# Catch Mine Drift 2018: Rules

The Catch Mine Drift project requires student teams to build a device that can move independently through an enclosed passage. The device must be self-contained and fit within the two doors that form the starting area. Once the inner door is slid open, the device must move independently through the passageway without any user intervention or assistance.

Teams will be given up to 4 minutes to set up their device and make as much progress as possible. Marks will be assigned based on forward progress.

## Construction

Each device must be designed and constructed according to the following rules:

1. Device must operate independently without student assistance or intervention.
2. The device must fit between the two doors that form the starting area.
3. The following power sources are not permissible: compressed gas canisters, chemicals, explosives. Electrical power is permitted through the use of batteries only.
4. ALL valid parts must be sourced from an approved list of Canadian suppliers and be accompanied by a link to the Canadian website which lists the price in Canadian dollars. The inclusion of any non-standard parts will result in a 15% deduction from your combined score. Be careful that the American version of a website is not used accidentally (e.g. http://www.lowes.com instead of http://www.lowes.ca). The approved list of websites includes:
5. Items need not be purchased from the supplier listed; however, they must have a Canadian supplier as described above.

## Performance competition guidelines

All performance testing will proceed according to the following steps:

1. Prior to testing, each team will be required to bring a printed copy of their itemized cost analysis of all the parts used in their device. There will be a 5% deduction to your cost score for failing to bring a physical copy of the analysis sheet.
2. The TA will review your cost sheet against your design and request additions or changes as needed. No changes may be made to the design after this point.
3. The device will be photographed.
4. Students will load their device into the starting area with the inner door closed.
5. The device must be able to fit in the enclosed starting area. The outer door may be closed to verify that this size constraint is met.
6. Once loading is completed, and sizing is confirmed, the outer door may be left open.
7. The inner door will be slid opened and the device allowed to progress through the passageway. One team member may turn the device on, if needed, with a single hand. If so, that same hand must be withdrawn and used to raise the inner door.
8. The device will receive one point when the front-most portion of the device passes a progress line. It will also receive a point for when the rear-most portion of the device passes a progress line. Because the front and rear are expected to progress at an equivalent rate, the front of the device can only score up to one more point than the rear.
9. Scores will determined based on maximum forward progress in the event that the device slides or moves backward.
10. Teams may complete up to a maximum of three attempts in the allotted time. Only the maximum score will be used. If time expires in the midst of an attempt, only points earned to that moment will be counted.
11. Teams are responsible for uploading an electronic version of the cost analysis sheet. There will be a 10% deduction to your cost score for not submitting the document by the specified deadline.
12. Problems or issues not expressly covered by these rules may be treated or penalized at the discretion of the instructor.

## Cost calculation

The cost of the device is determined as follows:

1. Costs must be calculated using the list price on an official website, regardless of the actual purchase price. Nothing can be free. Everything must have a cost.
2. Item costs and calculations should be reported rounded to the nearest penny (i.e., two decimal places).
3. All taxes should be excluded from calculations.
4. Where items are sold in packages of two or more, the item cost may be calculated as a fraction of the total. For example, 3⁄4” #10 wood screws are sold in packages of 75 for \$4.57. Therefore, the cost of three screws is:
$\text{cost}=\left(\frac{\text{3}}{\text{75}}\right)4.57=0.18$

after rounding to the nearest penny).

5. The cost of wood or other material may be scaled based on the number of usable parts that could be machined from a given raw piece of material. This is different that the area or volume of material used.
6. Costs of consumables such as tape or glue may also be prorated based on the length or mass of material used.
7. The costs of tools should NOT be included in the analysis.
8. Cost analyses not submitted according to these rules are subject to a 15% deduction to your cost score.

$\text{performance grade}=50%\left(1+\frac{\text{[your score]}–\text{[lowest score]}}{\text{[highest score]}–\text{[lowest score]}}\right)$ $\text{cost grade}=50%\left(2–\frac{\text{[your cost]}–\text{[lowest cost]}}{\text{[highest cost]}–\text{[lowest cost]}}\right)$
$\text{performance grade}=100%×\text{min}\left(1,\frac{\text{[your score]}}{\text{36}}+0.25\right)$ $\text{cost score}=50%\left[1–\text{erf}\left(\frac{\text{[your cost]-50}}{\sqrt{\text{2}{\left(\text{15}\right)}^{2}}}\right)\right]$