Full Contest Description

This quarter’s robot contest is inspired by the Mayan Ball Game combined with March Madness Basketball! The Mayan Ball Game is one of the Mesoamerican Ball Games and inspired the MAE3 Fall 2007 Robot Contest. The Mayan Ball game was the first team sport in human history. The game was played in large courts such as the one adjacent to the Chichen Itza pyramid. March Madness takes over the lives of many college students in early Spring. Through in-depth archeological studies of Central America and anthropological studies of the modern day college student, MAE3 tutors have simulated what would have happened if Mayan’s had a Spring break. The Mayan ball game was played in large courts, known as Pitz, and points were scored by shooting the ball through the hoop, as shown below.

Mayan Ball Court (Pitz)

Hoop

In the robotic interpretation there are two sides to the playing field, and robots compete head to head, each starting on a different side of the table. Orange balls begin on the pyramid, with a gold ball placed in the temple atop the pyramid (note the Mayan alphabet on the temple spelling MAE). Behind each robot is a scoring hoop, and a scoring court, known as a Pitz.

MAE3 Playing Field

Points are scored by bringing balls of off the pyramid and into scoring locations on the field. Scoring is as follows:

Scoring Arena

· 1 point for every orange ball placed in Pitz (courts behind the starting positions)

· 2 points for every orange ball placed in rim area (or above it)

· 4 points for every orange ball through the hoop

· Gold ball:

· 15 points for Pitz

· 30 points for rim area

· 60 points through the hoop

· Gold ball on ones side of the court is also the tie breaker

Each MAE3 design team will build a robot that will compete head-to-head on the contest table. The robots will be arbitrarily assigned to start in either the right or left starting areas. The starting size of each machine is limited to a cube of 10”x10”x10” and must fit unconstrained (i.e. not touching the sides) of the test cube. Before the beginning of a contest each team will have to setup their robot within a 2 minute time limit. The contest will run for a 1 minute time period.

There will be four playing fields built to accommodate all students in the class, and manufacturing tolerances will results in small variations between the contest tables. It is the design teams responsibility to develop a robot that will work on all contest tables.

Each team will build a machine using the kit parts described below to perform the task. The kit will include 5 DC motors (2 will have gearboxes) and one solenoid. Electrical power will be provided from a power supply with a maximum of 5VDC output. The power will be controlled by the following switches:

· Two 5 Volts DC switches

· Two variable voltage switches. Note, the maximum current output is less in these switches. Since DC motors draw high current when they are not rotating, two non-geared motors may not start simultaneously if they are tied to the variable voltage source!

Each switch is Double Pole Double Throw (DPDT) switches, which can operate a DC motor in either direction. Note the kit contains five DC motors and one solenoid, but only four user controlled switches. More than one electrical device can be connected to a single switch, but the voltage may drop if a large current draw is placed on the power supply. Use of motors, solenoids, and switches will be covered in lecture and is described in the Mechanical Device textbook.

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Contest Event Description

The contest will be held during the MAE finals period and will be open to the public. The contest will be held in a single elimination fashion (like a tennis tournament). During the lab period of the last week of classes, each section will hold a section-wide contest. The results of this contest will be used to seed the placement of the final contest. Thus teams that perform better during their section contest will have statistically easier contests in the early rounds. Since the number of teams in the class will not be exactly a power of 2, the higher seeded teams may get a "buy" during the first round. If necessary random numbers will be used to ensure a proper contest pyramid.

Performance in the contest depends on numerous factors that do not relate to engineering quality of the robot, including driving skill and luck! The grade for the project will not be adversely affected by poor performance in the contest, but will be based upon:

· Ability to achieve to design objectives selected by the team, and performance of the machine without an opponent.

· Effective communication of the design (orally and in final reports).

· Documentation of the design process and justification of decisions made.

· Analysis of machine performance.

· Following good design practices.

A trophy will be presented to each member of the winning teams, and a number of machines will be selected for display in the Design Studio and MAE Department. Team members must work out among themselves who will keep the final machine (after their display period). Teams may post presentations and video of their robot on the class web page, which they can cherish forever.

Contest Rules

Only the tools and machine equipment in the Design Studio can be used to build the robot.

Energy Sources: The energy used by the devices in the competition must come solely from:

Potential energy derived through a change in altitude of the center of gravity of the machine;
Potential energy achieved by the deformation of the Springs provided by the Kit;
Electrical energy derived through the umbilical during the 60 seconds when the power supply is energized.

Size: At the start of each competition, every part of the machine must fit unconstrained, inside the 10”x10”x10” starting area, whose base is completely aligned with the marked starting area on the playing field.

