The Pascaline (Mechanical Calculator)

This build is an improved version of the one I submitted to the STEM challenge.

The Pascaline is a mechanical calculator built by the French scientist and philosopher Blaise Pascal in 1642 (first “public release” in 1645). He wanted to help reduce his father workload during his daily tasks as a tax commissioner. The complexity of the device and the production cost prevented it from being sold to the public, but it inspired many later calculators over the next centuries.

With the Pascaline the user was able to do additions and subtractions. They could also have the result of multiplications and divisions by performing successive additions or subtractions. Of course, today it feels quite tedious to do it that way, but during the 17^th century, I bet it could be very useful.

Sources: https://en.wikipedia.org/wiki/Pascal%27s_calculator

 

Disclaimer : this set has been built only in Bricklink stud.io not in real. Therefore, it has not been tested and I can’t affirm this mechanism works the way it should. However, my goal, when designing it, was to create a prototype that would be as close as possible to the original device.

 

The mechanism was, of course, complex when Pascal designed it (the gears were not that common outside of the clockmaking world, especially gears of those sizes), but today it feels simple and elegant at the same time. It is organized in several modules, each one of them representing a group of number units. The first one on the right represents the simple numbers, the following one on the left, represents the tens, then the hundreds etc.

The sautoir is the centrepiece, as it is the one that will propagate a carry when it is time to do so, using only the influence of gravity without having the need for the gears to touch each other. So how does it work ? Additions are pretty easy, the user only has to turn the cogged wheels on the top of the device, from the left to the right, to display the first number. For additions we will only read numbers of the Tambour’s (the cylinder) bottom line. The top line will be used for subtraction.

Let’s say we want to calculate 16+5, the first number to display there would be 0 0 0 1 6. Then to add 5, we will turn the wheel on the right. When the number displayed is 0 0 0 1 9, the left wheel’s sautoir will be raised by the right wheel’s pin, and when turning the right wheel again, the sautoir will be released and the gravity will make it fall. By falling, the sautoir’s kicking pawl will push on the second gear and start turning it, making the tambour displaying the next number. So now it’s displaying 0 0 0 2 0, we just have to turn the right wheel a fifth time (because we added 5 to 16, for a reminder), and it is now displaying 0 0 0 2 1 and the addition is completed !

I hope you like this build. Feel free to comment, I'll be happy to discuss about it, and don't hesitate to give me your thoughts and advices.

Cheers!