SOLAROLLER COMPETITION
Object: Given a maximum solar cell size of 1/2 x 2-1/2 inches (1.25 square inches or 8.06 square cm), make a self-starting 6 inch robot dragster to race one meter in full sunlight (or 500 Watt halogen equivalent). Competitors will race each other in round robin eliminations along 6 inch wide lanes. The fastest finisher wins.
Class A: Racing occurs on a sheet of level glass.
Class B: Racing occurs on equal but rough terrain.
Contents of this page:
Competitor Design Parameters: Solaroller
1.At the start of the race, the competing Solarollers potential energy must be zero (0) volts. To insure this, solarollers must have an effective switch or contact pair that when touched or shorted, clamps all on-board power storage to zero. Solarollers can not use any other energy source to motivate them than what they are able to draw from their solar cell. No pre-tensioned springs, elastics, combustion or compressed energy sources are allowed, though any of these may be employed in the design so long as it can be proved that they are at a complete state of rest at the beginning of the run.
2.Robotic competitors cannot initially exceed the bounds of a 6 inch cube. Competitors may split apart or change their physical geometry beyond the dimensions of this cube during a run, but a win will only count when the LAST part of a Solaroller has crossed the finish line. Competitors are not allowed to drop, throw or leave behind any part of their chassis. Competitors must finish with everything they started with.
3.Competitors cannot have parts removed or added to them between races with the exception of replacing broken components necessary to the operation of the vehicle.
4.The maximum allowable solar cell surface area cannot exceed 1.25 square inches (8.06 square centimeters). A 2 1/2 x 1/2 inch, 3 volt amorphous cell (as is commonly used in a variety of solar-cell calculators) shall be considered the norm. Any solar-cell configuration will be considered valid so long as the effective cell area does not exceed the maximum allowable. Any solar cells found in violation will have black tape applied to bring it into specification. There is no minimum solar cell size restriction.
5.During racing, competitors must not physically touch or attempt to touch each other, however, competitors may attempt to interfere with each others light source by extending vanes or other devices over the one inch lane walls. Vane extensions must still fit within the size guidelines.
6.Designers are not allowed to augment their competitor performance by the use of external light sources, lenses, mirrors, or even subtle reflections off of watches or eyeglasses. Devices must work over the 1 meter travel distance from a minimum light source of one 500 watt halogen light placed 18 inches above the race platform, to a maximum of up to three such halogens, to pure noon-time, unobstructed sunlight.
7.Competitors should be able to withstand heat excesses up to a radiant 122 degrees F, (50 degrees C) from the competition light sources.
The Competition Platform
Class A Racing:
The racing strip is composed of two side by side 1 meter lanes of clean, smooth, level, glass mirror with 1 inch high x 1/2 inch wide arborite walls along both sides of each lane. The lanes will have exactly 6 inches between wall surfaces along the full travel length. Competitors start in a 6 inch square with their forward edge pushed up to the inside edge of a thin black starting line drawn on the walls and mirror surface. Exactly 1 meter away from the start line is the finish line which the roller must cross completely. The finish square is also 6 square inches and has no end wall (though a floor beyond the 6 inch finish square is not guaranteed).
Due to heat distortion, the walls cannot be guaranteed perfectly straight.
The light source for the table will be positioned so that no shadows fall from the sides of the vertical walls. Competitors will race into the light source and must be able to optimize a light source from perfectly vertical (90 degrees) to a late afternoon angle (30 degrees). Light may be limited by a single clear window, but otherwise should be unhampered. Should the sun fail to shine on the day of competition, a (minimum of one) 500 watt halogen light source will be used set at 18 inches above the dead middle of the racing platform. The light incidence shall be directed at the very center track wall, and efforts shall be made to avoid excessive heat buildup where possible (consequently it is advised competitors not use hot glue, soft, black plastics, or wax to hold their solarollers together. Melting has occurred on occasion).
Class B Racing:
Class B racing differs in that the racing strip is two equal lanes of various rough terrain, including, but not limited to, 1mm ball bearings, sandpaper, 1/8th inch rods, loose sand, and small rocks. No obstacle shall be larger than 1/8th inch high. As well, the racing strip may be inclined lengthwise up to +/- 10 degrees from the horizontal. The vertical incline shall remain level at all times to guarantee an equal race between competitors. Light sources are as specified for class A solarolling.
The Class B race is to promote the design of solarwalkers. That is, capable, terrain handling machines made from modified walking toys or other innovative designs. Rough terrain means that competitors can not just trust inertia to win the race. In some cases, power must be used wisely to overcome obstacles. Legged creatures have an advantage as they can step over most barriers without difficulty.
Of course, walking is not the only solution, but limited power and the quality of most wind-up walkers makes it practical. Furthermore, for those electrically capable but mechanically deficient, modifying a wind-up is sometimes a much easier task than starting from scratch (see Roboart/Modified Appliance chapter later this Guide).
All other rules for device dimension, power, and racing apply.
The Race
The single-heat race begins when the judge says "go" and lets a charge build up in the two competitors. This is done in one of two ways; either a conductive knife blade is removed from the competing solaroller capacitor terminals, or pressure is removed from an optional designer-supplied switch to remove any "sprint" charges still remaining in the device. Care shall be taken to insure that competitors are released fairly and with as little disturbance as possible. In designs where the aforementioned does not work, an alternate method of starting must be worked out with the judges. It is, however, the designers' responsibility to insure that a clean start can be managed.
Once the contacts are open and the devices allowed to charge, the race has started. To insure the devices follow the "self-starting" rule, competitors must remain immobile for at least 2 seconds following the start of the race. If one or both move within that time, a false start is called and the race is re-run. If it happens again, then that competitor's designer has the option of removing the device for modification to re-race later, or moving the competitor back so that it does not cross the start line before two seconds are up.
The race is run until the backmost vertical edge of a competitor crosses the finish line at the end of the 1 meter lane, until a designer concedes, or until a full 2 minutes has elapsed.
During the run, competitors are allowed to touch the surrounding walls as necessary but should not damage or climb the walls. Any competitor that stalls or binds against a wall shall be left untouched until the progress of the other competitor is determined. As soon as the other competitor has caught up without binding, that competitor shall be declared the winner of that heat. In the case of a dual stall, the competitor the farthest down the lane way shall be considered the winner of that heat.
If clear, unobstructed sunlight is available or the halogen light option is used, the times of the individual runs will be kept track of. All running times shall be registered and recorded.