Umbilical Cables: The electrical connections will made to a single umbilical cord hung from above the table; one on each side of the table. The umbilical cord cannot be touched during the contest, and there will be some drag from the cable. Each machine must be designed to overcome this drag if necessary for motion of the machine. If requested a TA can ensure that the umbilical cable does not snag.

Detailed Rules

1. Judges and/or instructors will disqualify any device that appears to be a safety hazard.

2. Any machine that has flying parts must notify opponents, and all contestants must wear safety glasses during the machine operation.

3. If a projectile is used, for reasons of safety, it must have a frontal area greater than 2 inch squared.

4. Contestants will randomly be assigned to start on either side of the playing field.

5. A maximum set-up time of 2 minutes will be allowed at the contest table.

6. A maximum of 1 minute will be allowed for removal of all parts of each machine after each contest.

7. Operators may interact with their machine during a contest only through normal operation of the switch boxes (for example you cannot touch the machine with one's hands during operation).

8. It is allowable to adjust the configuration of the machine between contests; for example adjusting the configuration to the side of the playing field the machine starts on.

9. Each machine can only interact with the surface of the playing field and objects on the playing field.

10. The judges will wait until all the playing pieces have stopped moving before determining the winner.

12. Points will be awarded based upon the final location of the playing pieces, regardless of which machine moved them.

13. A playing piece will be declared out-of-bounds if it is off the playing field.

15. Damaging the playing field or the control boxes may result in disqualification.

16. Purposefully using the electrical cables for any purpose other than transmitting electricity is not allowed.

17. Gaining traction by use of adhesives, or by abrading or breaking the surface of the playing field is not allowed.

18. A machine may not contaminate with lubricant or other substance the playing field or an opponent's machine (internal lubrication of a machine is permissible).

19. Kit materials may not be changed chemically. DC Motors may not be rewound.

20. The paper that is attached to the acrylic in the kit cannot be used as a separate element in the machine. If any piece of paper is detached (even partially) from the acrylic it must be discarded.

21. The insulation must remain on the electrical wire in the kit except where the wire end is attached to another component, and there up to 0.5” of insulating can be removed.

22. The clear acrylic 0.25 thick is for testing. If you include any of this acrylic in your final machine, you must remove an equivalent amount of colored acrylic that was used in making the part.

23. Spare parts are available on a limited basis. Students should go to the tutors of their section to receive replacements for parts broken. Student can purchase replacement acrylic from upper campus machine shop or off campus (see Chris Cassidy for sources)

24. Machines may be designed to interact. However, it is not in the spirit of the competition to intentionally damage another machine and no part of the kit may be used in a manner that is intended to cause harm. Any device which is designed to chop, break, or penetrate another machine will not be allowed to compete. If you think your machine may be at risk for violating this rule, ask early before you build it! (see rule clarifications)

25. Machine advertisements and decorations must be of the nature that it does not offend any other students or audience participants (use common sense!).

26. All rulings of the judges will be final.

Any modifications or clarifications to the rules or kits will be posted on the class web page.

Clarification to Contest Rules

Applying forces onto an opposing team’s robot that are large enough to break plastic pasts, while the opposing robot is in its starting area, will be deemed to be intentional harm to an opponent and can lead to disqualification.

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Kit Parts Rules

Each machine must be constructed solely from materials provided in the Kit listed below, i.e. one cannot substitute a 12"x16" piece of acrylic with a 6"x32" piece.

If a part of the kit is damaged it can be replaced from the scrap pile, as long as the design team can show that they could completely rebuild their machine solely from the kit.

In addition to the kit parts listed in the table, the following items may be included in the machine:

· Nuts, bolts, and washers included in the Design Studio bin. These include bolts from size 2 to size 10, and metric screws for mounting the motors.

Only take nuts and bolts from the bin as you need them, and search through the spare bolt bin before taking more (we went through $1,500 in fasteners last year!)

· Fasteners can be used only for fastening purposes, and thus must fasten at least two other parts together.

· Adhesives; including hot melt glue, and acrylic adhesive.

· Tape used ONLY for electrical insulation

· Lubricants used only to reduce friction.

· Nonfunctional decorations.

Replacement Material Policy

We have some extra material that can be used for experimentation. This material will be made available in the lab scrap bins. In addition each section tutor has access to a limited amount of replacement material for their section. If you need replacement parts, contact your tutor. Some replacement of "mistakes" made to kit parts will be available, but supplies are limited, and replacement is not guaranteed.

Kit Part List and Motor CAD Models

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Frequently Asked Questions (FAQ)

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