12-21-2021
Polystix Modeling Materials
The exact geometry of polystix can be made by symmetrically arranging sticks. Here, we consider some of the possible reusable materials that can be used to make polystix.
The sticks
Figure12: Sticks.
Many rod- or stick-like materials can be used to build polystix. Uniform sticks or rods with a length between 5 to 100 times their diameter can be used for most small-scale designs. The rods must have some rigidity as they will be under compression. Materials that I have used to make polystix are: timber, found sticks, chopsticks, popsicle sticks, toothpicks, matches, straws, cotton swabs, pencils, metal, and glass rods (figure12). I’ve found that toothpicks can be an affordable choice, with over 10,000 cylinders costing under $10 USD (2022). Toothpicks are available in different colors and sizes, or can also easily be dyed. The downside to building polystix with toothpicks is that their small size makes patterns harder to distinguish and requires a lot of dexterity. Also, toothpicks' sharp ends are pokey and can be difficult to handle. Pencils are easier to see and handle, but are a more costly choice.
The Bands
Figure13: Rubber bands.
To hold all of the rods in place, the bundles of rods (that are on the same axis) are bound together with compression. This compression can be provided by using various means, some options are: string, elastic rubber bands, nylon, natural fiber, twine or metal wire. For small arrangements (under 3 inches) using latex-free 7/8” x 1/16” “loom” style rubber bands work great. Rubber bands are available in bright colors (figure13), which can help to keep track of different designs. Big rods can be restrained with rubber clamping bands or steel cable ties, but I have found when working at larger scales it becomes more practical to use templates and fixtures to keep the rods in place.
The Glue
Figure14: Glue.
Polystix models and all of these arrangements made with cylinders or convex prisms do not overlap and can come apart unless fixed into place via compression, interlocking mechanisms, glue or by some other means. Rubber bands can wear out and weaken after a few months, so to keep a model around longer, glue is a great option. I have used super glue, unfortunately it has a strong odor and can dissolve the rubber bands before everything is set in place. I have also effectively used wood glue, paste, Elmer's glue, or acrylic medium (figure 14). Instead of gluing each individual connection, which can be tedious, the entire polystix structure can also be dipped in a fluid medium, followed by vigorously shaking to remove the excess glue.
Each material and gluing method has its own unique advantages and disadvantages. In upcoming posts we will cover how to work with polystix patterns in 2-dimensions, on paper in place of physical models. Building polystix models is a physical activity that can take sustained focus. Determining how accessible, and the amount of math to involve when modeling polystix should be considered and varied based on the abilities and resources available to those considering these projects.
Next, we finally find out how to build a tetrastix!
copyright 2021 Anduriel Widmark
Posts:
1- Polystix blog introduction.
5- Polystix modeling materials.
9- Tetrastix shadow projections.
15- Hexastix design variations.