The average user of this site is assumed to either already posess at least one mechanical calculator, or have a decent technical knowlege of their operation. The following are some consise operating instructions which I have found it useful to send to sellers, when trying to acertain if a machine is fully operational. Feel free to copy any information from this page.
The clearing lever is the small hoop attached to the top. This can be folded out. While lifting the top of the calculator away from the main part, rotate the clearing lever one full rotation clockwise. This should clear the upper registers. Set the sliders on the side such that all show 0 apart from the rightmost, which should show 1. Ensure that the upper part of the calculator is rotated as far clockwise as it will go, in the same way theat the clearing lever was operated. Pull the crank out, such that a red band shows around the base of the crank, and push the slider on the side into the upper position. Rotate the crank one full turn clockwise. All of the digits on the top of the machine should show 9s. Clear the registers as before.
To clear all registers, rotate both of the handles at then ends of the carriage one full turn. Set the sliders on the front such that all show 0 apart from the rightmost, which should show 1. Ensure that the carriage is moved all the way to the left, Rotate the crank one full turn (this is usually anticlockwise, but depends on the machine. If these is an arrow, rotate in the direction of Subtraction). All of the digits on the output and counter registers should show 9s. Clear the registers as before.
To clear all registers, pull all clearing handles fully forwards and release. Enter the number 1, either by sliders or keypad, in the case of the Facit. Ensure that the carriage is moved all the way to the left, Rotate the crank one full turn (this is usually anticlockwise, but depends on the machine. If these is an arrow, rotate in the direction of Subtraction). All of the digits on the output and counter registers should show 9s. Clear the registers as before.
The operation of these is always slightly different depending on the model. On some of the individual manufacturer pages I have added basic descriptions, and hope to add more.