Project Planning and Management

The Robotics team started the program with organization in mind and communication as a priority. Beginning in mid September, individual committee captains were chosen to be the leaders of Construction, Table Display, Notebook, and Sales and Marketing. These four key people were able to recruit the eventual 70 student members of the Robotics team. Before the general meeting took place, each prospective member filled out a form so that demographics and contact information could be recorded and used for effective communication. The information gathered from these forms was then compiled into a spreadsheet using Google Spreadsheets, which team leaders later used to keep record of attendance and participation. The majority of Robotics announcements were sent via e-mail. All team captains and sponsors had access to a gmail account and each group’s members from dhsrobotics@gmail.com. In this way, the team as a whole could be in constant contact with the “base of operations.” Groups were set up by committee to make it easier for captains to communicate with their committees.

The brainstorming process encompassed three design components: the claw, motion, and reach. Designs were shared by using Smartboard technology, so that ideas were easily expressed and modified through a group effort.

  1. Claw - The initial design involved a multiple delivery clothespin idea. The second design incorporated a clothespin with a mousetrap-imitation style. The mousetrap design was not feasible because the actual function would not score. Therefore the construction team reverted back to the multiple delivery clothespins.

  2. Movement - The first thought was that four wheels driven by two motors in the middle would be the most efficient approach. Then, the team decided that the lattice would require the large motor, which resulted in the need for only one large motor. From that, the team came up with a fixed axel design in which one motor turned a fixed axel and wheels on both ends. To steer, one member of the team researched and built a  rack-and-pinion steering. He used a model of a radio-controlled car to thoroughly study the mechanics. When prototyped and tested, it was discovered that this idea was not feasible. The chassis dragged the rack-and-pinion and the turn was not effective. Physics research was needed to find out how much torque would be needed for the operation of one large motor. The construction team initially built the chassis and motor with a fixed axel and measured it with a spring scale to find the required force needed to carry twenty-four pounds. After determining the needed force, the rack and pinion steering was tested. Unfortunately, the rack and pinion was not operational because it was dependent on a single axel. One of our mentors observed that with out a differential, which allows one wheel to turn in a different speed from the other, steering would not be possible. Jordan Steelman came up with the idea simulating a child’s tricycle. It involved only one motor and two freely spinning wheel. As a result, the two forward wheels could be moved closer together, removing the need for a differential. The materials from the former rack and pinion were used as the rear wheels. In this manner the tricycle design was created. Several designs were suggested for steering of the “tricycle” including one with the steering pivot behind the wheel and another with the pivot above the wheel (seemed most feasible).  With two weeks left until the competition, the majority of the construction committee was unwilling to start a redesign. Veteran members convinced others that the best plan was to commit a large motor to each wheel and use a small motor for the lattice. Once rubber bands and bungee were used to support the weight of the scissor lifts, the group followed the advice.

  3. Arm - The team’s first idea was to use a telescope-like design, consisting of a three-piece folding arm. Because this initial design limited the distance that could be reached while the arm was collapsed, brainstorming changed to focus more on a double “lattice” design. Knowing that the PVC required for the lattice would be heavy, we decided to use bungee stretched between the pivots. The idea was that it would be neutral and a motor could vary easily drive it up and down. Calculations were made to determine the exact number of lattice pieces that were needed to meet the height of the clothesline. The prototype made use of ¼ inch threaded rod for the center pivots, but it was soon discovered that this method used too many materials and wooden dowels replaced the rod.  In the early stages the lattice was entirely made up of ½ inch PVC piping, but eventually it was made of 8 20-½ inch pieces of ½ inch PVC and 4 20-½ inch pieces of ¾ inch PVC. So that each piece of PVC pipe had exactly the same cut and could face the same direction, team members constructed a custom gig for the drill press.  Originally, team members believed that bearings would be the most efficient because they spin easily with little or no friction. It was soon ascertained that mounting of the bearings would be difficult, so holes were simply drilled instead. Throughout the design of the prototype, engineers decided to adapt the angle of the attachment due to the physics of force vectors, for a more efficient pull. The design for the movement of the lattice went through several stages. The initial design included the Igus chain along a straight path beneath the lattice. A motor would be attached to a gear whose teeth would catch the holes in the chain and push the chain horizontally. To get a gear, the team researched spur gear design. When we got a design together, we had the gear drafted in AutoCAD. It was printed on cardstock and traced onto 3/8” plywood and then cut out on a band saw. When the prototype was built, the gear did not meet the holes in the chain. It missed or jammed. Also, the small motor was not powerful enough to drive the gear. Before abandoning the gear idea, several team members researched the idea of putting two motors on the same speed controller and reversing the polarity of the motor so that it could double the torque on the gear. After building the mounts for both gears, they found that the studs of the gear did not line up. This idea ran out of time at Mall Day. When they tested the lattice at Mall Day, they decided to use a spool of braided string to pull the lattice down. They relied on the rubber bands and bungee to drive the lattice up. They mounted a motor on the underside of the chassis with a spool mounted to a small motor. As of the completion of the Notebook, this problem was not yet resolved.

PROMOTION

            Davidson’s Robotics team took advantage of many opportunities to promote the robot, MACHO and BEST. Through the creation of a Sales and Marketing team, the team was able to produce an infomercial to conveniently advertise the robot on the day of competition. Early in the process, the team decided to base the video on the same format as the usual infomercials seen on television today. In addition, the team decided to follow in the tradition of the past DHS teams and design a team t-shirt. Members gave input and suggestions on the initial t-shirt designs through email. Most of the team members also took part in the BEST sponsored Exploreum Day. The members that participated were able to further discuss designs and socialize while watching the Mission to Mars IMAX film. Later, members of the engineering and table display visited Government Street Baptist School to educate the elementary school children on careers in engineering, what engineers do, and how they can help Davidson succeed in building an award winning robot.

SPONSORS AND FUNDRAISING

            In order to purchase the supplies needed for an impressive table display and operating prototypes, the Robotics team needed additional funds. Through the sponsorship of corporate businesses, school fundraisers, and parent donations. Thanks to the team treasurer, detailed record keeping allowed the team to keep up with monetary gains. Prior to Kick-Off day, each Robotics team member donated a case of coke products to be sold to other teams. In addition to the sold beverages, the team gave away huggers expressing Davidson’s encouragement of the other teams. Over the next six weeks, the remaining coke cans were sold to Davidson’s students for the Robotic’s team profit. Exxon Mobil Volunteer Program; parent, Mike Jones; and the local business, Petrie’s were just a few of the appreciated sponsors that supported MACHO. To cover the potential cost of competition and travel to Auburn, the team will use a donated popcorn maker to sell popcorn and cokes to competition participants on game-day. Thanks to these donations and fundraising efforts the table display team was able to cover its largest obstacle- money.