Build a mechatronic device capable of properly covering one half of a roof surface with shingles.
A footprint of 4 ft^2 instead of 2'x2' is permitted, but the design should not depend on the robot's being able to span the full width of the roof, since that is not realistic for actual roofs. Put another way, the robot should be able to lay down shingles horizontally without depending on being as wide (or as high vertically) as the roof surface. Within that qualitative description, making one of the robot's footprint dimensions larger than 2' is allowed.
You may use wall power, but must use a dedicated supply (such as a PC power supply) for the final product. Battery-operated devices are another possibility for greater mobility. You may not rely upon the laboratory bench power supplies to run your device.
A guideline reimbursable limit for the total parts and materials cost purchased by the team is $500; however, each team will create a proposed budget and negotiate a final reimbursable project cost with the instructors. The $500 limit does not include the cost of a nail gun, and possibly other high-expense items, which will be reimbursed separately by Kent McElhattan, President of Industrial Scientific. NO SALES TAXES will be reimbursed. At the end of the semester, the instructors keep all parts supplied or
reimbursed. These will be available for students in succeeding years.
Construction and Aesthetics
The device must be robustly constructed. Nuts and bolts or other proper fasteners are generally preferable to tape, especially large amounts of the latter. For electronics, use proper soldering or wire wrap for connections. Prototyping electronics on a bread board is fine, but the final project should not include a bread board. Appearance counts. “Rat’s nest” wiring, duct tape, bubble gum, or otherwise rickety-looking devices are discouraged not only for the sake of aesthetics, but also because they tend to be less robust.
The mechanism may not damage anything with which it interacts. The sole exception is the need to nail the shingles to the roof surface, which could be viewed as a type of damage. If you use a nail gun, do not disable any of its safety mechanisms. The instructor team will create specific safety procedures for testing with a nail gun and eventually add them to this document. While creating your system, be particularly careful with soldering irons and the manufacturing machines in the machine shop, even if you are an expert on operating them.
1. General Requirements
- Cover a portion of the half-roof with 1’x1’ shingles using the conventional overlapping pattern with ½ shingle row-to-row offset.
- Maintain a ½” “cutout” gapping between shingles in the same row.
- Attach the shingles using roofing nails with 2 nails in each shingle. You should aim for the nail positions shown in Figure 1, but some deviation from these positions is acceptable.
- The robot must not fall off the roof.
2. Setup & Input
- The following will be provided to the teams: shingles, roofing nails, nail gun (if desired), plywood half roof, horizontal chalk lines, roofing felt.
- The user may make the initial emplacement of the robot along the roof edge and load the shingles at the start and during the operation, anywhere along the roof edge.
- Vertical spacing of chalk lines will be between 5” and 5.5” (see Figure 2), but the machine should not assume a particular value.
- Initial emplacement of the robot should take place in less than or equal to 1 minute; the loading of the shingles into the robot must be completed in less than or equal to 30 seconds
- Minimum roof pitch is 4/12 (18.43 degrees)
- Attach 7 shingles in 3.5 minutes. (7 shingles together weigh ~ 9lb.)
- Nail guns come with an in-built safety feature. Do not defeat this safety feature on nail guns.
- Include an emergency kill switch on the machine. If the machine gets jammed, use the emergency stop. Locate the kill switch such that it is easily accessible using your hand.
- The instructors will create an emergency stop method for the compressed air supply to the nail gun, if used
|Figure 1. Nailing Positions|
|Figure 2. Chalk lines on roofing felt|