ME

72

Critical Design Review (CDR)

Due
Tuesday, Dec. 4, 2007

(time
to be scheduled for each team)

(worth
20% of your overall grade)

In
any large system engineering project, the next major step in the design process
after the Preliminary Design Review (PDR) is the Critical Design Review (CDR).
The CDR is the final check before the main fabrication, testing, and
demonstration processes start.  The
goal of the CDR is to determine if the system design architecture and component
designs have a high likelihood of meeting the initial design requirements.  By the time of the CDR, a design team
should have made all of the major design decisions about the system
architecture, and should have completed enough analysis (and perhaps mock-up
prototype work) to ensure that the proposed design can meet its goals.  While the goal of the PDR was to assess
if you have a viable concept, the goal of the CDR is to ensure that your
concept can be engineered to meet its goals.

Just
like the PDR, the CDR will be conducted in 20 minute sessions with the course
instructors (on Thurs, Nov. 29, 2007).  During these sessions we will review
your designs and analyses to ensure that you have enough understanding of your
system’s potential to meet the contest guidelines and to successfully compete.

For
the CDR you should prepare at least
the following:

·
An Overall System
Architecture Diagram. Describe visually the architecture
of your overall system, indicating all of the major components.

·
Design diagrams of all the
critical components. Each important component (e.g.,
latches, folding mechanisms, winches,
servo mountings, glider wings, etc.) should have an associated sketch or
diagram that clearly shows all of the components and their roughly estimated
geometry. Your diagrams should be detailed enough so that it would take only a
small step to turn the diagrams into shop drawings.

·
Parts list cross-matched
with the design. You must guesstimate the type and
amounts of the contest material that will go into each component.  From your list we should be able to
determine if you can build your design within the contest material constraints.

·
Detailed Performance Estimates and Analyses. You should estimate how much energy
will have been transferred to your flying/projectile device at launch time, and
the sources of the energy (stored mechanical energy, motor energy, and/or
gravitational potential). Based on this energy estimate, and the nature of your
flying or projectile device, you should have an estimate of its southerly
landing distance. Please summarize the calculations in a digestible form, with details
of your calculations relegated to appendices.

We will grade your CDR as follows:

·
Completeness of the design—are
the designs of all the key components at a sufficiently precise level of detail?  Could someone take these drawings and
develop detailed shop drawings from them without too much effort?

·
Completeness and quality of the performance
analysis. Do you have a good estimate of the amount of energy you will
be able to impart to your device at launch?  Have you estimated how far your device
may land in the southerly direction?
Is your model and estimate of the flight performance realistic, and do
you understand the limitations of your analysis?

·
Can your design be built from the contest
materials?

·
Is your design robust enough to
withstand repeated testing and competition?