Introduction: Musical Abacus
The abacus (plural abaci or abacuses), also called a counting frame, is a calculating tool that was in use in Europe, China and Russia, centuries before the adoption of the written Hindu–Arabic numeral system and is still used by merchants, traders and clerks in some parts of Eastern Europe, Russia, China and Africa. Today, abaci are often constructed as a bamboo frame with beads sliding on wires, but originally they were beans or stones moved in grooves in sand or on tablets of wood, stone, or metal.
Music is an art form and cultural activity whose medium is sound and silence. The common elements of music are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics (loudness and softness), and the sonic qualities of timbre and texture (which are sometimes termed the "color" of a musical sound). Different styles or types of music may emphasize, de-emphasize or omit some of these elements.
Today we made a combination of a music box and an abacus, aka "Musical Abacus" (original we know). Art and Science have always seemed to be separated by popular culture, seen as vastly different from each other, but as we are learning in Physics, sound, music, and the like are very much tied to science. We wanted to combine the two again in our project and thus are here to present our Musical Abacus
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Design and Print!
You'll need to design your pieces for your abacus, for us we decided on using polygons and increasing the side count for every number we moved up on each rod. This meant we started with a triangle and ended each rod with a dodecagon (12-sided polygon)
We used Onshape, a free online, cloud-based CAD program, to design and save our pieces. You can make multiple pieces per file. Each piece should be ~30-35 mm from side to sideWe kept evens and odds on their own file for ease of printing. We did not choose any specific colors, just what was available. For our file, we saved them as a .stl with medium quality and in millimeters (you can leave the rest of the settings alone).
To print 5 of the pieces took ~55 minutes so total time for 30 pieces was ~330 minutes. Larger pieces will take longer time so make sure to know how much time you have to complete this.
Step 2: Woodworking
The wooden frame is the fundamental part of the abacus. You need to make sure you construct two identical frames, one main and one support, the only difference being the rods in the front and a support beam in the back. First, definitely make sure you have measured and marked absolutely everything. This is the most important step! It's easy for a project to fail because somebody measured in meters, not feet. Once everything is marked, cut out the basic pieces of the frame and sand them. Next mark the holes you need to drill, drill, and screw. When done, it may be disappointing, but now you need to take it all apart--at least if you are satisfied with the product. This is because you are going to varnish next. Note that we just used a clear gloss--if you are using a color varnish you will probably have to use it, let it dry, and then apply the gloss. The best thing to do for the gloss is to take two large boards, clamp them together, and leave just enough space to put the boards upright. Varnish the boards and put them in the set up. After a short time and a light varnish, sand briefly and repeat with a heavier coat. This time let everything sit for a day.
Step 3: Arduino
The code of the Arduino can be found here. It's starts by defining each note as a frequency and each measure as a length of time. We then organize the notes and measures such that it plays the Imperial March from Star Wars.
For the Arduino, you need to replicate the picture. To explain, you need to have a 5 volt wire running to positive end of the circuit, and from the negative end of the circuit, you must have a wire running to the ground. Since the code set the button output from PWM 2, you must run a wire to one end of the button. Moving a few pinholes away, you will connect a 330 ohm wire from the button to a positive pinhole and a wire to the negative pinhole. Now you are able to connect the speaker. The speaker is set to output 8, so connect a wire from PWM 8 to the positive end. From the negative end of the speaker, connect a wire to a positive pinhole. You have now circuited your Arduino.
Step 4: Finishing Up and Putting It All Together
Part of this last step is optional, but recommended in order to make the abacus look as good as it can. Polyurethane varnish or any sort of varnish can improve the quality of the build by just making it look more appealing. The instructions for using the varnish vary depending on the type of varnish you purchase, but for this project the pieces of the abacus were coated in one coat of varnish which was left to dry overnight, then they were lightly sanded the next day, and another coat of varnish was applied. After the second coat of varnish is applied then the pieces must be left to dry overnight for optimal results.
Finally, the pieces of the abacus were screwed together once again in the same way that they were screwed together a few steps before this (This is very important, the pieces may be misaligned if you mix up what part goes where). A drill is recommended to make sure that everything is as tight as it can possibly be. After assembling the front and back frames of the abacus, screw in the hinges in order to connect the two pieces. After this, the rods with the 3D printed pieces can be placed into the drilled holes in the front piece of the abacus. It may be a little tough to put them in at first, and it may seem as if the rod will snap, but it won't. Finally, enjoy the finished product!