MICRO METROLOGY | CASE STUDY
<< Figure 3: New drill bit off production line. >>
<< Figure 4: Same drill bit post drilling sequence tribology test. >>
The result of this combination of features enabled the NPFLEX to perform repeatable multiple measurements on multiple drill bits even from end-on angles. Metric surface dimensional data was rendered easily into standard reports (see figures 3 and 4). This gave the manufacturer a metric measurement capability that was objective and comparable through time. The issue of user dependence is minimised, allowing the company to focus on its metrology problem rather than the metrology process.
In this case, the surface roughness on the drill bit for the simple changes in critical surface finish that could impact the tool’s longevity. They set up a testing regime to identify parameters to ensure production was within specified parameters (see tables 1 and 2).
In addition to the QC applications of NPFLEX, the tooling manufacturer’s R&D group was able to utilise the tool for more extensive material and tribology analysis. Studies were conducted on high-speed steel drill bits used to drill into anodised aluminium plates. Data was collected from three distinct regions of the drill bits (see figure 5).
It was found that the radii of curvature and edge quality remained unaffected but the Str parameter (which helps determine lay or recurring pattern) and bearing ratios changed after certain usage amounts (see figure 6).
This indicated that although initial drill bit usage smoothed the surface (as indicated by results in figures 3 and 4) further prolonged usage caused decreased smoothing. The images obtained actually showed significant material re-deposition occurring upon
<< Table 2: Used drill bit roughness parameters. >>
26 | commercial micro manufacturing international Vol 7 No.1
<< Table 1: New drill bit roughness parameters. >>
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52