Gualala Gadget FAQ

How are the models designed?

The models are designed in Blender. They use a variety of different mechanisms to lift the balls, but all are designed for 8mm, or 5/16th inch metal bearing balls. Because the tracks are designed to be the minimum size possible, so as to best highlight the balls as they travel the mazes, it's important that the balls be clean and perfectly spherical, and also heavy. It's also important that the models be almost perfectly level.

In some cases an individual model is designed and prototyped in stages, first testing the lifting mechanism, then the means of descent. If everything checks out, the sections are combined, and mounting locations for motor, solar panel, battery and switches are added. Five or six prototypes are built and run for an extended time to ensure they operate with reasonable reliability. Usually it's necessary to make adjustments to the tracks, especially those on descent, to reduce the frequency at which balls drop off the model. Once this is done, the final design is ready to produce.

How are the models made?

Each model is 3D printed using PLA plastic on consumer FDM printers. This takes anywhere from six to fifteen hours, depending on each model's size and complexity. A model is made from two to seven PLA parts, which are inspected and cleaned of any residual plastic that's a byproduct of the printing process. (None of the models require support material, which simplifies the cleaning process). Once the PLA parts are prepared they, along with the electric parts are assembled into complete models. There's no painting -- the plastic is the color it appears.

How do i care for my gadget?

The most important thing is to not expose it to excess heat. PLA plastic can deform at temperatures above 40 degrees Celsius, or about 104 degrees Fahrenheit. The gadget may look OK, but deformations of the tracks may prevent the balls from traveling reliably, and there's not much you can do to fix it. Be especially careful about leaving it in a car that might get hot.

You'll want to keep the balls and tracks clean. If it is battery powered, be sure to remove the batteries when storing the model. When replacing the batteries be careful not to apply to much pressure as it is possible to break the plastic. If, however, you do break some of the plastic you'll probably find that the model still works just fine. (Many of the most fragile plastic parts are there just to support the printing process. Once the gadget is printed, the only function they serve is to look important).

The best place for the solar models is in a sunny window, where they can be left indefinitely. PLA has a durable color, so you shouldn't have to worry about the color fading. When the sun strikes the panel the gadget will run, and even when there isn't direct sun you'll still find that the gadget operates, just very slowly, and in moderate light the gadget will stop.