The Hamann Delta mechanical calculator @jaapsch2

Jaap Scherphuis | The Hamann Delta mechanical calculator @jaapsch2 | Uploaded March 2024 | Updated October 2024, 2 hours ago.
The Hamann Delta is an electrically driven mechanical calculator made between 1935 and 1939. It uses the same latched gear mechanism as the Hamann Manus, but has a full keyboard.

For more information about this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc

0:00 Introduction, History
0:45 Addition
1:40 Automatic division
3:44 Outro

The Pocket Counter, a small adding machine

$The Quixsum Fractional Adding Machine The Quixsum Fractional Adding Machine is an adding machine for lengths in feet, inches, and fractions of an inch. It was made in 1924. It is very rare as only about 600 were ever made. Stephen Freeborn has a nice video of it too: https://youtu.be/7f4Q-YwIhKw For more information about this and other machines in my collection, please visit my website: https://www.jaapsch.net/mechcalc/ 0:00 Introduction 0:12 History 1:19 Adding 4:04 Clearing 5:02 Opening case 5:02 Opening case 5:33 Mechanism 6:57 Rarity 7:57 Outro$

The mechanism of the Add-em toy adding machine