The Curta.org Bulletin Board

AJP · Posted: Fri May 05, 2023 9:30 pm Post subject: Base plate screw

Whilst competing on a rally a few weeks ago with my wife navigating for me, we unfortunately lost one of the screws that hold the base plate in position on her Curta, does anyone have any spare ones they would sell?

Alternatively do you know the size/thread profile so I could buy an alternative?

Henk · Joined: 28 Jul 2022 Posts: 1 Location: The Netherlands

Dear Ajp,

I recently came across two of them on the german ebay. Mayby you could contact the seller. https://www.kleinanzeigen.de/s-anzeige/curta-bodenschrauben-2x/2402942975-234-2694

murff · Joined: 27 Oct 2009 Posts: 586 Location: Switzerland

I will send you a screw for free - please PM your address....

Happy Coronation Day
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Kmcqueen · Joined: 14 Apr 2023 Posts: 28 Location: Portland OR, USA

Related to these base plate screws......Do we know why some of them seem to corrode while the rest of the Curta is fine?? Does it have something to do with the cushion in the bottom of the can ??

(for example - like these)

https://ibb.co/DDNj90d

murff · Joined: 27 Oct 2009 Posts: 586 Location: Switzerland

The screws are made of a brass alloy (Ms58Pb) and nickel-plated. Under "normal" conditions, these screws are corrosion resistant - but there are definitely substances that can attack this corrosion protection (e.g. decomposed rubber...?).

In the first Curtas, these screws of the base plate were made of steel and mostly black discolored...

Therefore, I have replaced the rubber padding on all Curta containers with a wool felt, which has about the same elasticity and is chemically neutral.
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