The Abacus

I was inspired by this next project as I was working tirelessly at my desk at the bank. As you can imagine, as a banker I work with numbers quite a bit. Part of my job is to maintain the integrity of those numbers, balancing everything to the penny.

As I finished double checking the total of a stack of checks, I rubbed my hand and looked at the sheet of numbers I had just written. It occured to me there must be a faster way to do this. If only we had some form of mechanical device that would assist us in adding and subtracting numbers. Such a device would completely change the way bankers do business.

I immediately took it upon myself to do a little research online and, what do you know, such a device already exists. It is called an abacus. I have decided to take it upon myself to construct such a device to use at work. I hope I don’t make my coworkers jealous.

This first picture shows my design. The colors will be different depending on the type of wood I use but you get the idea. There have been several iterations in the design of the abacus. I chose this 1/4 configuration with 1 “heaven bead” in the upper section and four “earth beads” in the lower section.

My father-in-law had some left-over wood from building Abby’s rocking boat so I will be making this primarily out of poplar. Here I have cut the blanks for the top, bottom, left and right, and the cross piece.

The next step will be to mark and drill the holes for the rods. I originally thought I would use wooden dowels but I need them only 1/8″ thick. Instead, I found some 1/8″ metal rods that will work perfect. They are gold colored which will match the L brackets I use on the corners later.

Here I have everything cut and temporarily clamped together just so I can see the actual size.

I used 45 degree angles on the corners so it will look nice. Eventually, I will glue the whole thing together and then use the L brackets to secure it.

I decided to try something I never have before. The abacus generally has marks on the cross piece separating the lower and upper decks to indicate which rods are the 1 unit, 1,000 unit, and 1,000,000 unit rods. I am going to use a small piece of rosewood inlayed in the cross piece as my marks. Here I have used my router table to cut the 1/4″ wide, 1/8″ deep slots for the rosewood. Incidentally, I will also be using two different colored beads as shown in my diagram above to help easily determine the value of the rod.

Everything will have a coat or two of finish. However, I didn’t want to try to finish it when it was completely assembled to avoid getting finish on the beads or rods themselves. I will put a couple coats of finish on the individual pieces and then assemble them together.

You can see here I found a great temporary use of my rods, making the job of applying a coat of finish fairly easy.