disc was replaced
- a bent axle of a setting knob was replaced
Maybe I'll try to replace the Clearing lever which is bent and not able to latching correctly.

Here are some pictures of this successful operation (and a good lesson in Curta mechanics...):

Curta Type 2 - die Zehntausendste



[ Removing the top of the Curta ]

You're a brave man taking those things to bits, pal. Best of luck

update

In addition to my repair adventure I replaced the clearing lever on the "Zehntausendste" and on a newly repaired Curta Type 2 (an early grey with triple group of the red sliders) . In both cases the rings were not broken but they not correctly snapped into the working position.



The challenge is that you have to rivet with the correct force so that the lever is still moveable...


( more pictures on my site )

In another try I replaced the red brittle color of the subtract stripe at the crank. I used FIMO - a plastic modeling compound which can be hardened in a oven.


Subtract stripe - 1) blank metal 2) red, new replaced with FIMO 3) original red, brittle color

Fascinating; great work and thanks for the update.