Unformatted text preview: ments.
does this experiment fit into the study of the process or system?:
(a) Because of tool geometry, x-axis shifts would be expected to produce thinner
blades, an undesirable characteristic of the airfoil.
(b) This family of parts has been produced for over 10 years; historical experience
indicates that externally reground tools do not perform as well as those from the
“internal” vendor (our own regrind operation).
(c) Smith (1987) observed in an internal process engineering study that current
spindle speeds and feed rates work well in producing parts that are at the
nominal profile required by the engineering drawings - but no study was done of
the sensitivity to variations in set-up parameters.
Results of this experiment will be used to determine machine set-up parameters for
impeller machining. A robust process is desirable; that is, on-target and low variability
performance regardless of which tool vendor is used.
Figure 3. Beginning of Guide Sheet for CNC-Machining weight of precipitate as a function of catalyst may be
near zero for the selected low levels of catalyst and
near maximum for the high levels.
2. Should capture, as much as possible, a quantity
or quality of interest for the experimental unit. For
example, if the experimental unit is an ingot and a
response is T = temperature, it may matter whether
T is taken at a single point or averaged over a surface
region, the entire surface area, or the entire ingot
3. Should be in appropriate units. The units may be absolute, such as pounds, degrees centigrade, or
meters. They may be relative units, such as percent
of concentration by weight or by volume or proportional deviation from a standard. What is “appropriate” may be determined by an empirical or firstprinciples model, such as using absolute units in E
= mc2, or it may be determined by practical limitations, such as using percent of concentration by
weight because the experimental samples are not all
the same weight.
4. Should be associated with a target or desir...
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- Fall '14
- The Land, response variable, Technometrics, guide sheet, david e. coleman