1004 Clodoveu Davis

Mechanical calculators: FACIT 10-04

I purchased this machine in January 2013 at an online auction site. The 10-04 model was the very last manual calculator manufactured by Facit in Sweden. The model is very similar to the CM2-16, with the same specs, and a few external differences, including a plastic cover. It has a handle that pops out in the lower front to help moving the machine around in an office desk.

This one is in pretty good shape, but the lubrication inside is the most deteriorated I have seen. Much grease has been applied, and it hardened in some parts. When I got it, it was completely stuck. Some directed cleaning and a thorough spray of kerosene have loosened part of the main subsystems, but it was not nearly enough. A full disassembly and cleaning was required, so that the machine could operate smoothly again.

I finally got around to disassembling, cleaning and reassembling the machine in January 2014. Inside, most parts are yellowish, I guess from zinc plating. This plating has reduced the number of stains in the sheet metal parts, but most of the problem was, again, the old lubricants. I experimented this time with a small and cheap ultrasonic cleaning device, using kerosene as a solvent (see photo below). It worked very well, especially with gears, screws and other parts with holes and details that are hard to get at with a brush or a cleaning cloth.

I noticed some other minor differences from the CM2-16, most of which related to the new plastic cover. Some rubber parts were deteriorated, but I was lucky in finding/rigging adequate replacements for the rubber rollers in the back and for the feet in the front. Overall, I prefer the style of the CM2-16's cover and buttons, but after the renovation the 10-04 works slightly better. Maybe I'll get to work again on the CM2-16 in the near future, mainly trying to make its transfer mechanism smoother, possibly with the aid of the ultrasonic cleaner.

There's no reference as to the year of manufacture, but the 10-04 model was produced in Facit's final years of operation in Sweden, between 1967 and 1969 ( details here and here).

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

c1969 FACIT 10-04 s/n 1953833

As purchased, in January 2013

Detail of the degraded lubrication

Insides, pre-cleaning

Right side, partial disassembly

Left side, view of the reset mechanisms

Back left corner locking mechanisms

Back left corner, almost fully disassembled

The 10-04 is almost identical to the CM2-16, but notice that many parts of the 10-04 are yellow from zinc plating, while CM2-16 parts have a natural steel color.