**Facit C1-13 & ESA-01**

**Facit CI-13**

**Facit C1-13**

Mechanical, pin-wheel mechanism, with key setting.

Can multiply a 10 digit number by an 8 digit number and give a 13 digit answer.

Functions - Addition/Subtraction and Multiplication/Division/Square roots using special techniques.

310 mm x 215 mm x 150 mm (12" x 8.5" x 6"), 6.75 Kg (15 lbs.).

Made in Sweden by Atvidaberg-Facit.

Serial number 799426 made in 1961 according to the serial number list on James Redin's site (see below).

A later, more angular model was on sale till the early 1970s.

Views with the covers removed.

Top: the front.

Bottom: the rear.

In both of these views

A: The pinwheels, which are set by pressing the keys.

B: The mechanism connected to the keys which sets the pinwheels.

C: Rotating mechanism for performing the carry function.

John Wolff's website has detailed technical information about this model, and how to dismantle it for servicing (not to be attempted by the mechanically challenged!). See www.johnwolff.id.au/calculators/Tech/TechIndex.htm

Key-set pinwheel calculators

An Odhner pinwheel calculator.

The Facit T, the first Facit pinwheel calculator with key setting (1932).

The first Facit mechanical calculators had the standard layout of the Odhner-type pinwheel calculator, as typically shown on the left, however in 1932 Facit introduced the *Facit T* machine with key setting.

Numbers were set on these machines by pressing keys, which was quicker, and less prone to error, than the lever-setting of other pin-wheel machines.

From then until the models were discontinued in the early 1970s all Facit mechanical calculators employed key setting.

**Facit ESA-01**

**Facit ESA-O1**

Electro-mechanical, pin-wheel calculator.

Can multiply a 9 digit number by an 8 digit number and give a 13 digit answer.

Functions - Addition/Subtraction/Multiplication/Division.

282 mm x 260 mm x 182 mm (11" x 10" x 7"), 13 Kg (28.5 lbs.).

Made in Sweden by Atvidaberg-Facit.

Serial number 356611 made in 1954 according to the serial number list on James Redin's site (see below).

This is an electrically driven machine and is slightly earlier than the mechanical machine at the top of this page.

With the front cover removed. There is little space wasted.

With the rear cover removed showing the electric motor made by Electrolux. In 1972, nearly 20 years after this machine was made, Electrolux bought out the ailing Facit company which had been hit by falling profits on electronic calculators.

James Redin has produced a table illustrating the development of Facit mechanical calculator models and their serial numbers at http://www.xnumber.com/xnumber/cmisc_facit_page.htm

There is a Youtube video showing the operation of an electrically powered Facit model CA1-13 calculator at https://www.youtube.com/watch?v=hgV9DbfIlgg. This shows the incredible mechanical complexity squeezed into such a small space with this type of machine.

Also, Christofer NĂ¶ring has an interesting history of Facit calculators at http://www.xnumber.com/xnumber/facit_history.htm

The story of Facit mechanical calculators and their demise is told in the YouTube video* "The Rapid Collapse of the Swedish Mechanical Calculator Industry"* at www.youtube.com/watch?v=QJPMIjVGzd0

**Mechanical Calculators**

*Vintage Calculators *

Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.