The Original-Odhner 24 mechanical calculator

The Original-Odhner model 24 is a mechanical calculator with a pinwheel mechanism. It has a large capacity of 20 digits, and a back transfer mechanism. It was made in Göteborg in Sweden from 1940 (or maybe a bit earlier) until about 1948.

In 1875 Willgodt Odhner made the pinwheel calculator that was the ancestor of almost all pinwheel machines that came after it. He died in 1905, after which his sons took over his calculator production business. It was they who moved to Sweden when the business was taken over after the Russian revolution (NOTE: In the video erroneously imply that Willgodt moved to Sweden).

For more information on this and other calculators in my collection, please visit my website:
https://www.jaapsch.net/mechcalc/

0:00 Introduction
0:19 History
2:10 Addition
2:42 Subtraction
2:57 Clearing register and counter
3:07 Multiplication
4:17 Clearing input
5:25 Counter
6:13 Division
8:02 Main carry mechanism
9:27 Counter carry mechanism
10:13 Back transfer mechanism
11:36 Outro