Page 370 - Gear Technology Solutions

Figure 17: Two-face vs. Three-face nominal CMM data file

In case of 3-face ground blades used in a cutter head with 12° slot inclination
to cut a bevel gear, it is possible to use the parallel generated A3F-file, with the
effective blade geometry and go the path to generate the CMM-effective-
geometry calculation (bottom right in Figure 17) and measure the parts with
this coordinate file (left pointing blue arrow to center bottom graphic in Figure
17).

In cases where the post revision blade 3-face blade calculation is used and if
the effective blade hook angle is between -1° and +1°, then the manufactured
bevel gears can be directly measured with the standard CMM-download file
(calculated for 2-face blades in a cutter with 4.42° slot inclination) which is in-
dicated with the red arrow in Figure 17.

26.7 Example Results with Pre- and Post- Revision Software

In order to judge the cutting results after the software revision, some baseline
calculations have been made and will be discussed in the following paragraph.
All measurement results in this section result from blades ground on the same
BPG blade grinder which have been used to cut sample pinions on the same
Phoenix® cutting machine by utilizing a cutter head with 4.42° slot inclination
and a cutter head with 12° blade inclination. The “Sum of Errors Squared” is
defined as the summation of the squared deviation amounts of all 90 surface
grid points (of both flanks, measuring a 9 x 5 grid). Per convention, the unit

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