Page 369 - Gear Technology Solutions

Figure 16: Effective blade geometry output in program TREFACE

26.6 AF3 Feedback File to Create a Relevant CMM-File

The goal of a 3-face ground blade is to duplicate the theoretical blade geome-
try, used during the flank form and tooth contact analysis development. This
theoretical blade has in all common cases a standard 2-face geometry. The
decision, which system is used (2-face or 3-face) and the decision which par-
ticular angles (especially the effective cutting edge hook angle) will be chosen
for a 3-face blade geometry is made long after the original design calculation
was conducted. In cases where the effective cutting edge hook angle of a 3-
face blade geometry deviate largely from the original 2-face blade, a specially
calculated feedback file (A3F-file) can be used to calculate the actual flank
form of the gears which will be later manufactured with these blades (software
function “create effective design”). The A3F-file contains the effective 3-face
blade geometry and is processed in the standard flank form generator.

The two possibilities to arrive at a coordinate file for 3-D flank form measure-
ment are shown in the data flow and processing chart in Figure 17. It begins
with the basic settings and basic blade geometry AAA-file or SPA-file. The
standard case is the CMM-download file calculation for example in CAGE
(Figure 17, bottom left). Parts cut with 2-face blades in a cutter head with 4.42°
slot inclination are measured directly with this CMM-download file (right point-
ing blue arrow to the center bottom graphic in Figure 17).

354