Solarbotics Solar Marble Machine Kit (Solderless Version) Offers seven 3/8-inch steel balls Solar-powered or hand-crank operation Includes a GM9 motor Easy to build, with engraved building notes Operates in indoor light The Solarbotics Solar Marble Machine Kit (Solderless Version) is enabled by Solarengine technology that keeps on moving even in low indoor light. The Solderless Solar version of the Marble Machine brings the same tick-tock pulse movement but with none of the molten metal. The only tools required to get this beauty running are a Phillips-head screwdriver, some glue, and a bit of elbow grease. The Solarengine circuit stores the light from the solar cell, and releases it in an occasional pulse that drives the mechanics. In sunlight, the motor will pulse every few seconds, and drop a ball every half minute. In indoor light, motor pulses decrease to every few minutes (be patient). But you can always use the hand crank to manually advance the marble wheel.
