The 2.810 group project this term will consist of the fabrication of "N" radio controlled cars for each group of N students. You will start with the following list of materials per car.

* four foam rubber tires (choice of 3 sizes)

* front steering assembly components

* rear wheel assembly components

* electric motor + 2 sets of batteries per group

* one radio controller per group

( including steering servo and speed control)

and one battery charger
 

The group project will consist of the fabrication of the body shell, chassis and wheel hubs and the final assembly of the car. The aluminum chassis can be made by either sheet metal forming or sand casting. Fabrication by sand casting requires the design and machining of a casting pattern. The pattern will be taken to a local vendor, who will perform the casting. Fabrication by forming can be done in Building 35. The shell and wheel hubs will be thermoformed and injection molded respectively, using tooling provided by Gerry Wentworth. The performance of the cars will be evaluated in a contest on the final day of class. The contest includes the driving of each car (all group members participate in driving) around a designated loop on flat, carpeted floor (see figure 1) and the disassembly and assembly of the radio controlled unit into each subsequent car. There are N_max laps and N_max pit stops). Cars are limited in size to 12"X18"X12".

1. Design

Each group must design their cars for assembly and disassembly of the radio control unit during the race. No modification of the radio control is allowed. All assembly must be made by mechanical fastening only. Glue, adhesives, tape, Velcro or similar products are generally not allowed. All requests for clarification of the rules, and decisions will be made by email so that all results are made public instantly.
 

2. CAD/CAM/CNC

The fabrication of the radio controlled car chassis by sand casting requires the design and fabrication of a casting pattern. This will be done using MasterCAM (ver 7.0) software. A special lecture will be given by Gerry Wentworth on the use of this software, including the drawing of the chassis, the generation of tool paths and the down loading to the Cincinatti-Millicron 3-axis Milling Machine. Additional learning of the software and demonstrations on the milling machine, thermoforming machine and injection molding machine^* will take place after class hours. There are eight MasterCAM stations in room 35-135 and an additional station in Building E40. The building 35 facility is shared with the 2.008 class, but is open to you (with the appropriate password) 24 hours a day, seven days a week. It will be required that all members of 2.810 submit a MasterCAM drawing for the chassis, however, only one drawing per group will be machined and used in the sand casting process. For those groups that decide to form their chassis the MasterCAM homework is still required.

Sheet forming of the chassis will require using SolidWorks or some other CAD software. SolidWorks ( a tutorial is provided for you) will convert your design to a flat drawing. The flat drawing will be loaded into the waterjet (as a dxf file) and cut. Bending and additional operations will be performed on the presses and other equipment in building 35.
 

3. Group Organization

An important aspect of this project is that you organize yourselves in groups and carry out the projects in a cooperative and productive manner. In fact, your first assignment will be to form into groups ( which this year will range from seven to eight) to carry out this project. Your responsibilities in the group are to develop your car design, competitive strategy, and manufacturing tasks as a group. Your first assignment is to find a mutually agreeable one hour time period per week to work on this project. We are interested in knowing, how well your group functions, how the work load is distributed, and how you dealt with problems and conflicts. This information will be reported in your final report and group progress reports. (Past experience has shown a very strong correlation between well functioning groups and a successful physical product.) The group should designate a "secretary" to record important decisions and problems and to prepare the group progress reports. You will need to record your organizational structure, the evolution of your design (using drawings and design ideas), the division of tasks etc. for your final report.
 

4. Physical Product

The most important aspect of this project is that your group successfully complete the assembled cars using the various manufacturing processes. You will be required to build N cars for a group of N people. After the contest one car will be left with the instructors for grading. The car will be returned in about one week. The car should demonstrate good design and manufacturing technique, with the aim of demonstrating a satisfactory performance in the final race and assembly contest. Each group will receive a letter designation i.e. "A", "B" etc. which, along with the car number, must be prominently displayed on all cars during the race (i.e A1, A2...) By the way, the winners of this contest will win the coveted 2.810 CAD-CAM-"CAH" award ( as in "pahk yah cah in havahd yahd").
 

5. Report

A short report is required to accompany your car on the day of the contest. The report should include;
 

1. A photo of your car

2. A list of group members and photo

3. Design drawings (engineering quality) for chassis and assembly

4. Tasks performed by each group member and a rough estimate of the total group man/hours devoted to this project.

5. Time estimate in seconds for the disassembly/assembly as will be performed for each pit stop during the race.

6. Group strategy and comment on the functioning of the group.

7. Very brief discussion of the key design and manufacturing issues which your group had to deal with, and what lessons were learned.
 

Please try to acknowledge the sources of ideas your group used and give proper references ( as you would see in a technical paper ). The text of this report should be written in the spirit of an executive summary. Please use 12 point Font, adequate margins (at least 1") and 1 1/2 spaces. Do not exceed 6 pages of text (not counting photos, drawings, & tables). No appendices are allowed.
 

6. Grading

Each of the group projects will be graded as a group, that is, one grade will be assigned to the entire group. Therefore, it is the group's responsibility that each member contributes equally. The grade will depend primarily upon the physical cars and the effort demonstrated in producing it. Quality of manufactured parts, fit and finish and performance of the assembly and disassembly scheme as judged by the instructors will all be considered in the grading. In addition, performance in the contest on the final day of class will also be considered. The final report describing the cars and the group effort will contribute about 10% of the project grade. Overall the project will count for 40% of your grade and the two quizzes will count 30% each. Significant extra credit will be given for class participation (up to 5%). All quizzes are open book, open notes.
 

7. Project Schedule

Key dates for the 2.810 project for the Fall 1999 are:

Sept. 13 or 15 - MasterCAM Lecture

Sept 29 - Pattern Design Discussion

October 25 - CAD chassis Drawings

October 25 - Pattern Machined for Foundry (this week)

October 25 - One paragraph written report on the group

November 1 - Schedule Casting for this week or before

November 10 - Oral Progress Reports

December 6 - Contest Preparation

December 8 - Contest