Mechanical calculators: Original Odhner model 227

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This machine was manufactured by Odhner in Goteborg, Sweden, somewhere between 1955 and 1968. It was my first mechanical calculator, a gift from my wife's cousin, in December 2009. It was all locked up, but disassembling the cover and trying to understand its workings quickly got me to unlock it. Lubricating and cleaning without disassembly, I got it to work smoothly. It is only missing the handle of the accumulator reset crank, and the button of the backtransfer mechanism.

I have no pictures of the insides of this machine, and no plans to disassemble it, since it is in such a good working condition. I would like to restore the exterior, but I tend to let it stay as it is, with all the apparent wear from many years of use.

28/02/2016: I noticed in a YouTube video that the operation of another machine was different from mine: to set the numbers, it should not be necessary to press the thumb button, as in my machine. I took out the cover, trying to find an adjustment. It turned out that there should be a pin inside the cradle for the crank. This pin would push the thumb lever to the left, as in the YouTube machine. This part was missing in my machine. I replaced it easily with a flat-top screw cut to size. This detail also made the back transfer mechanism work correctly.

Have a mechanical calculator stored somewhere, and want to get rid of it? Send it to me!

1955-1968 Original Odhner model 227 s/n 820036




 Serial number

More about this machine

Calculating a square root in an Odhner 227

Odhner machines history and models (1)

Odhner machines history and models (2)


Technical description of the Odhner pinwheel mechanism

Manual of the Original Odhner 227 and other models (in Italian)

Video: an Odhner 227 at work

Video: how pinwheel calculators work

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oo.txt ยท Last modified: 2016/02/28 18:59 by clodoveu
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